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Some seriously powerful (and free) PDF functionality in PowerApps and Flow

Hiya

Pretty much every time I run a project kick-off meeting involving tools like SharePoint or PowerApps, I always ask the group the following question:

“If you had <insert goal here>, how would things be different to now”?

(Replace <insert goal here> with any common IT platitude like “improved collaboration”, “knowledge management”, “big data analytics” or “digital transformation”. )

Now inevitably, someone will say something like “I would have information at my fingertips”. While that may sound like a cliche, these days, it is pretty easy to meet this goal. So easy in fact, that I can do it in around 10 minutes using a SharePoint Document Library, a quick PowerApp and a Flow of only 5 steps. I then get to be a smartass, hand them my phone and say “there you go – at your fingertips… That’ll be $250 thanks”.

Now if you want to score $250, I have bad news for you. No client has ever actually paid me when I used that line. But nonetheless, if you have been looking for a demo to show just how powerful these tools have become, then one is pretty good… If you check the image below, you can see I have a PowerApp that is browsing a SharePoint document library and irrespective of whether the document is Word, Excel or PowerPoint, is loading it as a PDF into PowerApps for preview. Better still, this solution is very much in the citizen developer realm…

A common use-case for this sort of solution is a field worker who needs to access schematic data like drawings or equipment documentation. I have also deployed something similar for quality management and safety apps. In all cases, users had a need to be able to retrieve documents quickly and easily…

How to build this app

This app consists of a simple PowerApp, a SharePoint doclib and a 5 step Flow.

Step 1: Create a document library in SharePoint – in my case I called my library “FingertipsBaby”…

 

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Step 2: Start PowerApps studio and make a blank tablet app.

Step 3: Connect the document library as a data source using the SharePoint connector. Note, although document libraries are not listed by default, you can definitely connect them. Just scroll to the end of the lists and in the last box, type in the name of your document library…

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Step 4: On the left side of the screen, add a blank vertical gallery and linked it to the data source.

Step 5: Add a label to the gallery and set its Text property to ThisItem.’{FilenameWithExtension}’. If you check the image below, you can see my three documents listed from my library. Not pretty I know, but this is a 10 minute demo remember?

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Step 6: Go to the Action menu and click the Flow icon. in the Data panel that opens on the right, click Create a new flow. A new tab will open in your browser and log you into flow. A new flow will be created using a PowerApps trigger as shown above. Take the opportunity to give your flow a name, such as “PDF Viewer”

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Explanation interlude:

Now at this point I feel some explanation is needed. We are about to use a few recent enhancements to Flow and SharePoint. Kudos needs to go to Brian Edwards who made me aware of a powerful new SharePoint API that among other things, generates thumbnails and PDF’s of documents. Brian already has a blog that explains how to do thumbnails – so consider this article a companion one that does PDF’s.

The key to the whole thing is an API called RenderListDataAsStream. This is a very powerful API that has a truckload of goodness, but for now I will keep it simple. I will pass a SharePoint List Item ID of a document to the API and it will give me back a PDF. The API call looks like this:

_api/web/lists/GetbyTitle(‘FingerTipsBaby’)/RenderListDataAsStream?FilterField1=ID&FilterValue1=<List Item ID>

In the body of the request, I need to specify the data I’d like returned. The parameter is called RenderOptions and looks like this:

    “parameters”: {

       “RenderOptions” : 4103

    }

)

What is the deal with the number? Well, the documentation includes a table of different interesting things you can return, which you can do by adding the Values together.

 

Label Description Value
ContextInfo Return list context information 1
ListData Return list data 2
ListSchema Return list schema 4
EnableMediaTAUrls Enables URLs pointing to Media TA service, such as .thumbnailUrl, .videoManifestUrl, .pdfConversionUrls. 4096

So we are asking this API not just to bring back the data associated with a list item, but also some additional useful stuff. The last entry is particularly interesting as it mentions a mysterious beast known as the Media TA service which I assume means “translation”. Basically what happens is if we total the numbers listed in the above table (4103), we will end up all the data we need to do PDF conversion.

Now at this stage, I don’t want to do an exhaustive examination of the JSON data returned by this API call, but I will call out a couple more things before we get to flow…

First up, you will find this entry…

“.pdfConversionUrl”: “{.mediaBaseUrl}/transform/pdf?provider=spo&inputFormat={.fileType}&cs={.callerStack}&docid={.spItemUrl}&{.driveAccessToken}

This parameter refers to a URL that will convert the list item to a PDF. All you need to do is access this URL. How easy is that eh? Now all of the stuff in curly braces are tokens but they are also returned as part of the API call, so they can be grabbed from elsewhere in the output. For example, {.mediabaseURL} is a few lines up and in my case is:

“.mediaBaseUrl”: “https://australiasoutheast1-mediap.svc.ms”

So if we find each token in the .pdfConversionUrl and replace them, we basically have converted our document to PDF without needing to store a PDF. The document can stay in its native format!

Back to Work…

Okay so let’s deal with this flow.

Step 7: Add an SharePoint action called Send an HTTP Request to SharePoint to the flow. Set the Site Address to the site that contains your document library and set the Method to POST. Set the URI to _api/web/lists/GetbyTitle(<docLib>)/RenderListDataAsStream?FilterField1=ID&FilterValue1=, where <Doclib> is the name you specified for the document library (for example, mine is _api/web/lists/GetbyTitle(‘FingerTipsBaby’)/RenderListDataAsStream?FilterField1=ID&FilterValue1=). On the end of the URI, click Dynamic Content and choose Ask in PowerApps as shown below:

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Step 8: In the Body section, paste the following configuration (watch the quotes when pasting from this article):

    “parameters”: {

       “RenderOptions” : 4103

    }

}

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Step 9: Click the Save and then Test icon in the top right. Choose the option I’ll perform the trigger action and click the Save and Test button. Click the continue button and on the next screen, type in the ID number of one of the documents in your library and click the Run Flow button. Your flow will start and you can click Done. Assuming it worked, you will see a green tick of happiness.

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Step 10: Click on the Send an HTTP Request to SharePoint action to expand it. We need to grab the output from the API call for the next action. Find the OUTPUTS section and copy the entire contents to the clipboard….

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Step 11: Go back to edit mode and add a Data Operations action called Parse JSON to your flow. This action will allow us to make use of the output of the API call in the subsequent flow step.

Click the Use sample payload to generate schema link and paste your clipboard contents into the window and click the Done button. In the Content field, go to Dynamic content popout and choose Body from the Send an HTTP Request to SharePoint action.

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Step 12: Add an Initialize Variable action to your flow. Name the variable PDFURL (or something similar) and set it to a string. Now we come to the most complex bit of the flow where we have to substitute the token we examined in the interlude earlier. Be careful here… this is the most likely place to make an error…

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In the Value textbox, click the dynamic content flyout and find .mediaBaseUrl from the Parse JSON action…

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Next, add the following text to the Value textbox, taking care not to delete what you just added in the previous step. <edit>Please note the image has a quote that is not meant to be there, so ignore it!</edit>

/transform/pdf?provider=spo&inputFormat=

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Now we come to a slightly tricky bit. The next bit of content we need is the file type of the document we are dealing with. Now this is formatted as a single value array, so despite there being only a single value, we need to create an expression to handle it. Click the Expression tab and type in the following:

first(body(‘Parse_JSON’)?[‘ListData’]?[‘Row’])?[‘File_x0020_Type’]

For the uninitiated, this is known as Workflow Definition Language and is well worth learning…

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Next, add the following text to the Value textbox, taking care not to delete what you just added in the previous step.

&cs=

Also be super careful here because at the time of writing, the cursor in this textbox can randomly move and wipe out your edits…

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Now in the Value textbox, click the dynamic content flyout and find .callerStack from the Parse JSON action…

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Next, add the following text to the Value textbox, taking care not to delete what you just added in the previous step.

&docid=

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Now we come to another array that needs to be handled. This is the URL of the document we are dealing with. Click the Expression tab and type in the following:

first(body(‘Parse_JSON’)?[‘ListData’]?[‘Row’])?[‘.spItemUrl’]

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Okay we are almost done… Add an ampersand ( & ) to the Value textbox, and then click the dynamic content flyout and find .driveAccessToken from the Parse JSON action…

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Step 13: Add a the PowerApps – Respond to PowerApps action to the flow. Click the Add an output icon and choose Text from the list of output types. Name the output PDFURL and set the value to the variable you created in step 12 (PDFURL).

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Ok we completed the flow. Save it and give it a quick review. It should look something like this…

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Step 14: Back in your PowerApp, now, select the label gallery you created in step 5. From the Action menu, choose Flow and you should see your newly created flow listed. Click on it to add it to your PowerApp. Once added, the label will partially fill in the OnSelect property to run your flow.

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Step 15: Complete the flow invocation by adding a reference to the ID of the document from the gallery by using the following function:

Set(PDF,PDFViewer.Run(ThisItem.ID))

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This function will set a variable called PDF to the output from our newly minted flow. When you click on a file in the gallery, the flow will get called. In fact you can try this out before we move on. Press the play icon to test your app and click one of the files. Then go back into edit mode and click the Variables icon from the View menu. You should see a global variable called PDF that has a data type of record.  Clicking the variable will bring up further details and if you click on the record icon, you will see the output returned from flow.

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If you get this far, that’s great because you are almost home….

Step 16: From the Insert menu, Add a PDF Viewer from the Controls menu. Place it to the right of the gallery and set the Document property to PDF.pdfurl. (if you look closely at the above image you can see that PowerApps has decided that the output of the API is a record with a column name of pdfurl).

Now click on some of the documents… if you did it correctly, you will be seeing PDF’s!  Wohoo! Smile

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Conclusion

Not bad eh? A 5 step flow has enabled a very powerful use-case and once again showcases how well PowerApps and Flow work together. I should note that there are three recent innovations that have enabled this scenario, namely the recent Send an HTTP request to SharePoint action, the RenderListDataAsStream API and the Respond to PowerApps action.

I need to also give credit to my daughter Ashlee, who actually figured a lot of this out earlier in the week. We will record a video on this fairly soon to accompany this post.

If you got value out of this post please let me know. I’d love to hear of other use-cases of variants on this approach

 

Thanks for reading…

 

Paul Culmsee

 



Three ways to convert HTML to PDF using Microsoft Flow

The ability to generate PDF’s as part of a business process is a common one – mainly driven by compliance. A common way to do this is to create a HTML file and then convert that to PDF.

<TLDR>Go to the conclusion for a summary of the approaches</TLDR>

In Microsoft Flow, there has been options for doing this for a while now. For a start, there are two 3rd party flow actions available that are part of a broad suite of tools for managing and manipulating documents. They are Muhimbi PDF and Plumsail Documents.

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Both offerings are simple to set up and use. They also allow some configuration and tuning. At the time I wrote this article, both allow you to specify page size and orientation, and Muhimbi has a couple of extras like letting you make password protected PDF’s. As they are both commercial tools, these will come at a cost which depends on how many PDF’s you produce. But in saying that, the cost is not particularly excessive.

Below I show you both actions in use. Each one is followed by an action to save the PDF into my OneDrive – easy peasy…

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But I am cheap Paul!

For those of you who do not have a budget, or are simply cheap-assed, there is also the OneDrive Convert File action. This one works by saving a HTML file to OneDrive (or OneDrive for Business). You then pass that file into the Convert File action and save the resulting PDF. So instead of two steps like the ones above, you have three.

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Head over to John Liu’s page for a great example of this technique…

Now there is only one teeny problem with this. Not so long ago Microsoft broke it and as I type these lines, it remains broken but with a commitment to get it fixed…

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Now by the time you read this it may well be fixed, but you need to be aware of another limitation with this approach. Unlike Plumsail and Muhimbi, this converter does not honour css page breaks. Therefore your PDF can end up looking pretty ugly as content wraps over pages in ugly ways…

Is there another option? Why bother?

So you might be thinking, okay so just use one of the commercial offerings while Microsoft sorts out a fix? After all, even if it costs you a few backs, you can always go back to the cheap version later.

I indeed attempted this but I had an issue with my Flow that precluded it. I had no problem signing up for both Muhimbi and Plumsail, but when I added the actions to my flow, I was met with this type of error. My flow simply did not like using 3rd party connections it seemed.

