How to Check If a Microsoft Form Contains an Attachment

[QuintonR]

I thought it would help out our Power Automate community if I included how to write a condition to check if a Microsoft Form response contains an attachment. 

Step 1: Add the trigger "When a new response is submitted" and select your form.

Step 2: Get response details. In the Response Id, select "Response Id." 

Step 3: Create a new Control and select Condition.

Step 4: In the box on the left, select Dynamic Content, then choose your question where users submit a file. In this example, the question is "Attach File (If applicable)."

Step 5: Select "contains" in the middle box.

Step 6: In the box on the right-hand side, type a single opening bracket (Don't include quotation marks) 

Step 7: Add whatever actions you want in the "If yes" and "If no" fields. 

Here is why this works:

If your question asks the user to upload a file, and the user doesn't upload a file, the raw output looks like this:

If your question asks the user to upload a file, and the user does upload a file, the raw output looks like this:

In this example, the "[" character appears only when the user submits an attachment. Therefore, if there's no "[" character, there's no attachment. If there is a "[" character, there's an attachment.

Final Notes

It's important to note that I don't have Microsoft Documentation to back up this theory. It's just something I've discovered, tested, and used on my end. It works reliably for me, but whether or not this example follows best practice, I can't say. 

[Expiscornovus · Accepted solution]

Hi @QuintonR,

The '[]' brackets are used for an array. In this case this is an array for details of one or more files.

You can check if the user did not upload any files with either a length (is equal to 0) or empty (is equal to true) function in an expression.

Below is an example with length.

empty(outputs('Get_response_details')?['body/r6c7d2160a35c4862a6b8861cccb9abee'])

is equal to 0

[QuintonR]

@Expiscornovus Thanks for your help. While I couldn't successfully execute the flow using the empty (is equal to true) function, I could successfully successfully the length (is equal to 0) expression.

You have to think a little bit harder with the length expression as it currently is shown because it's saying, "If there aren't attachments, " followed by an "If yes" or "If no," but it works out! 

Thank you for your insight into this; it was beneficial! 

[nverardi]

Hello,

I have also tried it with both commands.

With "empty" the flow always goes the "yes" way regardless of whether a file is attached or not.

With the "length" command is equal to 0 I only get the following error message.

InvalidTemplate. Unable to process template language expressions for action 'Condition' at line '0' and column '0': 'The template language function 'length' expects its parameter to be an array or a string. The provided value is of type 'Null'. Please see https://aka.ms/logicexpressions#length for usage details.'.

Null (german) is = Zero (english) Sorry my power automate is in german...

Do you have a tip for me what I could be doing wrong?

Thanks,

Nicolas