It is great progress that we now have the ability to webRequest.filterResponseData() to read and possibly modify the response body. However, while porting my chrome extension into FF WebExtension, I came across this problem in trying to compile all the request data, I am missing the request body now.
I am using webRequest.onBeforeRequest with extraInfoSpec ['requestBody'], however, it returns “Upload streams with headers are unsupported”. While it actually works in normal form posts, I cannot complete my WebExtension without getting the request body, which unfortunately is a stream as well. I am not sure why but it is just an API call from a flash game, not a file upload or anything like that. I was almost sure it would behave as a regular form POST.
Is it possible for us to also have a webRequest.filterRequestData() method? It would probably behave the same as the response counterpart, but reverse direction. This would also mean ability to modify request bodies.
Can’t stress how important this is for my WebExtension. Thank you!