Unable to process template language expressions in action ‘Convert_HTML_to_PDF’ inputs at line ‘1’ and column ‘2336’: ‘The template language expression ‘json(decodeBase64(triggerOutputs().headers[‘X-MS-APIM-Tokens’]))[‘$connections’][‘shared_muhimbi’][‘connectionId’]’ cannot be evaluated because property ‘shared_muhimbi’ doesn’t exist, available properties are ‘shared_sharepointonline, shared_onedriveforbusiness’. Please see https://aka.ms/logicexpressions for usage details.’.

Now this error is the subject of an open case with Microsoft so I will update this post when I get an answer. <update> It turns out that for flows with a PowerApps trigger, you need to disconnect and reconnect it to PowerApps to start working</update>. But in the meantime I had a deadline and had to demo PDF creation to a client. So I decided to make an Azure function and call it from flow – after all it sounded like a perfect scenario for that technology right?

Now I won’t cover the Azure function stuff in depth here, except to say I tried a heap of HTML to PDF approaches and not a single one worked properly. Eventually I worked out that Azure functions restrict the use of GDI+ libraries. Quoting from the linked article…

For the sake of radical attack surface area reduction, the sandbox prevents almost all of the Win32k.sys APIs from being called, which practically means that most of User32/GDI32 system calls are blocked. For most applications this is not an issue since most Azure Web Apps do not require access to Windows UI functionality (they are web applications after all).

However one common pattern that is affected is PDF file generation

Eventually though I was able to ascertain that if you provision your azure functions using an app service plan instead of a consumption plan, it will work. The reason for this is the latter runs on dedicated virtual machines.

Of course now you are up for hosting costs for your app plan. Unless you already have an Azure function app provisioned for other purposes, this is no longer free.

Once I got past the Azure function issues with GDI support, I was easily able to find and use a pre-existing HTML to PDF function found here. This uses a tool called wkhtmltopdf which is a pretty powerful PDF generation library. I simply added the necessary files and configuration and was able to test it successfully in minutes.

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Finally all I needed to do to call this function was to create a HTTP action in Flow like so…

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Yay! I had my PDF’s!! Even better, this approach does not have the page break issues that the built-in one does!

Conclusion (and comparison)

So here is a little table that summarises the approaches…

 

Method Cost Page Breaks Features Complexity
OneDrive Convert File Action Free No Basic Low
Plumsail HTML to PDF action Not Free Yes Medium Low
Muhimbi HTML to PDF action Not Free Yes Medium+ Low
Azure function Not Free1 Yes Advanced Medium2

 

1 You will have to pay for the azure function app subscription, but many orgs will have one already so might be very low.

2 I marked this as medium if you are doing basic stuff, but if you want to do stuff like set page size and orientation, you are having to edit code directly so could be classified as High.

 

Now for my real use-case, I would likely use one of the commercial offerings, but if the organisation was going to do a lot of PDF generation, then the Azure function approach could be quite cost effective. Additionally, expanding the code to deal with additional options might also be justified.

I think the key point is that I was able to quickly work around this issue and deliver good outcomes for my client. So they are not adversely impacted while I wait for the various issues to be resolved.

Thanks for reading

Paul Culmsee

www.hereticsguidebooks.com



How to make a PowerApps activity feed via SharePoint search–Part 3

Background

Hi and welcome to the third article that describes how to make a PowerApps-based activity feed based on SharePoint search results. If Google’s search algorithm has landed you here for the first time, then I suggest going back to parts 1 and 2 for background and context. What we are building can be seen in the picture below highlighted red..

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Now there are 5 parts to this solution and in this third post, we are in the home stretch because we have done the first three steps and we are halfway through part 4.

  1. Setting up SharePoint search
  2. Querying the search index via a PnP PowerShell script
  3. Creating the Azure function
  4. Creating the custom connector
  5. Testing in PowerApps

I covered parts 1 and 2 in the first post where we created a Result Source in SharePoint and and tested a PowerShell script that uses it to bring back the latest 20 search results. In the second post, we created and tested an azure function, and just deployed our custom connector as shown below:

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Before we rush off to PowerApps to bask in our awesomeness, let’s test our custom connector first. Click the pencil button to edit your freshly minted connector. Using the breadcrumb, navigate to the Test menu.

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You will be presented with a Test operation screen and (very likely) a prompt to create a connection. While newbies might find it weird to ask for a connection just after we just made one, it is worth paying close attention to the terminology used. We actually created a custom connector, not a connection. The PowerApps team describe it like this:

Data is stored in a data source, and you bring that data into your app by creating a connection. The connection uses a specific connector to talk to the data source

Therefore, it stands to reason that to test a connector, one has to create a connection. So let’s do that right now by clicking the + New connection button. On the resulting confirmation dialog box, click Create.

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Now you will be redirected to the connections screen. This is somewhat counter-intuitive given at first, since we actually wont do anything with the connection from this screen, but if it makes you feel good, feel free to look for a new connection with the same name as your connector as shown below. This means all went to plan…

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Using the left side navigation, head back to the custom connections screen. Edit your connector once again, and navigate back to the Test screen. This time the Test Operation screen will show your new connection listed…

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Scroll down and you will see an Operations section. The code query string parameter that we worked with in part 2 is listed.

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Note: It should be greyed out and not editable. If it is editable, you have likely forgotten to change the visibility parameter when we created the custom connector in part 2.

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Click the Test operation button to give it a whirl. After a few seconds, you should see a successful response. Looking in the body of the response, you can see the Json search results produced by your Azure function. Yay!!

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Part 5 – Testing in PowerApps

Now that we have created a connection and used it to test our custom connector, it is time to move to PowerApps. To keep things simple, lets build an app from scratch to show this working. In PowerApps studio, create a blank phone app and then follow the steps:

1. From the View menu, choose Data sources and click the Add data source from the Data panel. From the list of connections, find the connection we created moments ago to test the connector. Click it and it will be added to the app.

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Note the name of your connector matches the Postman collection we created in part 2 of this series. Make a note of this because we will need it momentarily…

2. From the Insert menu, choose Icons and choose the Reload icon.

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Select the refresh icon you just created and choose the OnSelect property. Type in “ClearCollect(Feed,” and then enter the name of the data source you just added (mine is called “CATalogue”). The intellisense in PowerApps will also present the name of your function that you specified back in part 2 when creating the postman collection. In my example it was called “GetMewsFeed”.

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Note: If you are presented to provide a code as a parameter to your data connection as shown below, you missed an important step in the custom connector setup. Recall in part 2 I mentioned that the code parameter in the custom connector had to be changed from none to internal. For now, you can add the same code that was generated as part of the Azure function URL, otherwise update the custom connector.

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3. Click the new icon to trigger a data refresh and then navigate to Collections from the File menu. You should see a collection called Feed with some of the data returned. If you see a table of data then congratulations! You have successfully queried SharePoint search and returned the data to PowerApps via an Azure function.

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The columns that are of interest to us for the purposes of this post are:

  • Title
  • ListID
  • ModifiedBy
  • LastModifiedTime
  • OriginalPath

So now that we have gotten some data, let’s now show how we can display it in the form of a data feed.

4. From the Insert menu, choose Gallery and pick a Blank flexible height gallery. In the data panel, choose the Feed collection from the Data source dropdown.

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5. Ensure your Gallery is still selected via the left side navigation. Click the pencil icon inside the gallery and then from the Insert menu, choose Label. This label will bind to a column in your data source and you should see something like the second screen below, where data is repeated down the page. If the label control is still selected, the Text property will be set to something like ThisItem.Author.

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Modify the Text property of the label to “Updated by ” & ThisItem.ModifiedBy & ” on ” & ThisItem.LastModifiedTime. The result is a line that shows who modified the item in the feed and when they modified it. While you are here, rename this label control and call it something more meaningful. In PowerApps I use Hungarian notation as it makes it easier to understand complex formulas later. Thus I called this one lbWhoWhen. Finally, resize the gallery to fit the screen and drop the font size of the label so everything fits on one line…

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6. Add another label to the gallery (remember to use the pencil icon to ensure the new label control is added to the gallery and not the screen). Place it below the label you created in step 5 and set it’s text property to ThisItem.Title. Adjust the font size and position it appropriately. Rename this label to something meaningful (I used lbTitle ).

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7. Add an icon to the screen and choose Rectangle from the Shapes section. Resize it so that it looks like a horizontal line (Set the Height property to 1) and change its colour to grey either via the toolbar or via setting the Fill property to “LightGray”. Also rename it to something like Separator.

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Preview the app and the feed should start to take shape…

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Hopefully you can see by now that we are more or less done, as we are now moving into aesthetics in terms of how our feed is to look. So I will round out this post by showing you a couple of tricks that I think make this feed more interesting…

6a. Pimping your feed (easy)

If you look closely at the sample data I used to build this feed, it includes images as well as list item content. In fact, to remind you of where we started, I mentioned that my daughter wrote an app called CAT-alogue which used three SharePoint lists/libs: There was a list called Cat Directory, a list called CatImageRegister and a library called CatImages.

So let’s make the following enhancements:

  1. If the search results contain a Description field, use that instead of the Title field (the Cat Directory list utilises the built-in SharePoint site column called Description, which happens to be a managed property in SharePoint search)
  2. If the search result is the image library, display the image rather than the file name.

Handling description requires a couple of changes to our Title label. First, we need to set Auto height to On because the description field is multi-line. This is easiest done by toggling it to On via the right-side properties panel when selecting the label as shown below:

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Next, change the Text property in the label to If(IsBlank(ThisItem.Description),ThisItem.Title,ThisItem.Description). This tells PowerApps to display the Title field if no description has been crawled. The effect should be immediate…

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But this is a flexible height gallery, so let’s take advantage of this. We will now set the position of our separator rectangle to be based on the height of the Title/Description label. Remember this label is now set to auto-height… To do this you will need to take note of the name of your Title/Description label. Mine is called lbTitle.

Set the Y property of your rectangle to: lbTitle.Y + lbTitle.Height + 20. Previewing this change should result in a change to your screen for the better…

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6b. Pimping your feed (less easy)

Right! So what we can do about displaying images in the feed? Turns out this is one of those examples that might seem easy, but is actually quite tricky and also not particularly bandwidth efficient either. It also has a lot to do with how you set up your data in SharePoint, so some refresher is needed before we start.

First up, Ashlee’s CAT-alogue app is structured with 3 lists. There is a list called Cat Directory, a list called CatImageRegister and a library called CatImages. The second list is the one that matters here, as each time a photo is taken, the metadata is stored in this list rather than the CatImages library. It then links to the actual photo in CatImages as shown below. Note that the title field for CatImageRegister is the name given to the photo in CatImages.

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Why set it up this way you ask? Well for a start, PowerApps cannot connect to libraries yet, and these days, PowerApps is smart enough to be able to retrieve images from a list like this. So let’s take advantage of this…

Also some more useful nuggets of context: another thing we can take advantage of is the built-in SharePoint search property called ListID. Way back in Part 2 when we did the PowerShell script, I included a line that specified some search managed properties to be returned that are not by default. The line was:

$returnproperties = @(“ContentType”,”ListID”,”ModifiedBy”, “ListItemId”)

Specifically, the property of ListID is what matters here. This property returns the unique ID of each list. Can you see where I am going with this yet?

From the Insert menu, choose Media from the toolbar and insert an Image control into the gallery. Rename it to CatPhoto and resize it and place it under the first label.

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Set the Visible property to only display if the list ID of the feed item is the CatImageRegister list. It will be something like: If(ThisItem.ListID=”11d474d0-5725-4ec5-b273-8bb09a3e097e”,true,false). Of course the ID you need to specify depends on our setup. This should now hide the image control when the ListID does not match my CatImageRegister list.

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Next, let’s get the image control to display the photo itself. To do this, we will connect to SharePoint using the native PowerApps connector. From the View menu, choose Data Sources and add a SharePoint data source. Choose the SharePoint list that holds a link to your photos (in my case, CatImageRegister).  

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Now set the Image property of the Image control to something like this: LookUp(CatImageRegister,Title=ThisItem.Title).CatImage. Although things look ugly, you should see the photos…

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So what we did here was utilise the PowerApps Lookup function which returns first record in a data source that satisfies a formula. In my case I wanted to bring back the record where the Title field in CatImageRegister matched the Title field for each row in the feed gallery. From here, I specified that I specifically wanted the CatImage property and voila!

