Content-Type: application/json shouldn't have a charset parameter.

[gabisurita]

Pyramid JSON renderer returns Content-Type: application/json; charset=utf-8, but according to RFC 4627, the application/json type doesn't have a charset parameter. It also describes why it's not needed.

See http://stackoverflow.com/questions/13096259/can-charset-parameter-be-used-with-application-json-content-type-in-http-1-1

[mmerickel]

What version of pyramid and webob are you using? This has been fixed but I can't remember if it's released yet (but I think it is).

[gabisurita]

I'm using pyramid-1.7.3 with WebOb-1.6.3. I think it's still unreleased. This was solved on #2706, right?

Thank you and sorry for the repost.

[mmerickel]

That PR you linked was reverted in favor of another solution as it was backward incompatible. I'm thinking of Pylons/webob#197 which was released in webob 1.6.0.

Here is a test case that passes. Can you update it to reproduce your issue?

from pyramid.config import Configurator
from webtest import TestApp

def json_view(request):
    return {}

config = Configurator()
config.add_view(json_view, renderer='json')
app = config.make_wsgi_app()

testapp = TestApp(app)
r = testapp.get('/')
assert r.content_type == 'application/json'

[gabisurita]

If we assert response.headers['Content-Type'] instead of response.content_type, the following test doesn't pass:

from pyramid.config import Configurator
from webtest import TestApp

def json_view(request):
    return {}

config = Configurator()
config.add_view(json_view, renderer='json')
app = config.make_wsgi_app()

testapp = TestApp(app)
r = testapp.get('/')
assert r.headers['Content-Type'] == 'application/json'

[mmerickel]

Upgrading to webob 1.7.0rc1 fixes this, however it also emits a RuntimeWarning so pyramid is probably doing something a little bit wrong here.

[digitalresistor]

Pyramid changes from text/html; charset=utf-8 to setting content_type to application/json the warning you will be getting here is that WebOb has explicitly removed the charset.

In the future WebOb will remove all content_type_parameters when setting the content_type.

Pyramid isn't doing anything wrong, WebOb is warning about changed behaviour that a user may not be expecting.

[mmerickel]

Is there a way for pyramid to avoid this warning in the update? Obviously people are going to open more bugs in our tracker if every renderer='json' view they have starts emitting a RuntimeWarning. Could we delete the charset if it's utf8 or something?

[digitalresistor]

res.charset = None
res.content_type = 'application/json'

Although it sounds like I should modify it instead to be a DeprecationWarning and that won't be shown by default...

[digitalresistor]

res.headers['Content-Type'] = 'application/json'

Bypasses all of it, and does the right thing, and no warning will be emitted. It's because of the "magic" that res.content_type does (to keep the content-type parameters which is going away) that I wanted to warn users.

[digitalresistor]

This is now fixed in WebOb 1.7.0rc2

[mmerickel]

I'm trying to decide if it's worth just setting the header directly. Thoughts?

[digitalresistor]

With the pinning of 1.7.0 in the has_body ticket there is no need for it.