Content-Disposition fast access in ClientResponse

Add ContentDisposition class and content_disposition property

Partially implements #1670

CHANGES/2455.feature

@@ -0,0 +1 @@
+Content-Disposition fast access in ClientResponse

aiohttp/client_reqrep.py

@@ -7,13 +7,14 @@
 import traceback
 import warnings
 from collections import namedtuple
+from types import MappingProxyType
 from hashlib import md5, sha1, sha256
 from http.cookies import CookieError, Morsel, SimpleCookie
 
 from multidict import CIMultiDict, CIMultiDictProxy, MultiDict, MultiDictProxy
 from yarl import URL
 
-from . import hdrs, helpers, http, payload
+from . import hdrs, helpers, http, payload, multipart
 from .client_exceptions import (ClientConnectionError, ClientOSError,
                                 ClientResponseError, ContentTypeError,
                                 InvalidURL)
@@ -33,6 +34,10 @@
 __all__ = ('ClientRequest', 'ClientResponse', 'RequestInfo')
 
 
+ContentDisposition = collections.namedtuple(
+    'ContentDisposition', ('value', 'parameters', 'filename'))
+
+
 RequestInfo = collections.namedtuple(
     'RequestInfo', ('url', 'method', 'headers'))
 
@@ -500,6 +505,7 @@ class ClientResponse(HeadersMixin):
     raw_headers = None  # Response raw headers, a sequence of pairs
 
     _connection = None  # current connection
+    _content_disposition = False  # content disposition cache
     flow_control_class = FlowControlStreamReader  # reader flow control
     _reader = None     # input stream
     _source_traceback = None
@@ -550,6 +556,20 @@ def _headers(self):
     def request_info(self):
         return self._request_info
 
+    @property
+    def content_disposition(self):
+        if self._content_disposition is False:
+            raw = self._headers.get(hdrs.CONTENT_DISPOSITION)
+            if raw is None:
+                self._content_disposition = None
+            else:
+                value, params = multipart.parse_content_disposition(raw)
+                params = MappingProxyType(params)
+                filename = multipart.content_disposition_filename(params)
+                self._content_disposition = ContentDisposition(value, params,
+                                                               filename)
+        return self._content_disposition
+
     def _post_init(self, loop, session):
         self._loop = loop
         self._session = session  # store a reference to session #1985

docs/client_reference.rst

@@ -1109,13 +1109,20 @@ Response object
 
    .. attribute:: charset
 
-   Read-only property that specifies the *encoding* for the request's BODY.
+      Read-only property that specifies the *encoding* for the request's BODY.
 
       The value is parsed from the *Content-Type* HTTP header.
 
       Returns :class:`str` like ``'utf-8'`` or ``None`` if no *Content-Type*
       header present in HTTP headers or it has no charset information.
 
+   .. attribute:: content_disposition
+
+      Read-only property that specified the *Content-Disposition* HTTP header.
+
+      Instance of :class:`ContentDisposition` or ``None`` if no *Content-Disposition*
+      header present in HTTP headers.
+
    .. attribute:: history
 
       A :class:`~collections.abc.Sequence` of :class:`ClientResponse`
@@ -1561,6 +1568,21 @@ All exceptions are available as members of *aiohttp* module.
 
       Invalid URL, :class:`yarl.URL` instance.
 
+.. class:: ContentDisposition
+
+    Represent Content-Disposition header
+
+    .. attribute:: value
+
+    Value of Content-Disposition header itself, e.g. ``attachment``.
+
+    .. attribute:: filename
+
+    Content filename extracted from parameters. May be ``None``.
+
+    .. attribute:: parameters
+
+    A :class:`dict` instance contains all parameters.
 
 Response errors
 ^^^^^^^^^^^^^^^

tests/test_client_response.py

@@ -458,6 +458,32 @@ def test_charset_no_charset():
     assert response.charset is None
 
 
+def test_content_disposition_full():
+    response = ClientResponse('get', URL('http://def-cl-resp.org'))
+    response.headers = {'Content-Disposition':
+                        'attachment; filename="archive.tar.gz"; foo=bar'}
+
+    assert 'attachment' == response.content_disposition.value
+    assert 'bar' == response.content_disposition.parameters["foo"]
+    assert 'archive.tar.gz' == response.content_disposition.filename
+
+
+def test_content_disposition_no_parameters():
+    response = ClientResponse('get', URL('http://def-cl-resp.org'))
+    response.headers = {'Content-Disposition': 'attachment'}
+
+    assert 'attachment' == response.content_disposition.value
+    assert response.content_disposition.filename is None
+    assert {} == response.content_disposition.parameters
+
+
+def test_content_disposition_no_header():
+    response = ClientResponse('get', URL('http://def-cl-resp.org'))
+    response.headers = {}
+
+    assert response.content_disposition is None
+
+
 def test_response_request_info():
     url = 'http://def-cl-resp.org'
     headers = {'Content-Type': 'application/json;charset=cp1251'}