Next, we make the feed look less sucky by making the position of the Title/Description label more dynamic. If an image is displayed, we will reposition the Title/Description label to the right of the image. To do this, set the X property of the Title/Description label to: If(CatPhoto.Visible,CatPhoto.X + CatPhoto.Width + 10,0). This tells PowerApps to shift the label to the right of the image control when it is visible and sets the X position to 0 when its not.

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Now let’s set the Y position. In this case, if the image control is visible, let’s vertically align the label to the middle of the image control. But if the image control is hidden, let’s set the label to positioned relative to the top label. To do this, set the Y property of the Title/Description label to: If(CatPhoto.Visible,(CatPhoto.Y + CatPhoto.Height) / 2,lbWhoWhen.Y + lbWhoWhen.Height + 10).

Nice… the feed is looking a lot tidier…

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Now let’s fix the separator rectangle we created earlier. Here, if the image control is visible, the Y position of the separator should be offset from it, however if the image control is hidden, then it should be based on the Title/Description label. To do this, set the Y property of the separator to: If(CatPhoto.Visible,CatPhoto.Y + CatPhoto.Height + 20, lbTitle.Y + lbTitle.Height + 20).

Preview the app and you should have yourself a nice feed!

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Conclusion

At this point, I think we have covered enough to give you a really good feel for how PowerApps an play nicely with SharePoint search and Azure functions. While I fully accept this is an advanced scenario for the typical citizen developer, it is still a very low-code scenario and working knowledge of Azure functions and PowerApps/Flow custom connectors is very handy indeed.

I think it also shows that these platforms are highly flexible. This activity-feed scenario was one of those tricky scenarios that in the past, might have been added to the “too-hard” basket or resulted in custom development work.

Finally, I have recorded a series of videos to accompany these posts. I split the videos up into easy to consume chunks. The first one can be found below:

 

Thanks for reading

 

Paul Culmsee



How to make a PowerApps activity feed via SharePoint search–Part 1

Background

In a recent project, I developed a portal for the Project Management function of a global multinational. One of the key design principles we took into the engagement was not to simply make an electronic version of a Project Management manual. Instead, the solution had to be a source of new and timely information that would keep people coming back, as well as actively contributing.

One of the many things done to achieve this goal was to create a PowerApp to compliment the portal. This app, among other things, allows users to submit project tips, lessons learnt, participate in pulse surveys, and receive notifications when particular topics (for example risk management or project controls) have new or updated information. A key feature of the app is an activity feed showing the latest information across the portal. The basic idea is shown in the wireframe below, where under the main navigation represented by the round icons, users can view and click on any new activity that interests them. Activity reports include new or updated content, newly submitted tips, photos, and lessons learnt.

image_thumb11

The data for this application is stored in SharePoint, so activity occurs across multiple lists/libraries. Therefore to produce an activity feed, PowerApps needs to talk to SharePoint search. Search, via the concept of a Result Source, allows us to specify exactly what lists and libraries are used in search results. This is important because we also want to exclude some SharePoint content from the feed. After all, if you maintain a list that is used to store and manage configuration data, it’s unlikely that you want blast out changes to that list to all users via an activity feed.

Result Sources also allow us to specify the ranking model on the results, which for an activity feed is usually based on date modified (i.e. recency rather than relevance).

Now I can’t show you the actual solution for confidentiality reasons, but luckily for all of us, my cat-obsessed daughter Ashlee (of fidget spinner fame), created a PowerApp called the CAT-alogue which is shown below. So in this post, I will explain the approach to the activity feed using the CAT-alogue via a feature called the (ahem) “Mewsfeed”…

image_thumb48

The Solution

Below is a diagram of the approach I ended up taking.

Snapshot_thumb

As you can see, the main components are:

  • A custom SharePoint Search Result Source
  • An Azure function (leveraging PnP PowerShell)
  • A PowerApps custom connector

Now I should say this was not my original approach. I started off assuming that I’d query SharePoint search via Flow, using HTTP actions to talk to the SharePoint Search REST webservice. This approach has worked well for me when I needed to leverage unsupported SharePoint functions in PowerApps or Flow. But there was one major issue that was search specific. That is, when you talk to SharePoint REST API using Flow, you need to register and specify an App Principal for authentication. Now this is supported in SharePoint online search, but has an implication. There is no security trimming of search results. Quoting from the referenced article

When you are using SharePoint Online search APIs with app-only permissions, you will need to request full permissions to the tenant when you are registering the add-in/app for the tenant. This will grant needed permissions to query information from the Office 365 tenant without security trimming applied.

For some scenarios this might be fine, but in my case, the idea of an app being able to query any/all SharePoint content in the entire tenant was never going to fly. My alternate approach uses the more traditional technique of a dedicated user account to access SharePoint. Thus, if the account only has access to this site, we have the search security trimming we need.

Right! Lets get down to business then. I have broken this into 5 parts across a few articles:

  1. Setting up SharePoint search
  2. Querying the search index via a PnP PowerShell script
  3. Creating the Azure function
  4. Creating the custom connector
  5. Testing in PowerApps

By the way, don’t let the length of this series put you off. I have tried to explain things as best I can with liberal use of screenshots.

1. Setting up SharePoint Search

The first step is to make a SharePoint result source which specifies the content that will be viewed in an activity feed. In my developer tenant, my daughter’s CAT-alogue app uses a list called Cat Directory, a list called CatImageRegister and a library called CatImages. If any activity happens in any of these lists, we want to see it on her app.

I decided to create a Search result source, using the List IDs as the filter. Note that this is not the only approach to take for this result source, but will suffice for my needs. To get the IDs of the lists in question, I used PnP PowerShell. After connecting to my tenant, I used the Get-PnPList command to find all lists with the word “Cat” in their Title like so…

image_thumb3

PS C:\Users\paulc> get-pnplist | Where Title -Like "*Cat*"

Title                               Id                                   Url
 -----                               --                                   ---
 Cat Directory                       2b4ee9b8-714e-464d-a8ae-ab379776c826 /Lists/Cat Directory
 CatImageRegister                    11d474d0-5725-4ec5-b273-8bb09a3e097e /Lists/CatImageRegister
 CatImages                           c5b56dac-b7f1-4519-b7e6-ac688ac158dc /CatImages
 Notification List                   3a649e3a-6473-4f73-b856-31740368369c /Notification Pages
 Suggested Content Browser Locations e6e70c65-096b-4733-ad03-c86e25708f05 /PublishedLinks

I strongly suggest you use this method to get to know the awesomeness that is PnP PowerShell if you are new to it. But for the holdouts who think PowerShell is for developers, if you want to get the list ID’s via the SharePoint UI, you just need to go to List Settings and check the URL as shown below.

image_thumb5

Once you have assembled your list ID’s, you can create a result source. Go to Site Settings > Site Collection Administration > Search Result Sources and choose to create a New Result Source. Give your result source a name. Ashlee made me call it “Mewsfeed” – honest!

image_thumb14  image_thumb91

Scroll down and find the Launch Query Builder button. From the Property Filter dropdown, choose –Show all managed properties– and find the ListID property. In the property filter, choose Contains and choose Manual Value from the Select Value dropdown. Specify the ID of one of the lists as shown below:

image_thumb7

image32_thumb

Repeat these steps for each list ID and click the Test query button to validate you are getting results.

image_thumb201

At this point, if you look closely at the search results, you will likely see items that should not be included in an activity feed. In the picture below I’ve demonstrated this by highlighting some results I’d rather not see. To address this, let’s refine the result source to only bring back list items, rather than the list views themselves. From the Property Filter dropdown, choose contentclass property. In the property filter, choose Equals and choose Manual Value from the Select Value dropdown. Set the value to “STS_ListItem_GenericList” as shown below:

image_thumb22

image_thumb24

Now re-test your results. You should see that the unwanted pages are now excluded from results. Go ahead and save your result source with an appropriate name.

image_thumb27

2. Querying the search index via a PnP PowerShell script

Now that we have our result source, we need to write a PowerShell script to query it. First up, we need to get the ID of the result source we just created because it is needed by the PowerShell cmdlet we are going to use. To do so, select the result source and grab the ID from the URL as highlighted below…

image_thumb1

The ID has been encoded, so the best step is to use an online decoder to get the ID in the right format. Bing has one built in so just paste the ID into it and click Decode.

image_thumb31

Next step is the script which, thanks to the PowerShell PnP project, is really simple since PnP includes a dedicated command that we can use, namely Submit-PnPSearchQuery. If you are using PowerShell interactively, a search can be performed in a couple of lines: E.g.

1. Connect-PnPonline https://culmsee.sharepoint.com
 2. $result = Submit-PnPSearchQuery -Query "*" -MaxResults 20 -SourceId "0bfa50f5-041d-40af-a6e1-8b01124eca69" -SortList @{"LastModifiedTime" = "Descending"} -RelevantResults
 3. $output = $result | ConvertTo-Json

The first command connects to the tenant and will prompt for credentials.

The second command performs a wilcard search (-Query “*”), returns 20 results (-MaxResults 20) and specifies the result source set up earlier (-SourceId “0bfa50f5-041d-40af-a6e1-8b01124eca69” ). We sort the results via recency (-SortList @{“LastModifiedTime” = “Descending”}  and instruct the command to strip out extra detail and bring back just the results (–RelevantResults).

The third command converts the output to Json format and stores it in the $output variable, which is important because this is what we will send back to PowerApps.

To test that this is working as expected, I compared the results of a more simplified search. In the example below I have searched for the term “Jessica” – the name of one of Ashlee’s cats. First, I tested via the Result Source in SharePoint by returning to the query builder, navigating to the Test tab and clicking Show more

image72_thumb

I entered “Jessica” into the search term and found 11 relevant results…

image_thumb4

Now in PowerShell we see the same search for “Jessica” and take a peek at the Json. Sure enough, we have the same 11 results as the Result Source test above.

image_thumb12

So now that we have confirmed we are executing the correct search, we need to go and make ourselves an Azure function to run the script. We will do this in part 2…

 

Thanks for reading…

 

Paul Culmsee



A Sample OpenAPI/Swagger file for PowerApps

Ever since I posted a video on how to use Flow to upload photos to SharePoint from PowerApps, I get a lot of requests for help with the most mysterious bit – the swagger/openAPI file…

To save you all much pain and suffering, here is a sample file that you can use to get started.

In this post I am going to assume you have watched the video and understand the intent. Here I will simply annotate the file with some notes that will help you customise and extend it for your own purposes.

Note 1: This only works for a HTTP request trigger in Flow

Flow is capable of being called like any other web service. To do so, you have to use the following trigger.

image

Note that the trigger states clearly “URL will be generated after save”, so the first thing to do is generate that URL…

image

Once you have done so, it will look like this:

image

If we break the URL it down, you will see:

  • A domain something like <location>.logic.azure.com.
  • A URL path of “/workflows/<instance ID>/triggers/manual/paths/invoke” which  that identifies your specific workflow ID. Take note of this as you will need it.
  • A parameter called api-version with a (at the time of writing) value of “2016-06-01” – eg api-version=2016-06-01
  • A parameter called sp with an encoded value of “/triggers/manual/run” = eg sp=%2Ftriggers%2Fmanual%2Frun
  • A parameter called sv with a value of 1.0 – eg &sv=1.0
  • A parameter called sig with a random string value. eg sig=PeZc-ljtjmJhsz00SD78YrwEohTqlUxpQuc95BQQuwU

In combination, the URL looks as follows with the important bits in bold…

https://<location>.westus.logic.azure.com:443/workflows/<workflow instance ID>/triggers/manual/paths/invoke?api-version=2016-06-01&sp=%2Ftriggers%2Fmanual%2Frun&sv=1.0&sig=<signature>

The bits in bold you will need to know, because they need to be added to the OpenAPI file. Why? because this file is what PowerApps uses to construct a HTTP call to your flow.

So let’s look at the Swagger File…

Note 2: Host, basePath and Path

Open the Swagger file and look for the section called “host”… Replace the section labelled [enter Flow URL here] with the URL from the flow Trigger I mentioned above. eg:

prod-23.westus.logic.azure.com or prod-01.australiasoutheast.logic.azure.com

Note: The image below shows the port number shown (443), this no longer works so omit it altogether as shown in my 2 examples above.

From this…

image

To this…

image

Now find the section labelled [enterid here]. This is where the workflow ID goes… so from this:

image

To this..

image

Note 3: Double check the sv, api-version and sp parameter sections.

