Process response body based on content type

[edgurgel]

Process response body based on content type

[edgurgel]

I understand the issue and I'm looking for a reasonable way of doing this, but there's one small problem with this approach. On async requests you do not receive the body and headers at the same time: https://github.com/edgurgel/httpoison/blob/master/lib/httpoison/base.ex#L38-L49

We gotta find a solution that won't be inconsistent with the way that async requests work. One option is to process the response by yourself without touching headers and body so you can probably do things like:

case HTTPoison.get(....) do
  %HTTPoison.Response{body: body, headers: %{"Content-Type" => "application/json"} -> do_something_json(body)
  %HTTPoison.Response{body: body, headers: %{"Content-Type" => "application/xml"} -> do_something_xml(body)
end

One possible option could be something like this:

defp process_headers(body, state \\ nil) do
  ...
  new_state
end

defp process_response_body(body, state \\ nil) do
  #Do something on the body based on the new_state
  ...
end

process_headers would be called, and the value returned would be passed to the process_response_body as state

I'm afraid this is a complicated solution and I'm not sure how this would behave with previous implementations as it would have a callback with a different arity.

What do you think?

[xtagon]

For asynchronous requests, even though headers and body are not processed at the same time, won't the headers always be processed before the body? They come first in the HTTP protocol.

[edgurgel]

Yeah, I hope hackney always sends the header first :P.

So the idea is to pass the same headers to process_response_body? Or get the processed headers and feed to process_body on the 2nd argument?

processed_headers = process_headers(headers)
processed_body      = process_response_body(body, processed_headers)

# => %HTTPoison.Response{body: processed_body, headers: processed_headers, ...}

This seems to be the easier way to do this.

[xtagon]

Well, personally I don't care whether the headers passed are processed or not, because I'm not processing them. But your last example probably makes the most sense.