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 useless in most cases. In general it would be useful to have text (e.g. json, xml, csv, etc.).

I know the action is in beta. Is that on the short term roadmap?

Denominational

Have you tried setting the blob to the correct content-type? #10040903 – Fiberglass

Yes. The blob was /json. – Denominational

Answer 1

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.

Denominational

Answer 2

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...

Olecranon

Answer 3

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.

Denominational

thanks that was progressing. i was able to parse it but not able to put that parsed in to a slack message. – Memory

I am getting the results as 'click to download' link as it is reading the ftp into a binary. Could not find a way to resolve it – Memory

Answer 4

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

Larva

Answer 5

Is enough to "Initialize Variable" and take the output of the Get Blob Content as type "String". This will automatically parse the content:

Ira