All of the parameters expected by the Flow are specified in the OpenAPI file. You will see it in the “parameters” subsection of the “post” section…eg

image

Now for reference, each parameter section has:

  • name: The name of the parameter as it appears on the URL
  • in: specifies whether this parameter is in the query string, header or body. All of the default flow parameters are in the query string.
  • default: This is the value to check!! If Flow is updated in future it is very likely this parameter will reflect it. Please do not come to me for support if you have not checked this!
  • required: States that this parameter MUST be passed. PowerApps will not allow you to call this Flow without specifying this parameter
  • x-ms-visibility: this basically says “use the default value and don’t show the user”. So in effect, the above “required” condition is met, but PowerApps will not ask the user to enter it.
  • type: is self-explanatory. It tells PowerApps that the parameter is a string.

Note: For more detail on these parameters go and read the OpenAPI 2.0 standard and Microsoft’s documentation.

Note 4: Update the sig parameter…

The sig parameter is like an API key or a password. You need to paste it as the default value in your file like so…

image   image

Note: It is possible to set this up in PowerApps so that it has to be entered when a user adds a datasource. However I am not covering that here.

Note 5: Add (and remove) your own parameters…

This swagger file makes the assumption that PowerApps is going to send a file name for the photo, as well as a description, latitude and longitude. Note that all fields are set to required, but none have default values and the x-ms-visibility parameter is not specified, meaning that PowerApps will prompt the user to enter them.

Using the examples as a guide, add or remove parameters as you see fit.

image

Note 6: Set your function call names appropriately…

Going back to the top of of the file, update the description to suit the task you are performing. Pay special attention to “Title” and “operationId”, as PowerApps uses these. For example, based on the image below, you will be calling a function called PhotoHandler.UploadPhoto() from PowerApps.

image

At this point you should be able to save your file and register it as a custom connection and call it from PowerApps.

Note 7: Do not use the word “SharePoint” in your custom  connector name

Believe it or not, if you name your custom connector with the word “SharePoint” it will confuse PowerApps completely. For example, consider this custom connector:

Now look what happens when you try to use it… you get the message “The data did not load correctly. please try again”, with a sub message of “Resource not found”…

The solution? Name your connector anything, so long as the word SharePoint is not there 🙂

Parting notes…

If you intend to send data back to Flow, you will also have the define the schema for what is returned to Flow in the responses section. I have not added any custom schema in the sample swagger file and discussing it is outside the scope of this article. But in case you are interested, to get you started, below is an example of calling Microsoft’s QNAmaker chatbot service REST API and sending the results back to PowerApps.

 

"responses": {
  "200": {
    "description": "OK",
    "schema": {
       "type": "object",
       "properties": {
          "answers": {
          "type": "array",
          "uniqueItems": true,
          "minItems": 1,
          "items": {
             "required": [
                "answer",
                "score"
             ],
             "type": "object",
             "properties": {
                "answer": {
                   "type": "string",
                   "minLength": 1
                },
                "questions": {
                   "type": "array",
                   "items": {
                      "type": "string"
                   }
                 },
                 "score": {
                   "type": "number"
                 }
              }
           }
        }
      },
       "required": [
         "answers"
       ]
    }
 }

 

Thanks for reading

Paul Culmsee



From Rick Astley to Fidget Spinners: A slew of PowerApps and Flow video tutorials

Hiya

I have been recording various videos over time of some advanced PowerApps and Flow concepts/solutions. All of these are either workarounds for current limitations in PowerApps or Flow or work I have done with my daughter, Ashlee.  I have listed each here with explanations…

How to Save Photos from PowerApps to SharePoint via Flow

This video outlines a robust and flexible method for uploading photos from PowerApps to SharePoint. At the time of writing, it is the best option despite having to create OpenAPI files.

 

Calling Cognitive Services Vision API from PowerApps via Flow

This video demonstrates a simple receipt tracker that uses the OCR capability of Microsoft cognitive services to find price information from a scanned receipt.

 

How to set SharePoint list permissions using Flow

This video shows the high level view on how Flow can be used to set SharePoint permissions, much like an app step that is used in SharePoint Designer. It also demonstrates the idea of breaking up flows into reusable chunks – called service flows.

 

It’s not a Flow, nor a Proxy… It’s a Floxy!!

This is an example of utilising flow to display document library content in PowerApps. I also wrote a detailed post about this one…

 

How To Rickroll Your Friends Using PowerApps

A funny app with some very clever design considerations. This was actually done by my daughter, Ashlee. She explains how she did it below…

 

Paul and Ashlee on PowerApps

More nerdy fun with my daughter, who is already an accomplished PowerApps coder as you will soon see. In this video, she build me a sophisticated audit/checklist app using Microsoft PowerApps and Flow. This app demonstrates offline support, calling external API’s and photo handling.

  

 

and finally….the famous fidget spinner…

Build a FidgetSpinner using PowerApps

Demonstrating the power of the PowerApps platform for citizen developers, Ashlee won a contest from Microsoft to create a fidget spinner using PowerApps. In this video, Ashlee explains to me how she built the app and shames me for my dodgy high school maths…

p.s don’t miss out the Solar System PowerApps by MVP Daniel Christian, who was inspired by Ashlee’s fidget spinner. Amazing stuff…

I think these videos highlight the flexibility and power of this platform. Let me know if you would like me or Ashlee to record others or expand on them!

Paul Culmsee



PowerApps, Flow and Managed Metadata fields–part 4

Hi and welcome to the final post in this series of articles that examined how we can work around an unsupported function in PowerApps and Flow. Along the journey we have learnt about app principals, the SharePoint REST API and written some crazy JSON.

In this final post, we will tie up a few loose ends. Currently the flow hard-codes the term ID from managed metadata when in fact, we want it to be sent from PowerApps. I will also also give you some insight into handling more complex situations, like multiple managed metadata fields as opposed to a single one.

But first, the (giant) weak spot…

As I write this I if any of you, as you read the first 3 posts, realised the weakness to this method. A strong hint was given in the last post. Recall that the JSON to update a managed metadata field required a term GUID…

{
   "__metadata": { "type": "SP.Data.Coffee_x0020_Shop_x0020_RatingsListItem" },
   "Bean":
   { "__metadata": {"type":"SP.Taxonomy.TaxonomyFieldValue"},
     "TermGuid":"0937fbc2-0dfe-439e-a24f-ba6d13897abd",
     "WssId":"-1"
   }
}

Now right now in PowerApps, there is no managed metadata control. This means you cannot browse a term store like you can in SharePoint. Among other things, one likely reason for this is that there is no REST API support for managed metadata. This has been a constant source of frustration for many as you can see in the 761 votes (as I type this) in uservoice.

What’s the implication of this limitation? For a start, there is no way we can build a REST call that will return us all of the terms in a term set. We have to either hard-code the term GUID’s in our application (ugh) or find another way to get the list of terms (ugh again). One thing that should be noted is that sometimes, hard coding terms and GUID’s isn’t as bad as it sounds. For example, you might have a term set for your corporate offices in certain countries. Since those terms are unlikely to change quickly, one can embed their GUID’s into PowerApps without too much concern.

For the first part of this article, we will use this approach and hard-code our term set of coffee beans into our Powerapp. Then we will modify our flow to expect this parameter from PowerApps.

Back to PowerApps…

If you go back to the PowerApp we built way back in part 1 and also the term set of coffee beans, they looked like this:

image  image

To hardcode our terms into PowerApps, I am going to use the ClearCollect function to create a collection called BeanDetails. I have grabbed the term label and GUID from managed metadata and constructed this function:

ClearCollect(BeanDetails,
{
   Name:  "Fiori",
   Id:  "96a085d2-ed7d-4a75-8d63-c6ca56d0b358"
},
{
   Name:  "Jungle Coffee",
   Id:  "eb04988d-acc4-4bde-9861-506e90de94c5"
},
{
   Name:  "Alfredo",
   Id:  "38db966f-3b0c-4872-a7d3-982ecd8528dd"
},
{
   Name:  "Death Wish Coffee",
   Id:  "e33c65f9-4202-40d7-89f2-aa1a1016ad9f"
})

Next, I use the OnStart property of the screen and paste the ClearCollect function as shown below.

image

Now you will need to save, close and reopen the app for this to take effect. Alternatively add a temporary button and use the above code on the OnSelect property. Either way, you should be able to see your terms and GUID’s when going to Collections from the File menu…

image

Now that we have our term set stored in PowerApps, let’s add a dropdown list to the screen that lists our coffee beans. Choose Insert > Drop Down and set its Items property to BeanDetails.

image

image

Now you should be able to see the choice of beans in the dropdown as shown below:

image

Next, we have to go back to Flow and modify it to accept a term GUID as a parameter (if you recall in part 3 the term is currently hard-coded).

Tweaking Flow…

If you have followed our Flow adventure so far, you should have a flow action called Set Test Term GUID that looks something like this:

image

First, rename this flow step to Get Term GUID and then delete the GUID that we previously had in the Value field. From the Dynamic Content pane, choose Ask in PowerApps.

image

image

Update your flow and before returning to PowerApps, click the Run Now button. Ensure you are now prompted for three parameters, rather than the original two.

image

image

Back to PowerApps…

Now in PowerApps, we have to delete and flow and re-add it so it finds the new parameter we just added.

Select the Submit button and review the OnSelect property. It should show the function below…

image

Now go to View > Data Sources and remove the NewCoffeePlace data source. You should see an error appear on the Submit button. It will say “Invocation of unknown or unsupported function”. Makes sense right? After all, we just took away its connection to flow.

image   image

Once again make sure your Submit button is selected, and select Action > Flows. Choose the flow called New Coffee Place. In a few moments, it will ask you to complete the parameters in the formula bar. If you did this correctly, you should see a prompt for a third parameter – the term GUID.  

image  image

image

The third parameter will be the GUID that matches the term in the dropdown list. The formula for this is:

image

Now to explain Dropdown1.Selected.Id, remember that we set the Items property of the dropdown to BeanDetails collection, which has two columns, ID and Name. Essentially, by specifying Dropdown1.Selected.Id, whichever bean name is the currently selected one in the dropdown, the GUID will be sent to Flow…

image

Test this by putting the Powerapp into preview and adding a new café. If all things go to plan, you will see your new entry along with the managed metadata term. Yay!!

image  image

Hard-coding sucks – surely there a better way?

At this point you might still be hating the fact we had to hard-code the term ID’s into our app. I can sympathise, as it irritates me too. So is there a way to dynamically load the term set into PowerApps? Turns out there is, provided you use an Azure function along with PnP PowerShell.

I won’t cover this in detail here, unless there is sufficient demand, but I will explain the high level overview.

  1. Set up an Azure function using PowerShell
  2. Load PnP PowerShell modules
  3. Write a PowerShell script to connect to your tenant and pull the terms from the term set.
  4. Convert the terms to JSON output
  5. Create a custom connector for PowerApps to consume it.
  6. Add the custom connector to your app, and pull down the latest term set on startup.

Now I wrote another blog post where I went through another example of using Azure functions with PowerApps, and that covers a lot of detail on steps 1, 2, 5 and 6.

In relation to step 3 and 4, here is some PowerShell code sample to do this that you can use as a starting point. Be warned though… you will need to have some understanding of PnP PowerShell to make sense of it!


