GETTING STARTED ATTACHMENT UPLOAD
If you want to track the progress of large file uploads then you need use a slightly different technique than used with standard ATTACH endpoint.
Note: if passing the sid - it must be in the URL querystring and not in the form. eg /ondemand/attach/progress/?sid=
When the user triggers the "Upload" event in the user inferface, you need to call:
This will prepare the attach endpoint to track progress.
Change the endpoint you POST to from /ondemand/attach/ to /ondemand/attach/progress
To get the % complete for the upload then you need to poll:
It will automatically return for the last initialised upload (as done in step 1). If you are doing multiple, then need to pass &progress=