HTTP request return base64 encoded content, create file in OneDrive

[arodriguez107]

I'm making an HTTP GET request that returns file attachment content encoded in base64 format.  You'll see the request was made with a "Content-Type" of "application/json", but the output is returned as "application/pdf" because the downloaded document is a PDF.  I've seen several posts similar to this where a ParseJSON step with a base64ToBinary or base64ToString would be appropriate, but since the output is "application/pdf", this doesn't seem to work.  When I take the direct output from the HTTP request and run a create file in OneDrive, the file is created, but when I try to open the file, I get an error message "Failed to load PDF document." The file appears like it's encoded in base64 format.

Is there some way to take this output and convert it back to a PDF document successfully?

   

[v-xiaochen-msft]

Hi @arodriguez107 ,

Please try to save the output of http directly into onedrive.

If the pdf still won't open, it means the file itself stored on the api server is corrupted.

Best Regards,

Wearsky

[arodriguez107]

Hi @v-xiaochen-msft.. I did try that as well and I'm getting the same error so it looks like the file is corrupted at storage.  Is there an alternate way to store this so that it isn't corrupted?  Thanks!

[v-xiaochen-msft]

Hi @arodriguez107 ,

I don't know how you store the file. This appears to be a 3 party API, and the issue doesn't seem to be related to the flow.

Best Regards,

Wearsky

[arodriguez107 · Accepted solution]

I was able to figure out how to convert the file from Base64 to a PDF after making an HTTP request. 

1. First, I made the HTTP GET request and returned an object with the content being returned as content encoded in base64 format. 

The output looks like this:

{
  "$content-type": "application/pdf",
  "$content": "<returned base64 output>"
}

2. I then added a Compose step named "Base64ToString" taking the output from the previous HTTP request and wrapping it in a string function.

3. After converting the output to a string, I created another Compose step named "Base64ToBinary" and wrapped that around the output of the previous Base64ToString step, converting the Base64 string to binary.

4. The last step, Create file, took the output from the previous Base64ToBinary as its "File Content" parameter, I just added a default folder path and generic file name, making sure to suffix it with the ".pdf" extension.  The name can be also added dynamically if, at some point in this process, you create a variable or pull the name from the request body.

I can confirm that this process works for me each time it's used, taking Base64 formatted content and converting it back to a pdf.  I hope this helps others looking to run this same or at least similar process.

[televisi]

Hello @arodriguez107 

How did you able to receive HTTP GET with Accept: application/json for the file?

As when I tried to do something similar (I'm trying to download .msi file); it returned an error:

406 - Client browser does not accept the MIME type of the requested page

The page you are looking for cannot be opened by your browser because it has a file name extension that your browser does not accept

I tried with postman and received the similar error:

Thanks

[arodriguez107]

Check the Accept header in your GET request. It should match the content type that the server is capable of providing. If you're not sure what content type the server will respond with, you can try setting the Accept header to */*, which indicates that the client can handle any media type.  In my case, the server returned json formatted data, so that worked for me by defining that in my headers.  Perhaps the server you're making the call to only returns "text/html".  

[televisi]

Ah, thanks for the tips.

I added "accept: */*" header and the server returned with "content-type: application/octet-stream"

I guess back to the drawing board for me then...

[arodriguez107]

Instead of 'Accept', did you try defining the header's key to 'Content-Type' and it's value to 'application/json'?

[televisi]

Yea, the same, unfortunately:

[aldenniklas]

THANK YOU! This was driving me nuts!