Import-Module "D:\home\site\wwwroot\modules\2.19.1710.1\SharePointPnPPowerShellOnline.psd1" -Global
$requestBody = Get-Content $req -Raw | ConvertFrom-Json
$name = $requestBody.name
$username = "paul@culmsee.onmicrosoft.com"
$password = $env:PW;
$siteUrl = "https://culmsee.sharepoint.com"
$secpasswd = ConvertTo-SecureString $password -AsPlainText -Force
$creds = New-Object System.Management.Automation.PSCredential ($username, $secpasswd)
Connect-PnPOnline -url $siteUrl -Credentials $creds
$tg = Get-PnPTermGroup -Identity 2830778b-dbfa-4441-bb45-0cbb97b582e7
$ts = Get-PnPTermSet -TermGroup $tg -Identity "Coffee"
$tl = Get-PnPTerm -TermSet $ts -TermGroup $tg -Includes Terms
foreach ($term in $tl) {
   $terms+=$term.terms
}
$output = $terms | Select Name, Id | ConvertTo-Json
Out-File -Encoding Ascii -FilePath $res -inputObject $output

Like I said, if you are interested in knowing more about this, let me know and if there is sufficient demand, I will make a dedicated blog post about it…

Handling multiple managed metadata columns…

I will end this series by showing you how to handle updating multiple managed metadata columns. This is an advanced topic, but is a good test for developing JSON manipulation skills in Flow. Like the previous section I will cover it in a high level only and leave it to you to figure it out for your environment…

So far we have updated a single column, but my real-world project that led to this series actually had 3 columns that were managed metadata. What made this interesting and tricky was that these columns were entirely optional. The complexity is easy to illustrate by looking at what a JSON payload looks like when updating multiple columns. In the example below, I am updating 3 columns called ProjectType, ProjectPhase and ProjectElement respectively…

{
   "__metadata": {
     "type": "SP.Data.ProjectListItem"
     },
   "ProjectType": {
     "__metadata": {
     "type": "SP.Taxonomy.TaxonomyFieldValue"
     },
     "TermGuid": "d4e4494f-34a4-4278-b0ee-7eba372a3f80",
     "WssId": "-1"
   },
   "ProjectPhase": {
     "__metadata": {
     "type": "SP.Taxonomy.TaxonomyFieldValue"
     },
     "TermGuid": "78d647c7-8b92-4ee0-a29d-22346b1af560",
     "WssId": "-1"
   },
   "ProjectElement": {
     "__metadata": {
     "type": "SP.Taxonomy.TaxonomyFieldValue"
   },
     "TermGuid": "6f9f653f-09ec-4771-9063-676d16734b37",
     "WssId": "-1"
   }
}

Contrast the above example with the one below where only one is updated…

{
   "__metadata": {
     "type": "SP.Data.ProjectListItem"
   },
   "ProjectElement": {
     "__metadata": {
     "type": "SP.Taxonomy.TaxonomyFieldValue"
     },
     "TermGuid": "6f9f653f-09ec-4771-9063-676d16734b37",
     "WssId": "-1"
   }
}

So the trick is to build a flexible enough flow that could generate the JSON needed to update 1, 2 or 3 columns. Without knowing whether the column would have a supplied value, meant we have to find a way to handle any combination. The pattern I ended up using was to build the JSON for each of the columns individually before joining them together. Here’s how…

First, I used an Initialize Variable flow action to create the base JSON for each column. The key was to make this conditional, so if the column value was empty, I added an empty string. E.g.

image

The expression used for the value of this variable was this crazy looking Workflow Definition Language Expression:

if(not(empty(triggerBody()['GetProjectTypeTermID_Value'])), concat('"ProjectType":{"__metadata":{"type":"SP.Taxonomy.TaxonomyFieldValue"},"TermGuid":"',triggerBody()['GetProjectTypeTermID_Value'],'","WssId":"-1"}'),'')

Basically this grabs the term ID for a column (in the above example the columns is called ProjectType). I test if the column value is supplied – which is what the “if(not(empty” bit does. I then then construct the necessary JSON to update that managed metadata column. (Note if you need a refresher on the JSON in this function, review part 3)

I repeat this action for the other columns, and then perform the following steps in Flow to construct the complete JSON…

First I initialize an array variable that I call JsonPayloadArray.

image

Next I add the outer JSON for a managed metadata update to the array using the Variables – Append to array variable workflow task…

image

image

Here I am using the concat() function because I need to use the ListItemEntity variable. Note, if you have forgotten about ListItemEntryFullName property,  re-read part 3.

concat('{ "__metadata": { "type": "',variables('ListItemEntity'),'" }')

Next, I add the JSON for each column to the array, provided it is not null. I do this by adding a condition for each column.

The first image below shows the three conditions and the second image shows an expanded view of one of them. You can see in the example below, if a ProjectType was supplied, I add the variable initialized in the above steps to the JsonPayloadArray variable….

image

image

Finally, I use the Join() function to take this array and turn it back into a single string, delimited by commas. This elegantly handles the situation in JSON where the last name/value pair does not have a comma separator.  I do this by initializing a new variable called JsonPayload as a string as follows…

image

concat(join(variables('JsonPayLoadArray'),','),' } ')

Conclusion

This is one of those series that I know only a few people will get some use out of. Hopefully this whole issue of managed metadata will be gone by year-end and these approaches are not necessary. In any event the techniques outlined in these four posts apply to various other scenarios, so learning about JSON manipulation using Flow, or talking to SharePoint via REST/App principals might come in handy for you in other situations.

As for me, this is probably the geekiest series I have written in a long time! I think I better get back to management consulting now!!

 

Thanks for reading

Paul Culmsee

www.hereticsguidebooks.com



The (currently) best way to update SharePoint document metadata using Flow

Hi all

<update>This method looks to be superseded. Please read this post and only use this method if you have trouble</update>

Anyone new to Flow, who has come from a SharePoint Designer Workflow background, will automatically assume that Flow has out of the box support for not only uploading documents to a SharePoint library, but to set metadata on it. Unfortunately this is not the case. Currently Flow has limitations with SharePoint integration that makes many common real-world scenarios difficult to achieve, including:

  • The SharePoint : Create File action provides no way to update library metadata when uploading a file, nor does it return the item ID of the newly created file
  • The SharePoint: Create Item action provides access to metadata but only works on lists
  • The SharePoint: Update Item action works on document libraries, but requires the item ID of the document to do so. Since Create File does not provide it, we have no reference to the newly created file

Basically this means it’s hard to upload a file to SharePoint via flow and then set metadata on it.

Given this is such a common scenario, I initially used a dodgy workaround. Basically the method was to:

  1. Use Create File action to upload a file
  2. Use the Get Items action to bring back the metadata for the most recently created file in the library
  3. Grab the ID from step 2
  4. Use the Update Item action to set the metadata on the recently uploaded file.

The big problem with this issue is there is no guarantee that step 2 will actually get the file from step 1. For example, if a lot of files were uploaded to a library at once, step 2 would easily grab the wrong file. The implication is this approach has data integrity concerns and does not scale.

This morning I finally found a method that is much better than my dodgy method. The basic approach is the same except step for 2. What we do now is to use the Get Items action to return the item matching a supplied file name, like so…

image

As you can see above, we are uploading a file to SharePoint and then passing the file name to a filter query of “FileLeafRef eq [Filename]” in the Get Items action.

Now behind the scenes, what blindsided me to this rather obvious approach was the web service that Flow uses to do this. You see, traditionally this would work fine with a REST call in SharePoint:

https://culmsee.sharepoint.com/_vti_bin/ListData.svc/Documents?filter=Name eq ’somefile.jpg’

Note that “Name” can be used to filter results based on file name. But when you look at the debug output of the Get Items action in Flow, you see it hitting a very different endpoint.

https://culmsee.sharepoint.com/_api/SP.APIHubConnector.GetListItems(listName=’Documents’,queryOptions=@q)?@q=%27%2524filter%3dFileLeafRef%2520eq%2520%252somefile.jpg%2527%26%25%27

(and decoded to make it a bit more readable…)

https://culmsee.sharepoint.com/_api/SP.APIHubConnector.GetListItems(listName=’Documents’,queryOptions=@q)?@q=’$filter=Name eq ‘somefile.jpg’

Now if you try this in Flow, you will get an error that column ‘Name’ does not exist. So this web service behaves differently to the SharePoint list web service that I know. Luckily there is a workaround… changing Name to FileLeafRef works Smile

This back in the Get Items action, the filter “FileLeafRef eq ‘[File name]’ will work and always return the correct ID as shown in the sequence below that adds in step 4.

image

Now note the plural in the action: “Get Items”. That means that by design, it assumes more than 1 result will be returned. Even though we are matching on a unique ID, the implication is that the data will comes back as a JSON array. Flow will pick up on this and automagically add an “Apply to Each” section around your “Update Item” action.

By the way if you are thinking that file name is not unique if there are folders in the document library, fear not because this method also works… In this case we use FileRef (which includes folder path) and compare it to Path, which is returned by the Create Item action…

Hope this helps sometime…

Paul Culmsee

www.hereticsguidebooks.com



How’s the weather? Using a public API with PowerApps (part 2)

Introduction

Hi again

This is the second half to a post that will use the OpenWeatherMap API in PowerApps. The business scenario is around performing inspections. In the first post I gave the example of a park ranger or plant operator, both conducting inspections where weather conditions can impact the level of danger or the result of the inspection. In such a scenario it makes sense to capture weather conditions when a photo is taken.

PowerApps has the ability to capture location information such as latitude and longitude, and public weather API’s generally allow you to get weather conditions for a given location. So the purpose of these posts is to show you how you can not only capture this data in PowerApps, but then send it to SharePoint in the form of metadata via Flow.

In Part 1, we got the painful stuff out of the way – that is, getting PowerApps to talk to the OpenWeather web service via a custom connector. Hopefully if you got through that part, you now have a much better understanding of the purpose of the OpenAPI specification and can see how it could be used to get PowerApps to consume many other web services. Now we are going to actually build an app that takes photos and captures weather data.

App prerequisites…

Now to get through this post, we are going to do this is to leverage a proof of concept app I built in a separate post. This app was also an inspection scenario, allowing a user to take a bunch of photos, which were then sent to SharePoint via Flow, with correctly named files. If you have not read that post, I suggest you do so now, because I am assuming you have that particular app set up and ready to go.

Go on… its cool, I will wait for you… Smile

Seriously now, don’t come back until you can do what I show below. On the left is PowerApps, taking a couple of photos, and on the right is the photos now in a SharePoint document library.

image  image

Now if you have performed the tasks in the aforementioned article, not only do you have a PowerApp that can take photos, you’ll have a connection to Flow and ready to go (yeah the pun was intended).

First up, lets recap two key parts of the original app.

1. Photo and file name…

When the camera was clicked, a photo was taken and a file name was generated for it. The code is below:

Collect(PictureList,{

        Photo: Camera1.Photo,

        ID: Concatenate(AuditNumber.Text,”-“,Text(Today(),”[$-en-US]dd:mm:yy”),”-“,Text(CountRows(PictureList)+1),”.jpg”)

} )

This code created an in-memory table (a collection named PictiureList) that, when a few photos are taken, looks like this:

image

2. Saving to Flow

The other part of the original app was saving the contents of the above collection to Flow. The Submit button has the following code…

UpdateContext( { FinalData : Concat(PictureList, ID & “|” & Photo & “#”) } );
UploadPhotostoAuditLib.Run(FinalData)

The first line takes the PictureList collection above and munges it into a giant string called FinalData. Each row is delimited by a hash “#” and each column delimited by a pipe “|”. The second line then calls the Flow and passes this data to it.

Both of these functions are about to change…

Getting the weather…

The first task is to get the weather. In part 1 we already created the custom connector to the service. Now it is time to use it in our app by adding it as a data source. From the View menu, choose Data Sources. You should see your existing data source that connects to Flow.

image  image

Click Add data source and then New connection. If you got everything right in part 1, you should see a data source called OpenWeather. Click on it, and you will be asked to enter an API key. You should have this key from part 1 (and you should understand exactly why you were asked for it at this point), so go ahead, add it here and click the Create button. If all things to go plan, you will now see OpenWeather added as a data source.

image  image  image  image

Now we are connected to the API, let’s test it by modifying the code that takes a photo. Instead of just capturing the photo and generating a file name, let’s also grab the latitude, longitude from PowerApps, call the API and collect the current temperature.

First here is the code and then I will break it down…

image

UpdateContext( { Weather: OpenAPI.GetWeather(Location.Latitude,Location.Longitude,”metric”) } );
Collect(PictureList,
{

     Photo: Camera1.Photo,

     ID: Concatenate(AuditNumber.Text,”-“,Text(Today(),”[$-en-US]dd:mm:yy”),”-“,Text(CountRows(PictureList)+1),”.jpg”),

     Latitude:Location.Latitude,

     Longitude:Location.Longitude,

     Temp:Weather.main.temp } )

 

The first line is where the weather API is called: OpenAPI.GetWeather(Location.Latitude,Location.Longitude,”metric”) . The parameters Location.Latitude and Location.Longitude come straight from PowerApps. I want my temperature in Celsius so I pass in the string “metric” as the 3rd parameter.

My API call is then wrapped into an UpdateContext() function, which enables us to save the result of the API call into a variable I have called Weather.

