""" This module implements a class which returns the appropriate Response class based on different criteria. """ from mimetypes import MimeTypes from pkgutil import get_data from io import StringIO from scrapy.http import Response from scrapy.utils.misc import load_object from scrapy.utils.python import binary_is_text, to_bytes, to_unicode class ResponseTypes: CLASSES = { 'text/html': 'scrapy.http.HtmlResponse', 'application/atom+xml': 'scrapy.http.XmlResponse', 'application/rdf+xml': 'scrapy.http.XmlResponse', 'application/rss+xml': 'scrapy.http.XmlResponse', 'application/xhtml+xml': 'scrapy.http.HtmlResponse', 'application/vnd.wap.xhtml+xml': 'scrapy.http.HtmlResponse', 'application/xml': 'scrapy.http.XmlResponse', 'application/json': 'scrapy.http.TextResponse', 'application/x-json': 'scrapy.http.TextResponse', 'application/json-amazonui-streaming': 'scrapy.http.TextResponse', 'application/javascript': 'scrapy.http.TextResponse', 'application/x-javascript': 'scrapy.http.TextResponse', 'text/xml': 'scrapy.http.XmlResponse', 'text/*': 'scrapy.http.TextResponse', } def __init__(self): self.classes = {} self.mimetypes = MimeTypes() mimedata = get_data('scrapy', 'mime.types').decode('utf8') self.mimetypes.readfp(StringIO(mimedata)) for mimetype, cls in self.CLASSES.items(): self.classes[mimetype] = load_object(cls) def from_mimetype(self, mimetype): """Return the most appropriate Response class for the given mimetype""" if mimetype is None: return Response elif mimetype in self.classes: return self.classes[mimetype] else: basetype = f"{mimetype.split('/')[0]}/*" return self.classes.get(basetype, Response) def from_content_type(self, content_type, content_encoding=None): """Return the most appropriate Response class from an HTTP Content-Type header """ if content_encoding: return Response mimetype = to_unicode(content_type).split(';')[0].strip().lower() return self.from_mimetype(mimetype) def from_content_disposition(self, content_disposition): try: filename = to_unicode( content_disposition, encoding='latin-1', errors='replace' ).split(';')[1].split('=')[1].strip('"\'') return self.from_filename(filename) except IndexError: return Response def from_headers(self, headers): """Return the most appropriate Response class by looking at the HTTP headers""" cls = Response if b'Content-Type' in headers: cls = self.from_content_type( content_type=headers[b'Content-Type'], content_encoding=headers.get(b'Content-Encoding') ) if cls is Response and b'Content-Disposition' in headers: cls = self.from_content_disposition(headers[b'Content-Disposition']) return cls def from_filename(self, filename): """Return the most appropriate Response class from a file name""" mimetype, encoding = self.mimetypes.guess_type(filename) if mimetype and not encoding: return self.from_mimetype(mimetype) else: return Response def from_body(self, body): """Try to guess the appropriate response based on the body content. This method is a bit magic and could be improved in the future, but it's not meant to be used except for special cases where response types cannot be guess using more straightforward methods.""" chunk = body[:5000] chunk = to_bytes(chunk) if not binary_is_text(chunk): return self.from_mimetype('application/octet-stream') elif b"" in chunk.lower(): return self.from_mimetype('text/html') elif b"