Azure Logic Apps - Get Blob Content - Setting Content type

Question

The Azure Logic Apps action \"Get Blob Content\" doesn\'t allow us to set the return content-type.

By default, it returns the blob as binary (octet-stream), which is

Answer 1

Workaround I found is to use the Logic App expression base64ToString.

For instance, create an action of type "Compose" (Data Operations group) with the following code:

        "ComposeToString": {
            "inputs": "@base64ToString(body('Get_blob_content').$content)",
            "runAfter": {
                "Get_blob_content": [
                    "Succeeded"
                ]
            },
            "type": "Compose"
        }

The output will be the text representation of the blob.

Answer 2

After fiddling much with Logic Apps, I finally understood what was going on.

The JSON output from the HTTP request is the JSON representation of an XML payload:

{
  "$content-type": "application/xml",
  "$content": "77u/PD94bWwgdm..."
}

So we can decode it, but it is useless really. That is an XML object for Logic App. We can apply xml functions to it, such as xpath.

Answer 3

1. You would need to know the content-type.
2. Use @{body('Get_blob_content')['$content']} to get the content part alone.

Answer 4

So I had a blob sitting in az storage with json in it. Fetching blob got me a octet back that was pretty useless, as I was unable to parse it.

BadRequest. The property 'content' must be of type JSON in the 'ParseJson' action inputs, but was of type 'application/octet-stream'.

So I setup an "Initialize variable", content type of string, pointing to GetBlobContent->File Content. The base64 conversion occurs under the hood and I am now able to access my json via the variable.

No code required.

JSON OUTPUT...

FLOW, NO CODE...

Enjoy! Healy in Tampa...