Now if you test the app by taking photos, you will notice a couple of things. First up, under variables, you will now see Weather listed. Drill down into it and you will see that a complex data structure is returned by the API. In the example below I drilled down to Weather->Main to find a table that includes temperature.

image

image  image

The second line of code (actually I broke it across multiple lines for readability) is the Collect function which, as its title suggests, creates collections. A collection is essentially an in-memory data table and the first parameter of Collect() is simply the name of the collection. In our example it is called PictureList.  The second second parameter is a record to insert into the collection. A record is a comma delimited set of fields and values inside curly braces. eg: { Title: “Hi”, Description: “Greetings” }. In our example, we are building a table consisting of:

  • Photo
  • File name for Photo
  • Latitude
  • Longitude
  • Temperature

The last parameter is the most interesting, because we are getting the temperature from the Weather variable. As this variable is a complex data type, we have to be quite specific about the value we want. I.e. Weather.main.temp.

Here is what the PictureList collection looks like now. If you have understood the above code, you should be able to extend it to grab other interesting weather details like wind speed and direction.

image

Getting ready for Flow…

Okay, so now let’s look at the code behind the Submit button. The change made here is to now include the additional columns from PictureList into my variable called FinalData. If this it not clear then I suggest you read this post or even Mikael Svenson’s work where I got the idea…

image

UpdateContext( { FinalData : Concat(PictureList, ID & “|” & Photo & “|” & Latitude & “|” & Longitude & “|” & Temp & “#”) } );
UploadPhotosToAuditLib.Run(FinalData)

So in case it is not clear, the first line munges each row and column from PictureList into a giant string called FinalData. Each row is delimited by a hash “#” and each column delimited by a pipe “|”. The second line then calls the Flow and passes it FinalData.

At this point, save your changes to PowerApps and publish as you are done here. Let’s now make some changes to the SharePoint document library where the photos are currently being uploaded to. We will add columns for Temperature, Latitude and Longitude and I am going to assume you know enough of SharePoint to do this and will paste a screenshot of the end in mind…

image  image

Right! Now it is time to turn our attention to Flow. The intent here is to not only upload the photos to the document library, but update metadata with the location and temperature data. Sounds easy enough right? Well remember how I said that we got rid of most of the painful stuff in part 1?

I lied…

Going with the Flow…

Now with Flow, it is easy to die from screenshot hell, so I am going to use some brevity in this section. If you played along with my pre-requisite post, you already had a flow that more or less looks like this:

  1. A PowerApps Trigger
  2. A Compose action that splits the photo via hash: @split(triggerbody()[‘ProcessPhotos_Inputs’],”#”)
  3. An Apply to each statement with a condition inside @not(empty(item()))
  4. A Compose action that grabs the file name: @split(item(),’|’)[0]
  5. A Compose action that grabs the file contents and converts it to binary: @dataUriToBinary(@split(item(),’|’)[1])
  6. A SharePoint Create File action that uploads the file to a document library

The image below illustrates the basic layout.

image

Our task is to now modify this workflow to:

  1. Handle the additional data sent from PowerApps (temperature, latitude and longitude)
  2. Update SharePoint metadata columns on the uploaded photos with this new data.

As I write these lines, Flow has very poor support for doing this. It has been acknowledged on UserVoice and I know the team are working on improvements. So the method I am going to use here is essentially a hack and I actually feel a bit dirty even suggesting it. But I do so for a couple of reasons. Firstly, it helps you understand some of the deeper capabilities of Flow and secondly, I hope this real-world scenario is reviewed by the Flow team to help them understand the implications of their design decisions and priorities.

So what is the issue? Basically the flow actions in SharePoint have some severe limitations, namely:

  • The Create File action provides no way to update library metadata when uploading a file
  • The Create Item action provides access to metadata but only works on lists
  • The Update Item action works on document libraries, but requires the item ID of the document to do so. Since Create File does not provide it, we have no reference to the newly created file
  • The Get Items function allows you to search a list/library for content, but cannot match on File Name (actually it can! I have documented a much better method here!)

So my temporary “clever” method is to:

  1. Use Create File action to upload a file
  2. Use the Get Items action to bring me back the metadata for the most recently created file in the library
  3. Grab the ID from step 2
  4. Use the Update Item action to set the metadata on the recently uploaded image.

Ugh! This method is crude and I fear what happens if a lot of flows or file activity was happening in this library and I really hope that soon the next section is soon redundant…

Okay so let’s get started. First up let’s make use of some new Flow functionality and use Scopes to make this easier. Expand the condition block and find the Compose action that extracts the file name. If you dutifully followed my pre-req article it will be called “Get File Name”. Above this, add a Scope and rename it to “Get File and Metadata”. Drag the “Get File Name” and “Get File Body” actions to it as shown below.

image  image  image

Now let’s sort out the location and temperature data. Under “Get File Body”, add a new Compose action and rename it to “Get Latitude”. In the compose function add the following:

Under “Get Latitude”, add a new Compose action and rename it to “Get Longitude”. In the compose function add the following:

Under “Get Longitude”, add a new Compose action and rename it to “Get Temperature”. In the compose function add the following:

  • @split(item(),’|’)[4]

This will result in the following:

image  image

Now click on the Get File and Metadata scope and collapse it to hide the detail of metadata extraction (now you know what a scope is for Smile)

image

So now we have our metadata, we need to apply it to SharePoint. Under the “Create File” action, add a new scope and call it “Get Item ID”. This scope is where the crazy starts…

Inside the scope, add a SharePoint – Get Items action. Enter the URL of your site collection and in the name (not URL) of your document library. In the Order By field, type in Created desc and set the Maximum Get Count to 1. Basically this action is calling a SharePoint list web service and “Created desc” says “order the results by Created Date in descending order (newest first).

Actually what you do is set Filter Query to FileLeaf eq ‘[FileName]’ as described in this later post!

Now note the plural in the action: “Get Items”. That means that by design, it assumes more than 1 result will be returned. The implication is that the data will comes back as an array. in JSON land this looks like the following:

[ { “Name”: “Value” }, { “Name”: “Value2” }, { “Name”: “Value3” } ]

and so on…

Also note that there is no option in this action to choose which fields we want to bring back, so this action will bring back a big, ugly JSON array back from SharePoint containing lots of information.

Both of these caveats mean we now have to do some data manipulation. For a start, we have to get rid of the array as many Flow actions cannot handle them as data input. Also, we are only interested in the item ID for the newly uploaded photo. All of the other stuff is just noise. So we will add 3 more flow actions that:

  1. clear out all data apart from the ID
  2. turn it from an array back to a regular JSON element
  3. extract the ID from the JSON.

For step 1, under the “Get items” action just added, add a new Data Operations – Select action. We are going to use this to select just the ID field and delete the rest. In the From textbox, choose the Value variable returned by the Get Items action. In the Map field, enter a key called “ID” and set the value to be the ID variable from the “Get Items” action.

image

For step 2, under the “Select” action, add a Data Operations – Join action. This action allows you to munge an array into a string using a delimiter – much like what we did in PowerApps to send data to Flow. Set the From text box to be the output of the Select action. The “Join with” delimiter can actually be anything, as the array will always have 1 item. Why? In the Get Items action above, we set the Maximum Get Count to 1. We will always get back a single item array.

image

The net effect of this step will be the removal of the array. I.e., from:

[ { “ID”: 48 } ]

to

{ “ID”:48 }

For step 3, under the “Join” action, add a Data Operations – Parse JSON action. This action will process the JSON file and each element found will be available to subsequent actions. The easiest way to understand this action is to just do it and see the effect. First, set the Content textbox to the output from the Join action.

image

Now we need to tell this action which elements that we are interested in. We already know that we only have 1 variable called ID because of the Select action we set up earlier that has stripped everything else out. So to tell this action we are expecting an ID, click the “use sample payload…” link and paste some sample JSON in our expected format…

{

    “ID”:48

}

If all goes to plan, a Schema has been generated based on that sample data that will now allow us to grab the actual ID value.

image  image

Okay, so we are done with the Get Item ID scope, so collapse it as follows…

image

Finally, under the “Get Item ID” scope, add a SharePoint – Update Item action. Add the URL of your site collection and then specify the document library where the photos were uploaded to. If this has worked, the additional metadata columns should now be visible as shown in the red box below. Now set the specific item we want to update by setting the ID parameter to the ID variable from the Parse JSON step.

image

Now assign the metadata to the library columns. Set Latitude to the output variable from the Get Latitude step, Longitude to the output variable from the Get Longitude step and Temperature to the output variable from the Get Temperature step as shown below.

image

Now save your flow and cross all fingers and toes…

Testing and conclusion!

Return to PowerApps (in the browser or on your mobile device – not the PowerApps studio app). Enter an audit number and take some photos… Wohoo! Here they are in the library along with metadata. Looks like I need to put on a jacket when I step outside Smile

image   image

So taking a step back, we have managed to achieve quite a lot here.

  1. We have wired up a public web service to PowerApps
  2. We have used PowerApps built-in location data to load weather data each time a photo has been taken
  3. We have used Flow to push this data into SharePoint and included the location and weather data as parameters.

Now on reflection there are a couple of massive issues that really prevent this from living up to its Citizen Developer potential.

  1. I had to use a 3rd party service to generate my OpenAPI file and it was not 100%. Why can’t Microsoft provide this service?
  2. Flow’s poor support for common SharePoint scenarios meant I had to use (non) clever workarounds to achieve my objectives.

Both of these issue were resolvable, which is a good thing, but I think the solutions take this out of the realm of most citizen developers. I had to learn too much JSON, too much Swagger/OpenAPI and delve deep into Flow.

In saying all that, I think Flow is the most immature piece of the puzzle at this stage. The lack of decent SharePoint support is definitely one where if I were a program manager, I would have pushed up the release schedule to address. It currently feels like the developer of the SharePoint actions has never used SharePoint on a day to day basis, and dutifully implemented the web services without lived experience of the typical usage scenarios.

For other citizen developers, I’d certainly be interested in how you went with your own version and variations of this example, so please let me know how you go.

And for Microsoft PowerApps/Flow product team members who (I hope) are reading this, I think you are building something great here. I hope this material is useful to you as well.

 

Thanks for reading

 

Paul Culmsee

www.hereticsguidebooks.com



A Clever-workaround for Saving Photos to SharePoint from PowerApps

At the time of writing, a common request for PowerApps is to be able to able to upload photos to SharePoint. It makes perfect sense, especially now that its really easy to make a PowerApp that is bound to a SharePoint list. Sadly, although Microsoft have long acknowledged the need in the PowerUsers forum, a solution has not been forthcoming.

<update>I now use a Flow-based method for photos that I documented in this video. I only use this method in complex scenarios</update>

I have looked at the various workarounds, such as using the OneDrive connector or a custom web API, but these for me were fiddly. Thanks to ideas from John Liu, I’ve come up with a method that is more flexible and less fiddly to implement, provided you are okay with a bit of PowerShell, and (hopefully) with PnP PowerShell. One advantage to the method is that it handles an entire gallery of photos in a single transaction, rather than just a single photo at a time.

Now in the old days I would have meticulously planned out a multi-part series of posts related to a topic like this, because I have to pull together quite a lot of conceptual threads into a single solution. But since the pace of change in the world of Office365 is so rapid, my solution may be out of date by the time I publish it. So instead I offer a single summary post of my solution and leave the rest to you to figure out.  Sorry followers, its just too hard to do epic multi-part articles these days – times have changed.

What you need

  1. An understanding of JSON and basic idea of web services
  2. An azure subscription
  3. Access to Azure functions
  4. The PnP Powershell cmdlets
  5. A Swagger file (don’t worry if this makes no sense now)
  6. To be signed up to PowerApps

 How we are going to solve this…

In a nutshell, we will create an Azure function, using PowerShell to receive photos from PowerApps and uploads them to a SharePoint library. Here is my conceptual diagram that I spent hours and hours drawing…

Snapshot

To do this we will need to do a few things.

