[Solved]-I get a 400 Bad Request error while using django-piston

This is happening because Piston doesn’t like the fact that ExtJS is putting “charset=UTF-8” in the content-type of the header.

Easily fixed by adding some middleware to make the content-type a bit more Piston friendly, create a file called middleware.py in your application base directory:

class ContentTypeMiddleware(object):

    def process_request(self, request):
        if request.META['CONTENT_TYPE'] == 'application/x-www-form-urlencoded; charset=UTF-8':
            request.META['CONTENT_TYPE'] = 'application/x-www-form-urlencoded'
        return None

Then simply include this middleware in your settings.py:

MIDDLEWARE_CLASSES = (
    'appname.middleware.ContentTypeMiddleware',
)

Proposed solutions still did not work for me (django 1.2.3/piston 0.2.2) so I’ve tweaked joekrell solution and this finally works (I’m only using POST and PUT, but presumably you can add other verbs to the list):

class ContentTypeMiddleware(object):

def process_request(self, request):

    if request.method in ('POST', 'PUT'):
        # dont break the multi-part headers !
        if not 'boundary=' in request.META['CONTENT_TYPE']:
            del request.META['CONTENT_TYPE']

with:

MIDDLEWARE_CLASSES = (
'appname.middleware.ContentTypeMiddleware',
)

I haven’t noticed any side-effect, but I can’t promise it’s bullet-proof.

I have combined some of what other people have said, and added support for any content type, json for instance…

class ContentTypeMiddleware(object):
    def process_request(self, request):
        if request.method in ('POST', 'PUT') and request.META['CONTENT_TYPE'].count(";") > 0:
            request.META['CONTENT_TYPE'] = [c.strip() for c in request.META['CONTENT_TYPE'].split(";") ][0]
        return None

I thought Eric’s solution worked the best but then ran into problems when saving things in admin. This tweak seems to fix it if anyone else comes across it:

class ContentTypeMiddleware(object):

    def process_request(self, request):
        if request.method in ('POST') and not 'boundary=' in request.META['CONTENT_TYPE']:
            request.META['CONTENT_TYPE'] = [c.strip() for c in request.META['CONTENT_TYPE'].split(";") ][0]
        return None

In utils.py, change this.

def content_type(self):
    """
    Returns the content type of the request in all cases where it is
    different than a submitted form - application/x-www-form-urlencoded
    """
    type_formencoded = "application/x-www-form-urlencoded"

    ctype = self.request.META.get('CONTENT_TYPE', type_formencoded)

    if ctype.strip().lower().find(type_formencoded) >= 0:
        return None

    return ctype

https://bitbucket.org/jespern/django-piston/issue/87/split-charset-encoding-form-content-type

This is solution which worked for me, after a tweak:

class ContentTypeMiddleware(object):

    def process_request(self, request):
        if 'charset=UTF-8' in request.META['CONTENT_TYPE']:
            request.META['CONTENT_TYPE'] = request.META['CONTENT_TYPE'].replace('; charset=UTF-8','')
        return None

We had a resource that was simply updating a timestamp based on the request credentials and PUT. It turns out that Piston does not like PUT without a payload. Adding an empty string payload ” fixed it.

A quick Google search indicates that other systems like Apache may not like PUT without a payload, as well.