MS Forms - Handling non-required file upload questions -@ChadVKealey

[icovsjl]

 I watched the video (MS Forms - Handling non-required file upload questions) and i am getting the error "ExpressionEvaluationFailed. The execution of template action 'Apply_to_each' failed: the result of the evaluation of 'foreach' expression '@body('Parse_JSON')' is of type 'Null'. The result must be a valid array."

[ScottShearer]

@icovsjl 

The error indicates that the Parse JSON action is receiving a null value.

To begin trouble shooting, take a look at the outputs of previous actions that are used in the Parse JSON action.  Are they what you expected?

[icovsjl]

@ChadVKealey 

[ChadVKealey]

It's hard to diagnose without some additional information. Does your form have more than one "File upload" question? What's being processed in that "Apply to each 2" after the condition?

[icovsjl]

@ChadVKealey  There is only 1 file upload question. "Apply to each 2" is sending an email using the information indicated on the Microsoft form and using those variables to assign a person. the email is indicating who the assigned person is. 

[ChadVKealey]

Can you share a screenshot of what's in that loop? According to the error message, you've got a Parse JSON step in there that's trying to process a null value. So, what information is it supposed to be parsing? 

[icovsjl]

@ChadVKealey 

[ChadVKealey]

If you hover over the "Body" at the top of that apply to each, where is that coming from? Also, the email action you're using doesn't support attaching more than one file. Even if varAttachments has only one file, it's still formatted as an array, which (I suspect) is where the loop is coming from. Also, what's the other thing in the first/top "Attachment" field?

[icovsjl]

Is this the information you needed?

Do you mean this field?

[ChadVKealey]

Well, that confirms my suspicions. The loop is being created because you're calling the "name" value from the output of the parse JSON action which is failing because there's no file attached. That's why the loop itself is failing. If the file upload question must be optional and you must use that action to send the email, you'll need two "versions" or copies of that action: one that's used if there is a file attached and another that's used if there isn't. 

If you use another email action that allows for multiple attachments (like the Outlook "Send email" or "Send email from shared mailbox"), you can just add the variable to the attachments field (after switching to array entry mode) and it won't care if that array is empty. 

[icovsjl]

Thanks! So having the below does not fix this?

I didn't create the original flow but I have been owning it for the last year. I say this because I'm not sure why she chose that email action when she created it. By changing to another email action, will i still have the same result?

[ChadVKealey]

Having that in your flow just tells it what to do if the Parse JSON action fails. As in, if that fails, don't populate the attachment variable. If you try using the output of that action elsewhere downstream in the flow, those actions will fail also.

A lot of people use that email action because it seems easy, but it's limited. For example, it allows a single attachment. If the form will only ever have a single file attached, it's possible to make that action work, but it's a little complicated. You can extract the first (only) attachment name using the expression "first(<variable-name>)?['Name']". The attachment content would use "first(<variable-name>?['ContentBytes']"

Changing to another email action is a bit cleaner. For most of the flows I build like this, I use an existing shared mailbox or have a new one created, then use the "Send email from shared mailbox" action. First, since this is coming from an address within your organization, users are less likely to think it's spam. Second, it allows attachments to be added in the form of an array, so you can just drop that array variable in there. If it's empty, then nothing will be attached, but it won't throw any kind of error.

[icovsjl]

Will changing the file uploaded question to required (currently optional) fix the whole thing?

Would using "send an email (V2)" work? Creating a shared email might be timely.

[ChadVKealey]

No, making the file upload required won't fix it. Well, it would prevent the parse json step from failing, but even if the email sends, the attachment will be broken. 

Shared mailboxes don't consume a license, so they're actually pretty simple and quick to create for someone with access (an Exchange or global M365 admin). However, every org is different, so if that's not a viable option, using the "send an email (v2)" action from the Office 365 Outlook connector will work. Just realize that it will be sending from your Outlook mailbox. Whether that matters or not is something only you can determine. 

If you want to go that route, this video should help you get that set up: https://youtu.be/2mrcTMkwelE?si=NSSPbWMRc1J_gXM1&t=529 

[icovsjl]

Thanks Chad. 

I'm still pretty novice at all this. I rely on amazing YouTube Videos :D! Would it be easy enough to tell me which exact part I need to retool because i'm still not quite understanding?

[ChadVKealey]

Follow the steps in that video to add the "Send an email (v2)" action and attach the "varFiles" variable. Add it below the existing "Send an email notification (v3)" action inside the "Yes" branch of that condition. Then, you can copy the recipient, subject line and body from the old action to the new one. Finally, delete the "Send an email notification (v3)" action. 

Also, I totally understand being new to this. We all were at some point. There are lots of good resources out there (YouTube, Microsoft Learn and more). I also understand that you "inherited" this from someone else. I've found that more of a challenge than building my own flows from the ground up since very few people properly document their flows or add appropriate comments to help you understand what's happening. But the point is, it's your flow now. You should spend some time looking at the completed flow runs (even failed runs) and examining the outputs of each action. That's the best way I've found to really understand what a flow does (when it's not commented/documented).