scrapy/scrapy/http/response/text.py

107 lines
3.6 KiB
Python

"""
This module implements the TextResponse class which adds encoding handling and
discovering (through HTTP headers) to base Response class.
See documentation in docs/topics/request-response.rst
"""
import re
from scrapy.xlib.BeautifulSoup import UnicodeDammit
from scrapy.http.response import Response
from scrapy.utils.python import memoizemethod_noargs
from scrapy.utils.encoding import encoding_exists, resolve_encoding
from scrapy.conf import settings
class TextResponse(Response):
_DEFAULT_ENCODING = settings['DEFAULT_RESPONSE_ENCODING']
_ENCODING_RE = re.compile(r'charset=([\w-]+)', re.I)
__slots__ = ['_encoding', '_cached_benc', '_cached_ubody']
def __init__(self, url, status=200, headers=None, body=None, meta=None, \
flags=None, encoding=None):
self._encoding = encoding
self._cached_benc = None
self._cached_ubody = None
super(TextResponse, self).__init__(url, status, headers, body, meta, flags)
def _get_url(self):
return self._url
def _set_url(self, url):
if isinstance(url, unicode):
if self.encoding is None:
raise TypeError('Cannot convert unicode url - %s has no encoding' %
type(self).__name__)
self._url = url.encode(self.encoding)
else:
super(TextResponse, self)._set_url(url)
url = property(_get_url, _set_url)
def _set_body(self, body):
self._body = ''
if isinstance(body, unicode):
if self.encoding is None:
raise TypeError('Cannot convert unicode body - %s has no encoding' %
type(self).__name__)
self._body = body.encode(self._encoding)
else:
super(TextResponse, self)._set_body(body)
def replace(self, *args, **kwargs):
kwargs.setdefault('encoding', getattr(self, '_encoding', None))
return Response.replace(self, *args, **kwargs)
@property
def encoding(self):
return self._get_encoding(infer=True)
def _get_encoding(self, infer=False):
enc = self._declared_encoding()
if enc and not encoding_exists(enc):
enc = None
if not enc and infer:
enc = self._body_inferred_encoding()
if not enc:
enc = self._DEFAULT_ENCODING
return resolve_encoding(enc)
def _declared_encoding(self):
return self._encoding or self._headers_encoding() \
or self._body_declared_encoding()
def body_as_unicode(self):
"""Return body as unicode"""
if self._cached_ubody is None:
self._cached_ubody = self.body.decode(self.encoding, 'replace')
return self._cached_ubody
@memoizemethod_noargs
def _headers_encoding(self):
content_type = self.headers.get('Content-Type')
if content_type:
m = self._ENCODING_RE.search(content_type)
if m:
encoding = m.group(1)
if encoding_exists(encoding):
return encoding
def _body_inferred_encoding(self):
if self._cached_benc is None:
enc = self._get_encoding()
dammit = UnicodeDammit(self.body, [enc])
benc = dammit.originalEncoding
self._cached_benc = benc
# UnicodeDammit is buggy decoding utf-16
if self._cached_ubody is None and benc != 'utf-16':
self._cached_ubody = dammit.unicode
return self._cached_benc
def _body_declared_encoding(self):
# implemented in subclasses (XmlResponse, HtmlResponse)
return None