Attachment Array to String and back to Array - Files are corrupted

[aallen5658]

Hi All! I am getting the attachments from a Teams post (groups mail), appending selected types to an array variable, converting that array to a string, passing it to a Child Flow and then using Parse JSON to convert it back to an array so I can add the attachments to a SharePoint Folder. Everything runs and looks like it works but the files are corrupted - this is true for pdf, jpeg, and docx.  

Using compose actions, all my attachment outputs (original, filter, variable) look the same, but I don't have dynamic options to use the file name and content bytes for my array variable. I'm not sure if the issue is with the Parse JSON or with my array variable.   Any help would be much appreciated as I'm not a programmer and was ecstatic when I finally got a schema that let me pass Parse JSON. **note** I call the text input the Array but it's a string**

____________JSON____________

{

    "type": "array",

    "items": {

        "type": "object",

        "properties": {

            "@@odata.type": {

                "type": "string"

            },

            "id": {

                "type": "string"

            },

            "lastModifiedDateTime": {

                "type": "string"

            },

            "name": {

                "type": "string"

            },

            "contentType": {

                "type": "string"

            },

            "size": {

                "type": "integer"

            },

            "isInline": {

                "type": "boolean"

            },

            "contentBytes": {

                "type": "string"

            }

        },

        "required": [

            "@@odata.type",

            "id",

            "lastModifiedDateTime",

            "name",

            "contentType",

            "size",

            "isInline",

            "contentBytes"

        ]

    }

}

_______________Array Variable_________________

[Nived_Nambiar]

Hi @aallen5658 

One thing could you show me how you have designed the create file action ?

May be there is a possibility is it is not correct from parameter passing point  in create file action?

[Matthy79]

Hello @aallen5658,

I agree with @Nived_Nambiar that it might be a problem with the create action, api call or whatever you are using this passed files.

But here are some thoughts about this flow in general.

- You should rename your actions. It makes the flow more readable and doing it afterwards is hard because there are a lot of bugs when renaming actions if you already use them in later steps.

- You shouldn't use "Manually trigger a flow" for child flows. Use "PowerApps (v2)" instead. Microsoft release a bug once or twice a year, where all flows will fail using "Manually trigger" when called as a child flow. It's because they add some new functionality (zip code or whatever) and these fields are missing when you call it as a child flow. They usually fix the bug during the first 24 hours, but you will have the problem finding and fixing all failed runs.

- You can use "union" (and set variable) to append to your existing array. That way you won't need "Apply to each 6".

- You should check for "endswith" and not "contains" for the file extension. Another way to check it. Create an array with all allowed extensions and check if "toLower(last(split(item()?['name'],'.')))" is a part of this array (contains).

[aallen5658]

@Nived_Nambiar 

Thanks for the reply. Here is my create file action

[aallen5658]

@Matthy79 

Thanks for the reply.  I added my create file above.  

I don't see a PowerApps v2 trigger, so I might not be able to do that.

How do you use union and set variable to add everything to the array? 

[Matthy79 · Accepted solution]

I can't believe that you don't have PowerApps v2 trigger. This is a basic functionality.

For union. Just add a compose action where you use "union(YOURARRAY, NEWARRAY)". After that you can set the variable to the output of this compose action.

For your content problem. Try using base64ToBinary(YOURBASE64STRING)

[aallen5658]

Thanks @Matthy79 .  I'm getting an Invalid Template error on the base64toBinary.  Does this mean, the string coding isn't the issue? Also if the 64 to Binary work, do I have my Parse JSON input correct? 

[Matthy79]

I thought Attachments is an array.

What is your expression in “Binary String”?

You should use this expression during “Save Files To Folder” for File Content.

[aallen5658]

Yes, It is so it was base64tibinary(triggerBody()['text']) where triggerBody()['text'] was the string of the array sent over from the parent flow. 

I tried it a second time, sent my string though Parse JSON to get the array back. And then put the Body of Parse JSON in the expression for the file content.  I got the same error. 

Here's an overview

[Matthy79]

You can’t store an array. You have to apply to each attachment and store each one inside the loop.

What I don’t understand. You already have your “parse json” and used “contentBytes”. Didn’t that create an apply to each? Just use the same Dynamic Content but with base64ToBinary around it.

[aallen5658]

Yes, It's in a loop.  I tried looking for contentbytes in dynamic content but if I'm in an expression it's not an option, so I thought I was supposed to use Body? 

[Matthy79]

Did it work now? If not just use contentBytes from the dynamic content, go right to that just inserted expression, hit “ctrl+a” and “ctrl+c” and post what is in the clipboard here. It has to be something like “@{item(‘Apply_to_each’)[‘contentBytes’]}”

[aallen5658]

YES!!! Thank you @Matthy79  The original is @{items('Apply_to_each_2')['contentBytes']}

So I tried: base64tobinary(items('Apply_to_each_2')['contentBytes']) 

Thank you!!! I had tried it a few messages ago but also took out the apply to each. I think I need to work on my understanding of Apply to Each. It's tripped me up a few times now.