cowboy 2.9 - read_urlencoded_body/1 vs read_body/1

[ferencboi]

Hey there,
I have noticed when I am sending a POST request with payload (JSON), read_body/1 does not return the JSON string the client has sent via a jQuery ajax POST request.
However read_urlencoded_body/1 is able to read the payload and returns a single tuple list containing the escaped JSON string and the boolean 'true'.
Is this the expected behavior? Shouldn't read_body return the JSON string instead? Maybe I am missing a client side request parameter?

[essen]

Please show the code.

[ferencboi]

Ok, found the issue.
In the single router I currently have I start with {ok, PostVals, Req} = cowboy_req:read_urlencoded_body(Req0), which will change the state of Req0, so when in the next line I want to get the payload with read_body/1, read_body/1 yields <<>> even if I use Req0 or Req as argument.
The problem is with my implementation. I have to pre-check the Content-Type header and process the POST data accordingly.