  1. Customise PowerApps to store photo data in the way we need
  2. Create and configure our Azure function
  3. Write and test the PowerShell code to upload to SharePoint
  4. Create a Swagger file so that PowerApps can talk to our Azure function
  5. Create a custom PowerApps connection/datasource use the Azure function
  6. Test successfully and bask in the glory of your awesomeness

Step 1: Customise PowerApps to store photo data in the way we need

Let’s set up a basic proof of concept PowerApp. We will add a camera control to take photos, a picture gallery to view the photos and a button to submit the photos to SharePoint. I’ll use the PowerApps desktop client rather than the web page for this task and create a blank app using the Phone Layout.

image

From the Insert menu, add a Camera control from the Media dropdown to add it to the screen. Leave it up near the top…

image

From the Insert Menu, add a Gallery control. For my demo I will use the vertical gallery. Move it down below the camera control so it looks like the second image below.

image  image

From the Insert Menu, add two buttons below the gallery. Set the text property on one to “Submit” and the other to “Clear”. I realise the resulting layout will not win any design awards but just go with it. Use the picture below to guide you.

image    image

Now let’s wire up some magic. Firstly, we will set it up so clicking on the camera control will take a photo, and save it to PowerApps storage. To do this we will use the Collect function. Assuming your Camera control is called “Camera1”, select it , and set the OnSelect property to:

Collect(PictureList,Camera1.Photo)

image

Now when a photo is taken, it is added to an in-memory PowerApps data-source called PictureList. To see this in action, preview the PowerApp and click the camera control a couple of times. Exit the preview and choose “Collections” from the left hand menu. You will now see the PictureList collection with the photos you just took, stored in a field called Url. The reason it is called URL and not “Photo” will become clear later).

image

Now let’s wire up the clear button to clear out this collection. Choose the button labelled “Clear” and set its OnSelect property to:

Clear(PictureList)

image

If you preview the app and click this button, you will see that the collection is now empty of pictures.

The next step is to wire up the Gallery to the PictureList collection so that you can see the photos being taken. To do this, select the gallery control and set the Items property to PictureList as shown below. Preview this and you should be able to take a set of photos, see them added to the gallery and be able to clear the gallery via the button.

image

image

Now we get to a task that will not necessarily make sense until later. We need to massage the PictureList collection to get it into the right format to send to SharePoint. For example, each photo needs a filename, and in a real-world scenario, we would likely further customise the gallery to capture additional information about each photo. For this post I will not do this, but I want to show you how you can manipulate data structures in PowerApps. To do this, we are going to now wire up some logic to the “Submit” button. First I will give you the code before I explain it.

Clear(SubmitData);
ForAll(PictureList,Collect(SubmitData, { filename: "a file.jpg", filebody: Url }))

image

In PowerApps, it is common to add multiple statements to controls, separated by a semicolon. Thus, the first line above initialises a new Collection I have called “SubmitData”. If this collection already had data in it, the Clear function will wipe it out. The second line uses two functions, ForAll and the previously introduced Collect. ForAll([collection],[formula]) will iterate through [collection] and perform tasks specified in [formula]. In our case we are adding records to the SubmitData collection. Each record consists of two fields and is in JSON format – hence the curly braces. The first field is called filename and the second is called filebody. In my example the filename is a fixed string, but filebody grabs the Url field from the current item in PictureList.

To see the effect, run the app, click submit and then re-examine the collections. Now you will see two collections listed – the original one that captures the photos from the camera (PictureList), and the one called SubmitData that now has a field for filename and a field called filebody with the photo. I realise that setting a static filename called “a file.jpg” is not particularly useful to anybody, and I will address this a little later, the point is we now have the data in the format we need.

image

By the way, behind the scenes, PowerApps stores the photo in the Data URI scheme. This is essentially a Base64 encoded version of the image with a descriptor at the start that is included in HTML. When you think about it, this makes sense in some situations because it reduces the number of HTTP round trips between browser and server. For example here is a small image encoded and embedded direct in HTML using the technique.

<img src="data:image/png;base64,iVBORw0KGgoAAA
ANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4
//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU
5ErkJggg==" alt="Red dot" />

The implication of this format is when PowerApps talks to our Azure function, it will send this sort of JSON…

[ {  "filename": "boo.jpg",
"filebody": "data:image/jpeg;base64,/9j/4AAQSkZJR [ snip heaps of Base64 ] T//Z" },
{  "filename": "boo3.jpg",
"filebody": "data:image/jpeg;base64,/9j/TwBAQMEBA [ snip heaps of Base64 ] m22I" } ]

In the next section we will set up an Azure Function and write the code to handle the above format, so save the app in its current state and give it a nice name. We are done with PowerApps for now…

2. Create and Configure Azure Function

Next we are going to create an Azure function. This is the bit that is likely new knowledge for many readers. You can read all about them on their Azure page, but my quick explanation is that they allow you to take a script or small piece of code and turn it into a fully fledged webservice. As you will soon see, this is very useful indeed (as well as very cost effective).

Now like many IT Pros, I am a PowerShell hacker and I have been using the PowerShell PnP libraries for all sorts of administrative purposes for quite some time. In fact if you are administering an Office365 tenant and you are not using PnP, then I can honestly say you are missing out on some amazing time-saving toolsvand you owe it to yourself to skill-up in this area. Of course, I realise that many readers will not be familiar with PowerShell, let alone PnP, and I expect some readers have not done much coding at all. Luckily the code we are going to use is just a few lines and I think I can sufficiently explain it.

But we are getting ahead of ourselves, let’s create the Azure function and then revisit PowerShell. Assuming you have an Azure subscription, visit functions.azure.com and log in. If not, sign up for the free account and then create a function app to host the function. I called mine MyFunctionsDemo but yours will have to be something different. This will take minute or two to complete and you will be redirected to the Azure functions portal.

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Once the web application to host your functions is created, Click the + next to the Functions button to create a new function. PowerShell is still in preview, so you have to click the option to create a custom function. On the next screen, in the Language dropdown, choose PowerShell.

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Our function is going to be triggered from PowerApps when a user clicks the submit button. PowerApps will make a HTTP request so this is a HttpTrigger scenario. Click the HttpTrigger-PowerShell template, give it a name (I called mine PhotoSendSP) and click the Create button. If all goes to plan you will be presented with a screen with some basic PowerShell code… essentially a “Hello World” web service.

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Let’s test this newly minted Azure function before we customise it. If you look to the right of the screen above, you will see a “Test” vertical label. Click it and you will be presented with a screen that allows you to craft some data to send to your shiny new function. You can see that the test is going to be a HTTP POST by default. As you can see below, there is a basic JSON entry with a single name/value pair “name”: “Azure”. Change the Azure string to something else and then click the Run button. The result will be displayed below the JSON as shown below.

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Now let’s take a quick look at the PowerShell code provided to you by default. Only lines 2, 3 and 11 matter for our purposes. What lines 2 and 3 show is that all of the details that are posted to this webservice are stored in a variable called $req. Line 2 converts this to JSON format and stores that in a variable called $requestbody. Line 3 then asks $requestbody for the value of “name”, which is you look in the screenshots above are what you set in the test. Line 11 then outputs this line to a variable called $res, which is the response back to the caller of this webservice. In this case you can see it returns “Hello “ with $name appended to it.

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Now that we have seen the PowerShell code, let’s now update it with code to receive data from PowerApps and send it to SharePoint.

3. Write and test the PowerShell code that uploads to SharePoint

If you recall with PowerApps, the data we are sending to SharePoint is one or more photos. The data will look like this…

[ {  "filename": "boo.jpg",
"filebody": "data:image/jpeg;base64,/9j/4AAQSkZJR [ snip heaps of Base64 ] T//Z" },
{  "filename": "boo3.jpg",
"filebody": "data:image/jpeg;base64,/9j/TwBDAQMEBAUEBQ  m22I" } ]

In addition, for the purposes of keeping things simple, I am going to hard code various things like the document library to save the files to and not worry about exception handling. Below is my sample code with annotations at the end…

1.  Import-Module "D:\home\site\wwwroot\modules\SharePointPnPPowerShellOnline\2.15.1705.0\SharePointPnPPowerShellOnline.psd1" -Global
2.  $requestBody = Get-Content $req -Raw | ConvertFrom-Json
3.  $username = "paul@tenant.onmicrosoft.com"
4.  $password = $env:PW;
5.  $siteUrl = "https://tenant.sharepoint.com"
6.  $secpasswd = ConvertTo-SecureString $password -AsPlainText -Force
7.  $creds = New-Object System.Management.Automation.PSCredential ($username, $secpasswd)
8.  Connect-PnPOnline -url $siteUrl -Credentials $creds
9.  $ctx = get-pnpcontext
10. $doclib = $ctx.Web.Lists.GetByTitle("Documents")
11. ForEach ($item in $requestbody)
12. {
13.    $filename = $item.filename
14.    $rawfiledata = $item.filebody
15.    $rawfiledata = $rawfiledata -replace 'data:image/jpeg;base64,', ''
16.    $bytes = [System.Convert]::FromBase64String($rawfiledata)
17.    # uses comma notation related to .net reflection http://piers7.blogspot.com.au/2010/03/3-powershell-array-gotchas.html
18.    $memoryStream = New-Object System.IO.MemoryStream (,$bytes)
19.    $FileCreationInfo = New-Object Microsoft.SharePoint.Client.FileCreationInformation
20.    $FileCreationInfo.Overwrite = $true
21.    $FileCreationInfo.ContentStream = $memoryStream
22.    $FileCreationInfo.URL = $filename
23.    $Upload = $doclib.RootFolder.Files.Add($FileCreationInfo)
24.    $ctx.Load($Upload)
25.    $ctx.ExecuteQuery()
26. }

 

  • Line 1 loads the PnP PowerShell module. Without this, commands like Connect-PnPOnline and Get-PnPContext will not work. I’ll show how this is done after explaining the rest of the code.
  • Lines 3-7 are all about connecting to my SharePoint online tenant. Line 4 contains a variable called $env:PW. The idea here is to avoid passwords being stored in the code in clear text. The password is instead is pulled from an environment variable that I will show later.
  • Lines 7-9 connect to a site collection and then connect to the default document library within it.
  • Line 10 looks at the data sent from PowerApps and loops around to process for each image/filename pair.
  • Lines 13-18 grabs the file name and file data. It converts the file data into a memorystream, which is a way to represent a file in memory.
  • Line 19-25 then uploads the in-memory image to the document library in SharePoint, based on the filename provided. (Note: any PnP gurus wondering why I did not use Add-PnPFile, it was because this cmdlet did not properly handle the memorystream and the images were not proper binary and always broken.)

So now that we have seen the code, lets sort out some final configuration to make this all work. A lot of the next section I learnt from John Liu and watching the excellent Office Patterns and Practices Special Interest Group webinar he recently did with my all-time SharePoint hero, Vesa Juvonen.

Installing PnP PowerShell Components

First up, none of this will work without the PnP PowerShell module deployed to the Azure Function App. The easiest way to do this is to install the PnP PowerShell cmdlets locally and then copy the entire installation up to the Azure function environment. John Liu explains this in the aforementioned webinar but in summary, the easiest way to do this is to use the Kudu tool that comes bolted onto Azure functions. You can find it by clicking the Azure function name (“MyFunctionDemo” in my case) and choosing the “Platform Features” menu. From here you will find Kudu hiding under the Development Tools section. When the Kudu tab loads, click the Debug console menu and create a CMD or PowerShell console (it doesn’t matter which)

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We are going to use this console to copy up the PnP PowerShell components. You can ignore the debug console and focus on the top half of the screen. This is showing you the top level folder structure for the Azure function application. Click on site and then wwwroot folders. This is the folder where all of your functions are stored (you will see a folder matching the name of the module we made in step 2). What we will do is install the PnP modules at this level, so it can be used for other functions that you are sure to develop Smile.

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So click the + icon to create a folder here and call it Modules. From here, drag and drop the PnP PowerShell install location to this folder. In my case C:\Program Files\WindowsPowerShell\Modules\SharePointPnPPowerShellOnline\2.15.1705.0. I copied the SharePointPnPPowerShellOnline\2.15.1705.0 folder and all of its content here as I want to be able to maintain multiple versions of PnP as I develop functions over time.

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Now that you have done this, the first line of the PowerShell script will make sense. Make sure you update the version number in the Import-Mobile command to the version of PnP you uploaded.

Import-Module "D:\home\site\wwwroot\modules\SharePointPnPPowerShellOnline\2.15.1705.0\SharePointPnPPowerShellOnline.psd1"

Handling passwords

The next thing we have to do is address the issue of passwords. This is where the $env:PW comes in on line 4 of my code. You see, when you set up Azure functions application, you can create your own settings that can drive the behaviour of your functions. In this case, we have made an environment variable called PW which we will store the password to access this site collection. This hides clear text passwords from code, but unfortunately it is a security by obscurity scenario, since anyone with access to the Azure function can review the environment variable and retrieve it. If I get time, I will revisit this via App Only Authentication and see how I go. I suspect though that this problem will get “properly” solved when Azure functions support using the Azure Key Vault.

