Issue with file attachment using Approval Mail

[FedericoCoppola]

Hi all,
I have some issue using file attachment with Approval Mail.

After many test I have followed this article:

https://powerusers.microsoft.com/t5/Power-Automate-Community-Blog/Adding-multiple-attachments-to-the...

but I had some issue

For example with TXT file I got this error:

Unable to process template language expressions in action 'Append_to_array_variable' inputs at line '1' and column '41266':
'The template language expression 'body('Get_attachment_content_2')?['body']' cannot be evaluated because property 'body'
cannot be selected. Property selection is not supported on values of type 'String'.
Please see https://aka.ms/logicexpressions for usage details.'.

After that I have tried to use base64() function too and I got a very strange behaviour from my flow:

I saw base64() function when I set it as argument of "Content" inside Array Input Box.
Later after that I saved and come back inside list I did not see base64() again!

Than when I see files atached to email they are corrupted if I tried to open them (in this picture for example is about an Excel file).

I have tried to delete and create many times boxes about Attachments inside Power Automate flow without success.

After many attempts I wrote input value of my array as:

{

"Name": Display name for the new file being created,

"Content":Content of the file --> without quotes

}

Now it seems to work fine but it is very strange.

I have checked and there are not empty space (some times generate issue)

Can someone suggest me something?

Thanks

[v-bacao-msft]

Hi @FedericoCoppola ,

Please refer to the following screenshot to update the flow configuration:

outputs('Get_attachment_content')?['body'].$content

Best Regards,

[Paulie78]

Most of the instructions that are out there lead to corrupt attachments from approvals, check out this blog post I wrote which has the correct method detailed:

Add multiple attachments to an approval email with Power Automate 

Please...

If I answered your question Accept it as a solution ✔️ 

If I helped you out, please give me some Kudos 👍

Thanks 😙

[FedericoCoppola]

Hi all,

Thanks for your reply.

@v-bacao-msft thanks for your suggestion.

I have seen that you don't use doubles quote with "contents" variable too.

@Paulie78 thanks so much for that article I did not find it. In you suggested article there are more parameters about attached files that can help flow to manage them.

I will try them and I will keep you update

Thanks

[Paulie78]

No problem - try it and report back if you get a problem. That blog post has solved the problem for many people.

[FedericoCoppola]

Hi @Paulie78 ,

I am trying to use your solution, but I dont understand how can I use it.

{
  "content": {
    "$content-type": "@{body('Get_attachment_content')['$content-type']}",
    "$content": "@{body('Get_attachment_content')['$content']}"
  },
  "Name": "@{items('Build_Attachment_array')?['DisplayName']}"
}

If I insert this instruction inside my Array I get the following error from Microsoft Power Automate:

Flow save failed with code 'InvalidTemplate' and message 'The template validation failed: 'The repetition action(s) 'Build_Attachment_array' referenced by 'inputs' in action 'Append_to_array_variable' are not defined in the template.'.'.

How can I solve this issue?
Thanks so much
Federico

[Paulie78]

It is a shame your screenshot does not go slightly higher! In the example from my blog post Build_Attachment_Array is the name of the loop which collects the attachment data, yours might be called Apply_to_each for example. 

If you do a slightly bigger screenshot I can tell you how to change the expression, or maybe I have told you enough to figure it out now.

[Jay-Encodian]

@FedericoCoppola @Paulie78 

You should not need to do this... as passing the file content should suffice. Please see below:

I have just tested this and its fine, note the run history which is correctly populating the full file content value:

This also works for simple file types (like TXT files):

There are loads onward issues which can occur when you work with Base64 directly... the PA team have been upgrading to OpenApi which in some circumstances re-encode base64 strings (because it doesn't know a string already is encoded)... you can;t see this in your Input/Output you'll just get a corrupt file. It is possible work directly with the base64 element of a file content but with caution... not all regions / actions have been upgraded and you may have differing results across different flows and other users.

HTH

Jay

[Paulie78]

@Jay-Encodian you are right, you should not have to do it, and for certain types of files you don't need to. But you might find the behaviour that you demonstrated above is inconsistent between tenants, which is why there are messages from people with no need to do this, and others where it simply does not work without explicitly setting the content type disposition.

I only discovered this because I built the same flow on my tenant and exactly the same flow for a customer. Mine worked, theirs didn't. When I examined the outputs, I could see theirs did not include a content type. Their attachments were corrupt, mine were fine.

I had imagined before this happened that all would be the same, but I was wrong.

So, I don't know what the conclusion is based on what I just said, but something to be aware of. However I never understand why the need to convert to base64 as you can see in the JSON the file is already Base64 when it comes in to Power Automate.

[Jay-Encodian]

@Paulie78 this is to do with the OpenApi roll out... we're seeing loads of issues as we do lots with file merging etc and fully aware different tenants and even different triggers / actions cause flows to behave in certain ways.

This is typically sorted by not accessing the data directly and letting the actions write in the data... I know MS have added some extra handling to sort out the discrepancies (though there may well be some). Your post should cover all the scenarios but the linked article just writing in a base64 string is wrong... it will cause loads of issues (as per the comments on the post).

Anyhow 🙂 - @FedericoCoppola worth trying as per the post I replied, then if this still doesn;t work please share a screen of each file from the output (append to array variable) as that will tell us where is is going wrong... it will then be over to @Paulie78 approach.

[FedericoCoppola]

Hi @Paulie78 ,

thanks so much!
I have change name of Apply to each loop with mine and I did not get any error!

I have another issue:

I have applied your suggestion and it works for the first array that I attached to approval mail.

After that, I have a second array for a second approval mail.
I have created this second array due to I get updated files from sharepoint.

I do not see any attachment with second array.. is it very strange and I do not understand why it happen.
Any error appear about it when I save or when I executed flow.

Here, you can see that I get attachments for a second time inside the flow from SP List and than
I insert them inside a second array.

How can I solve it?

[Paulie78]

First, check the run history - see what the contents of your second array is?

[FedericoCoppola]

Hi @Paulie78,

I have checked the run history. In run history there is not any error about flow.

Get attachments has got all SP List attachments inside body.

After that there is "Apply to Each loop", inside this loop there are

"Get attachment content" and "Append to array" boxes.
Body of Append to array show details about the first file.

About second and third file, "Apply to each" show just option to download details.

Is it possible have multiple array inside a flow?

Thanks so much for your help!

[FedericoCoppola]

Dear @Jay-Encodian 
Thanks for your suggestions!

[Jay-Encodian]

@FedericoCoppola - the 'Click to download' appears when the data is to large to render in the results... you need to click and download, you can then check the JSON...

But the easier way to the check the value of the array is to look in the 'Input' for the approval action... that will show you the data sent to the action.

[Paulie78]

It's possible to have multiple arrays. Just add a compose with the array that you are having problems with. Then you can easily view it in the run history and see if it is empty

[FedericoCoppola]

Yes, I can see JSON details about file.

It seems to be ok...

[FedericoCoppola]

Hi @Paulie78 ,

How can I do it? I am not expert about Power Automate.

[FedericoCoppola]

I can't think that I can use this solution
I do not have Library Files, I use SP list.

Thanks!
Federico

[FedericoCoppola]

I prefer close this discussion.
Thanks so much @Paulie78, I have solved issue about this error:

Unable to process template language expressions in action 'Append_to_array_variable' inputs at line '1' and column '41266':
'The template language expression 'body('Get_attachment_content_2')?['body']' cannot be evaluated because property 'body'
cannot be selected. Property selection is not supported on values of type 'String'.
Please see https://aka.ms/logicexpressions for usage details.'.

Best regards
Federico