Sending a JSON file within a Multipart-form data HTTP POST

[zealandva]

I am trying to upload a JSON file along with a PDF file to a REST API using Flow's HTTP POST command using a multipart-form JSON command.  I can upload the file successfully when using POSTMAN and below is the successful code used by POSTMAN.

Below is the Multipart JSON I am using within the HTTP POST body

{
	"$content-type": "multipart/form-data",
	"$multipart": [{
			"headers": {
				"Content-Disposition": "form-data; name=\"profile\"; filename=\"base7.json\""
			},
			"body": "@{body('Get_file_content_JSON')}"
		},
		{
			"headers": {
				"Content-Disposition": "form-data; name=\"file\"; filename=\"Adobe Sign Form Field.pdf\""
			},
			"body": {
				"$content-type": "application/pdf",
				"$content": "@{base64(body('Get_file_content_Signed_PDF'))}"
			}
		}
	]
}

Howeven when I run the Flow the REST API sends back an upload failure.  When I send the HTTP POST to a debugging FLOW that contains "When an HTTP request is received" to capture the output, the JSON file is reconized as "Content-Type: text/plan".

When I point POSTMAN to the same debugging FLOW that contains "When an HTTP request is received" to capture the output, the JSON file is reconized as "Content-Type: application/json".

I have tried to define the "Content-Type application/json in both the header and the body but I must not be formatting it correctly.  I suspect the REST API is not accepting the txt file because it is expecting a JSON file which is causing the upload to fail.  Any guidance would be greatly appreciated.

[v-litu-msft]

Hi @zealandva,

Could you please share the screenshot of Flow configuration?

I can see the output both the json and text are the same, you can initialize a variable as an object, then store content into it.

Best Regards,
Community Support Team _ Lin Tu
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[zealandva]

I have been trying to get this to work two ways.  The First was was to upload the Base7.json file to SharePoint and then pull the file into Flow.  As requested, I initalized a variable (Object) and then set the value to the SharePoint file.

The following is the output when I run the Flow.

The second way I have been trying to get this to work is just using Compose and pasting the JSON text (see below).

Below is the output from the above step when I enter the Compose Profile as a String.

I also changed the ProfileJSON variable from String to Object and below is the output

[zealandva]

If there is some sort of problem with the Base7.json file that I saved to SharePoint, creating a new ProfileJSON object by pasting in the text should eliminate that as a potential problem.  I have not added the content-type "application/json" from the header and as follows:

{
	"$content-type": "multipart/form-data",
	"$multipart": [{
			"headers": {
				"Content-Disposition": "form-data; name=\"profile\"; filename=\"base7.json\""
			},
			"body": "@{variables('ProfileJSON')}"
		},
		{
			"headers": {
				"Content-Disposition": "form-data; name=\"file\"; filename=\"Adobe Sign Form Field.pdf\""
			},
			"body": {
				"$content-type": "application/pdf",
				"$content": "@{base64(body('Get_file_content_Signed_PDF'))}"
			}
		}
	]
}

I am able to get the Output to reconize the variable object ProfileJSON as "Content-Type: application/json; charset=utf-8"

However, when I run this against the iManage REST API I get the following error.

That being said, for some reason I can get POSTMAN to work but it will not work in Flow.  The only difference in the Output between Postman and Flow is the "Content-Type: application/json; charset=utf-8" is above the line "Content-Disposition:..." and the "; charset=utf-8" at the end.  Likly the most important difference is the output starts with including "{"$content":" at the beginning of the json object which is likly why the iManage REST API is throwing the error.

If I modify the body as follows

{
	"$content-type": "multipart/form-data",
	"$multipart": [{
			"headers": {
				"Content-Disposition": "form-data; name=\"profile\"; filename=\"base7.json\""
			},
			"body": "@{variables('ProfileJSON')}"
		},
		{
			"headers": {
				"Content-Disposition": "form-data; name=\"file\"; filename=\"Adobe Sign Form Field.pdf\""
			},
			"body": {
				"$content-type": "application/pdf",
				"$content": "@{base64(body('Get_file_content_Signed_PDF'))}"
			}
		}
	]
}

The output does not see the file as JSON, rather it indicates Content=Type: text/plain; charset=utf-8

[zealandva]

Here is the Flow after authentication.  I have two HTTP Posts running tandem so that I can capture the output of one and the other pokes the iManage REST API

Here is the result after I run the Flow

And here is the full body result

[SvenG]

Did you ever resolve this? 

I'm also having trouble with uploading Files through HTTP action. I even didn't know that you can use a json syntax for the HTTP body. Where did you get this?

Regards

Sven