python web开发框架 - 之 Django Request

使用例子：

>>> from django.http import *
>>> request = HttpRequest()
>>> request.__doc__
>>> help(request)
>>> request.META
29: {}
>>> request.is_ajax()
30: False
>>> request.GET
31: {}
>>> request.FILES
32: {}

以下是request 的源码：

class HttpRequest(object):
    """A basic HTTP request."""

    # The encoding used in GET/POST dicts. None means use default setting.
    _encoding = None
    _upload_handlers = []

    def __init__(self):
        self.GET, self.POST, self.COOKIES, self.META, self.FILES = {}, {}, {}, {}, {}
        self.path = ''
        self.path_info = ''
        self.method = None

    def __repr__(self):
        return '<HttpRequest\nGET:%s,\nPOST:%s,\nCOOKIES:%s,\nMETA:%s>' % \
            (pformat(self.GET), pformat(self.POST), pformat(self.COOKIES),
            pformat(self.META))

    def get_host(self):
        """Returns the HTTP host using the environment or request headers."""
        # We try three options, in order of decreasing preference.
        if 'HTTP_X_FORWARDED_HOST' in self.META:
            host = self.META['HTTP_X_FORWARDED_HOST']
        elif 'HTTP_HOST' in self.META:
            host = self.META['HTTP_HOST']
        else:
            # Reconstruct the host using the algorithm from PEP 333.
            host = self.META['SERVER_NAME']
            server_port = str(self.META['SERVER_PORT'])
            if server_port != (self.is_secure() and '443' or '80'):
                host = '%s:%s' % (host, server_port)
        return host

    def get_full_path(self):
        return ''

    def build_absolute_uri(self, location=None):
        """
        Builds an absolute URI from the location and the variables available in
        this request. If no location is specified, the absolute URI is built on
        ``request.get_full_path()``.
        """
        if not location:
            location = self.get_full_path()
        if not absolute_http_url_re.match(location):
            current_uri = '%s://%s%s' % (self.is_secure() and 'https' or 'http',
                                         self.get_host(), self.path)
            location = urljoin(current_uri, location)
        return iri_to_uri(location)

    def is_secure(self):
        return os.environ.get("HTTPS") == "on"

    def is_ajax(self):
        return self.META.get('HTTP_X_REQUESTED_WITH') == 'XMLHttpRequest'

    def _set_encoding(self, val):
        """
        Sets the encoding used for GET/POST accesses. If the GET or POST
        dictionary has already been created, it is removed and recreated on the
        next access (so that it is decoded correctly).
        """
        self._encoding = val
        if hasattr(self, '_get'):
            del self._get
        if hasattr(self, '_post'):
            del self._post

    def _get_encoding(self):
        return self._encoding

    encoding = property(_get_encoding, _set_encoding)

    def _initialize_handlers(self):
        self._upload_handlers = [uploadhandler.load_handler(handler, self)
                                 for handler in settings.FILE_UPLOAD_HANDLERS]

    def _set_upload_handlers(self, upload_handlers):
        if hasattr(self, '_files'):
            raise AttributeError("You cannot set the upload handlers after the upload has been processed.")
        self._upload_handlers = upload_handlers

    def _get_upload_handlers(self):
        if not self._upload_handlers:
            # If thre are no upload handlers defined, initialize them from settings.
            self._initialize_handlers()
        return self._upload_handlers

    upload_handlers = property(_get_upload_handlers, _set_upload_handlers)

    def parse_file_upload(self, META, post_data):
        """Returns a tuple of (POST QueryDict, FILES MultiValueDict)."""
        self.upload_handlers = ImmutableList(
            self.upload_handlers,
            warning = "You cannot alter upload handlers after the upload has been processed."
        )
        parser = MultiPartParser(META, post_data, self.upload_handlers, self.encoding)
        return parser.parse()