1 from django.utils import simplejson

     2 import cgi

     3 

     4 class JSONFilter(object):

     5     def __init__(self, app, mime_type='text/x-json'):

     6         self.app = app

     7         self.mime_type = mime_type

     8 

     9     def __call__(self, environ, start_response):

    10         # Read JSON POST input to jsonfilter.json if matching mime type

    11         response = {'status': '200 OK', 'headers': []}

    12         def json_start_response(status, headers):

    13             response['status'] = status

    14             response['headers'].extend(headers)

    15         environ['jsonfilter.mime_type'] = self.mime_type

    16         if environ.get('REQUEST_METHOD', '') == 'POST':

    17             if environ.get('CONTENT_TYPE', '') == self.mime_type:

    18                 args = [_ for _ in [environ.get('CONTENT_LENGTH')] if _]

    19                 data = environ['wsgi.input'].read(*map(int, args))

    20                 environ['jsonfilter.json'] = simplejson.loads(data)

    21         res = simplejson.dumps(self.app(environ, json_start_response))

    22         jsonp = cgi.parse_qs(environ.get('QUERY_STRING', '')).get('jsonp')

    23         if jsonp:

    24             content_type = 'text/javascript'

    25             res = ''.join(jsonp + ['(', res, ')'])

    26         elif 'Opera' in environ.get('HTTP_USER_AGENT', ''):

    27             # Opera has bunk XMLHttpRequest support for most mime types

    28             content_type = 'text/plain'

    29         else:

    30             content_type = self.mime_type

    31         headers = [

    32             ('Content-type', content_type),

    33             ('Content-length', len(res)),

    34         ]

    35         headers.extend(response['headers'])

    36         start_response(response['status'], headers)

    37         return [res]

    38 

    39 def factory(app, global_conf, **kw):

    40     return JSONFilter(app, **kw)