In any event, you will find this under the Applications Settings link in the Platform Features tab. Scroll down until you find the “App Settings” section and add your password in as shown in the second image below.

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Testing it out…

Right! At this point, we have all the plumbing done. Let’s test to see how it goes. First we need to create a JSON file in the required format that I explained earlier (the array of filename and filebody pairs). I crafted these by hand in notepad as they are pretty simple. To remind you the format was:

[ {  "filename": "boo.jpg",
"filebody": "data:image/jpeg;base64,/9j/4AAQSkZJR [ snip heaps of Base64 ] T//Z" },
{  "filename": "boo3.jpg",
"filebody": "data:image/jpeg;base64,/9j/TwBDAQMEB [ snip heaps of Base64 ] m22I" } ]

To generate the filebody elements, I used the covers of my two books (they are awesome – buy them!) and called them HG2BP and HG2M respectively. To create the base 64 encoded images in the Data URI scheme, I went to https://www.base64-image.de and generated the encoded versions. If you are lazy and want to use a pre-prepared file, just download the one I used for testing.

h2bph2m image

To test it, all we need to do is click the right hand Test link and paste the JSON into it. Click the Run button and hope for the best! As you can see in my example below, the web service returned a 200 status which means hunky dory, and the logs showed the script executing successfully.

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Checking my document library and they are there… wohoo!!

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So basically we have a lot of the bits in place. We have proven that our Azure function can take a JSON file with encoded images, process that file and then save it to a SharePoint document library. You might be thinking that all we need to do now is to wire up PowerApps to this function? Yeah, so did I too, but little did I realise the pain I was about to endure…

4. Create a Swagger file so that PowerApps can talk to our Azure function

Now we come to the most painful part of this whole saga. We need to describe our Azure function using a standard called Swagger (or OpenAPI). This provides important metadata so that PowerApps can make it easy for users to consume. This will make sense soon enough, but first we have to create it, which is a royal pain in the ass. I found the online documentation for swagger to be lacking and it took me a while to understand enough of the format to get it working.

So first up to make things simpler, let’s reduce some of the complexity. Our Azure function is a simple HTTP post. We have not defined any other type of requests, so lets make this formal as it will generate a much less ugly Swagger definition. Expand your function and choose the “Integrate” option. On the next screen, under Triggers, you will find a drop down with a label “Allowed HTTP methods”. Change the default value to “Selected methods” and then untick all HTTP methods except for POST. Click Save.

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Now click back to your function app, and choose “API Definition” from the top menu. This will take you to the screen where you create/define your Swagger file.

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On the initial screen, set your API definition source to function if asked, and you should see a screen that looks somewhat like this…

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Click the Generate API definition template button as suggested by the comment in the code box in the middle. This will generate a swagger file and on the right side of the screen, the file has will be used to generate a summary of your API. You can see the Url of your azure app, some information about an API key (which we will deal with later) and below that, the PhotoSendSP function exposed as a webservice (/api/PhotoSendSP).

image

Now at this point you are probably thinking “okay so its unfamiliar, but this is pretty easy”, and you would be right. Where things got nightmarish for me was working out how to understand and customise the swagger file as the template is currently incomplete. All it has done is defined our function (note the paths section in the above screenshot  – can you see all those empty square brackets? that’s what you need to now fill in).

For the sake of brevity, I am not going to describe the ins and outs of this format (and I don’t fully know it yet anyway!). What I can tell you is that getting this right is a painful and time-consuming combination of trial and error, reading the swagger spec and testing in PowerApps. Let’s hope my hints here save you some frustration.

The first step is we need to create a definition for the format of data that our Azure function accepts as input. If you look closely above, you will see a section called definitions. Paste the following into the section so it looks like the screenshot below. Note: If you see any symbol apart from a benign warning message next to the “Photos:” line, then you do not have it right!.

definitions:
   Photos:
      type: object
      required:
         - filename
         - filebody
      properties:
         filename:
            type: string
            example: image.jpg
         filebody:
            type: string

image

So what we have defined here is an object called Photos which consists of two required properties, filename and filebody. Both are assumed to be string format, and filename also has an example to illustrate what is expected. Depending on how this swagger file is consumed by another application that supports swagger, one can imagine that example showing up on online help or intellisense when our function is being called.

Now lets make use of this definition.  Paste this into the parameters and description sections. Note the “schema:” section. Here we have told the swagger file that our function is expecting an array of objects based on the Photos definition that we created earlier.

parameters:
  - name: photocollection
    in: body
    description: “The encoded files”
    required: true
    schema:
       type: array
       items:
          $ref: '#/definitions/Photos'
description: "A collection of photos and filenames"

image

Finally, let’s finish off by defining that our Azure function consumes and produces its data in JSON format. Although our sample code is not producing anything back to PowerApps, you can imagine situations where we might do something like send back a JSON array of all of the SharePoint URL’s of each photo.

produces:
- application/json
consumes:
- application/json

image

Okay, so we are all set. Now to be clear, there is a lot more to Swagger, especially if you wanted to call our function from flow, but for now this is enough. Click the Save button, and then click the button “Export to PowerApps + Flow”. You will be presented with a new panel that explains the process we are about to do. Feel free to read it, but the key step is to download the swagger file we just created.

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Okay, so if you have made it this far, you have a swagger JSON file and you are in the home stretch. Let’s now head back to PowerApps!

5. Create a custom PowerApps connection/datasource to use the Azure function

Back in PowerApps, we need to make a new custom connection to our Azure function. Click the Connections menu item and you will be redirected to web,powerapps.com. Click “Manage Custom Connections” and then click “Create a custom connector”. This will take you to a wizard.

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The first step is to upload the swagger file you created in step 4 and before you do anything else, rename your connector to something short and sweet, as this will make it easier when displayed in the PowerApps list of connections.

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Scroll to the bottom the of page and click the “Continue” button. Now you are presented with some security options about your connector. For context, the default settings for the PowerShell azure function template we chose in step 2 was to use an API key, so you can leave all of the defaults here, although I like to add the more meaningful “API Key” (this will make sense soon). Click Continue

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PowerApps has now processed the swagger file and found the PhotoSendSP POST action we defined. It has also pulled some of the data from the swagger file to prepopulate some fields. Note this screen has some UI problems – you need to hover your cursor over the forms in the middle of the screen to see the scrollbar, so there is more to edit than what you initially see…

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For now, do not enter anything into the summary field and scroll down to look at some of the other settings. The Visibility setting does not really matter for PowerApps, but remember that other online services can call our function. This visibility stuff relates more to Microsoft Flow, so you can ignore it for now. Scroll further down and you will see how our swagger schema has been processed by PowerApps. You can explore this but I suggest leaving it well alone. Below I have used all my MSPaint skills to make a montage to show how this relates to your Swagger file…

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Finally, click Create Connector to wire it up. If all has gone to plan, you will see something resembling the following in the list of custom connectors in PowerApps. If you get this far, congratulations! You are almost there!

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6. Test successfully and bask in the glory of your awesomeness

Now that you have a custom connection, let’s try it out. Open your PowerApp that you created in step 1. From the Content menu, click Data sources, click Add Datasource and then click New Connection. Scroll through the list of connections until you find the one you created in step 5. Click on it and you will be prompted for an API key (now you see why I added that friendly label during step 5).

image  image  image

Where to find this key? Well, it turns out that it was automagically generated for you when you first created your function! Go back to Azure functions portal and find your function. From the function sub menus, click Manage and you will be presented with a “Functions Keys” section with a default key listed. Copy this to the clipboard, and paste it back into the PowerApps API Key text box and click the Create button. Your datasource that connects to your Azure function is now configured in PowerApps!! (yay!).

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Now way back in step 1 (gosh it seems like such a long time ago), we created a button labelled Submit, with the following formula.

Clear(SubmitData);
ForAll(PictureList,Collect(SubmitData, { filename: "a file.jpg", filebody: Url }))

The problem we are going to have is that all files submitted to the webservice will be called “a file.jpg” as I hardcoded the filename parameter for simplicity. Now if I fully developed this app, I would add a textbox to the gallery so that each photo has to be named prior to being able to submit to SharePoint. I am not going to do that here as this post is already too long, so instead I will use a trick I saw here to create a random two letter filename. I know it is not truly unique, but for our demo will suffice.

Here is the formula in all its ugliness.

Concatenate(Text( Now(), DateTimeFormat.LongDate ),Mid("0123456789ABCDEFGHIJKLMNOPQRTSTIUVWXYZ", 1 + RoundDown(Rand() * 36, 0), 1),Mid("0123456789ABCDEFGHIJKLMNOPQRTSTIUVWXYZ", 1 + RoundDown(Rand() * 36, 0), 1),".jpg"), filebody: Url } ) )

Yeah I know… let me break it down for you…

  • Text( Now(), DateTimeFormat.LongDate ) produces a string containing todays date
  • Mid(“0123456789ABCDEFGHIJKLMNOPQRTSTIUVWXYZ”, 1 + RoundDown(Rand() * 36, 0), 1) – selects a random letter/number from the string
  • Concatenate takes the above date, random letters and adds “.jpg” to it.

PowerApps does allow for line breaks in code, so it looks less ugly…

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Let’s quickly test this before the final step of sending it off to SharePoint. Preview the app, take some photos and then examine the collections. As you can see, the SubmitData collection now has unique filenames assigned (By the way, yes I took these in a car and no, I was not driving at the time! 🙂

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We are now ready for the final step. We need to call the Azure function! Smile

Go back to your submit button and add the following code to the end of the existing code, taking into account the name you gave to your connection/datasource. You should find that PowerApps uses intellisense to help you add the line because it has a lot of metadata from the swagger file.

'myfunctionsdemo.azurewebsites.net'.apiPhotoSendSPpost(SubmitData)

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Important! Before we go any further, I strongly suggest you use the PowerApps web based authoring environment and not the desktop application. I have seen a problem where the desktop application does not encode images using the Data URI format, whereas the web based tool (and PowerApps clients on android and IOS) work fine.

So log into PowerApps on the web, open your app, preview it and cross your fingers! (If you want to be clever, go back to your function in Azure and keep and eye on the logs Smile

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As the above screen shows, things are looking good. Let’s check the SharePoint document library that the script uploads to… YEAH BABY!! We have our photos!!!

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Conclusion

Now you finally get to bask in your awesomeness. If you survived all this plumbing and have gotten this working then congratulations! you are well on your way to becoming a PowerApps, PowerShell, PnP (and flow) guru. This means you can now enhance your apps in all sorts of ways. For the non-developers who got this far, you can truly call yourself a citizen developer and design all sorts of innovative solutions via these techniques.

Even though a lot of this stuff is fiddly (especially that god-awful swagger crap), once you have gone through it a couple of times, and understand the intent of the components we have used, this is actually quite an easy solution to put together. I also found the Azure function side of things in particular, really easy to debug and see what was going on.

In terms of where we could take this, there are several avenues that I can immediately think of, but the possibilities are endless.

  • We could update the PowerShell code so it takes the destination document library as a parameter. We would need to update a new Swagger definition and then update our datasource in PowerApps, but that is not too hard a task once you have the basics working.
  • Using the same method, we could design a much more sophisticated form and capture lots of useful metadata with the pictures, and get them into SharePoint as metadata on the picture.
  • We could add in a lot more error handling into the script and return much better detail to PowerApps, such as detailed failure information.
  • Similarly, we could return detailed information to PowerApps to make the app richer. For example, we could generate unique filenames in our PowerShell function rather than PowerApps and return those names (and the URL to the image) in the reply to the HTTP Post, which would enable PowerApps to display images inline.
  • We could also take advantage of recent PowerApps enhancements and use local caching. I.e, when an internet connection is available, call the API, but if not, save to local storage and call the API once a connection is available.
  • We could not only upload images, but update lists and any other combination of SharePoint functions supported by PnP.

I hope that this post has helped you to better understand how these components hang together and I look forward to your feedback and how you have adopted/adapted and enhanced the ideas presented here.

 

Thanks for reading

 

Paul Culmsee

www.hereticsguidebooks.com

 



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