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Blog about the Power Platform

Month: September 2019

Update: Create a file in SharePoint with Base64string in Flow! – Flow

Dear readers of my blog, to close the week I will quickly post an experience I had this week. This week I received a request from a customer to upload an image on SharePoint by using PowerApps. There are plenty of blog posts on the internet about how to implement this. So I won’t explain the whole solution, but I would like to point out to you a curious thing that I have discovered.

The Problem

When we use a custom connector for Flow and PowerApps we could capture this Base64 by using the action ‘When an HTTP request is received’. In the past, it was enough to give this Base64 to the action ‘Create File’. However, this week I ran into an error message here.

The input you get without creating the object. Then the step automatically creates content-type: image/jpeg. Here I got an error message.

When we gave the Base64 string as the input to the action, the ‘File Content’ property was automatically assigned ‘application/octet-stream’ as Content-Type. As a result, my images were not visible in SharePoint. And this is where the search for a workable solution started.

The Solution

Thanks to a colleague we were able to find a solution to this problem internally. The solution is very simple, but not really obvious. That’s why I wanted to share this with you quickly.

The compose step where we’re going to declare the object.

The action now expects an object, instead of a Base64 string. We declare this object in a Compose action. Entering the Content-Type of the file wasn’t rocket science either. As we got this from the ‘ When an HTTP request is received’, we could get it from the body of the request. We gave this value in the ‘Compose’ action. The code looks like this:





Then we give the output of the compose step to the ‘Create File’ action.

Now we can see our images or documents in SharePoint! As a control, I’ll give you the output of the action after it’s been run. The output looks like this:

Note: It is important that the Content-Type is no longer equal to “application/octet-stream”.

Important! This way of working is accompanied by a custom connector that we wrote for PowerApps and Flow to forward this document. How to implement this can be seen in the blog below.


If you don’t use a custom connector for Flow and PowerApps, there is a hack I discovered this week. Our customer did not have premium licenses for Flow/PowerApps so I was allowed to look for an alternative. Thanks to this blog post I was able to avoid this: http://johnliu.net/blog/2019/4/flowninja-hack-87-lock-microsoft-flow-powerapps-trigger-to-upload-images-to-sharepoint-with-ease. Thumb up for this post, it helped me a lot.

I hope you have an answer now if you also run on this error message! Have a good weekend and see you at the next post!

Control Site Creation in SharePoint with the PowerPlatform. – Flow & PowerApps

Is there a need to give end-users the power to create a team/communication site on SharePoint? Keep everything under control with PowerApps and Flow. In this blog, I will work out a simple example, feel free to make this even more challenging by trying the extras that will be at the bottom of the page.

In order to work out this example, we need 3 technologies:
– PowerApps (as the central entry point for the variable data)
– Flow (creating the site + securing a widget growth of sites)
– SharePoint (site creation)


Go to www.powerapps.com and log in with your account. Then choose the option “Canvas App from Blank”. We choose this option because we are not going to use any data sources in this solution. Also, we will only use one page, with only a few elements. Automatically generating 3 pages would be a waste of time.

In PowerApps we make a simple PowerApp with a title, 3 labels, and 3 TextInputs. These will then give the end-users the possibility to enter the variables to feed the Flow.

Little tip:
Change the property “Mode” to MultiLine. This allows end-users to enter the description of the site easily and conveniently.


Before we can finish the PowerApp, we first have to assemble our Flow. To do this we go to https://emea.flow.microsoft.com/en-us/. Here we choose “Instant – from blank”, then we select the PowerApps trigger.

The steps

In the first step of our flow, we will start an approval. This approval will allow us to get an overview of the requests to create a site in SharePoint. The approval will warn us if the end-user wants to create a site. Then we can give our consent if the site can be created, or not. Approval also gives us the opportunity to give comments to the end-user, informing him why we don’t want to create the site.

The next step will be waiting for our answer. Since our response can be positive or negative, we’re going to put our response in a condition.

If we accept/refuse the request, we can keep the end-user informed by email.

As the last step in our flow, we are going to create a site. This is possible if you enter the parameters as shown in the image below.


Last but not least, we’ll stop one more action behind our button. We go to the “OnSelect” property of the button. Here we will feed our flow with the input fields of our PowerApp.

Once we have selected our flow in PowerApps, we can supplement it with our input fields. The fields that flow needs are the following:

  • ApproverToEmail: “”
  • ResultFollowUpToEmail: User().Email => This formula will put in the email of the user who is signed in
  • Startanapproval_Title: TextInputSite.Text
  • Startanapproval_Details: TextInputDescription.Text
  • CreateSite_Body: TextInputAlias.Text

The end

I hope this blog was helpful to you. The extra “challenges” I mentioned in the beginning I will list below:

  • A challenge can be to make PowerApp visually more attractive.
  • In addition, you can also look to do extra things with Flow. For example: expand the mail with extra information, add extra things to the SharePoint site via Flow (Document Libraries, Folders,…). There will certainly be posts about this on this blog.

Thanks for reading this blog, see you at the next post!

Need to add many folders to a Document Library? Consider using Flow! – Flow

Hello everybody, sorry for the long absence but I was on vacation. Here we are again with a short but easy to use tip for Flow users who work a lot with SharePoint. This tip will make your flow a lot shorter, because you don’t have to copy all the steps. The simple answer to this problem will be explained in this blogpost.

The Problem

We are asked to add 10 folders to a document library on a SharePoint site. You can use this tip for one-time use to adjust a SharePoint site, but you can also automate this to apply it to multiple sites.

The Solution

First, create a list of all folders who needs to be provided in the document library. We do this by using the action ‘Initialize variable’.

Then we provide a loop that will cover all the elements in the list. For each element a folder will be provided. Instead of the black square, you place the name of the document library. The flow will create the different folders in this location using the ‘Current Item’ which is given as ServerRelativeUrl in the Body of the POST HTTP request.

The Code in the Uri:


The Code in the Body:

“__metadata”: { “type”: ‘SP.Folder’ },

Now Flow will take care of the several folders in the document library. This was again a short tip but no less handy! Next week there will be a new blog post, stay tuned…

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