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

@@ -9,16 +9,17 @@
 from collections import namedtuple
 from hashlib import md5, sha1, sha256
 from http.cookies import CookieError, Morsel, SimpleCookie
+from types import MappingProxyType
 
 from multidict import CIMultiDict, CIMultiDictProxy, MultiDict, MultiDictProxy
 from yarl import URL
 
-from . import hdrs, helpers, http, payload
+from . import hdrs, helpers, http, multipart, payload
 from .client_exceptions import (ClientConnectionError, ClientOSError,
                                 ClientResponseError, ContentTypeError,
                                 InvalidURL)
 from .formdata import FormData
-from .helpers import HeadersMixin, TimerNoop, noop
+from .helpers import HeadersMixin, TimerNoop, noop, reify
 from .http import SERVER_SOFTWARE, HttpVersion10, HttpVersion11, PayloadWriter
 from .log import client_logger
 from .streams import FlowControlStreamReader
@@ -33,6 +34,10 @@
 __all__ = ('ClientRequest', 'ClientResponse', 'RequestInfo')
 
 
+ContentDisposition = collections.namedtuple(
+    'ContentDisposition', ('type', 'parameters', 'filename'))
+
+
 RequestInfo = collections.namedtuple(
     'RequestInfo', ('url', 'method', 'headers'))
 
@@ -527,6 +532,7 @@ def __init__(self, method, url, *,
         self._request_info = request_info
         self._timer = timer if timer is not None else TimerNoop()
         self._auto_decompress = auto_decompress
+        self._cache = {}  # reqired for @reify method decorator
 
     @property
     def url(self):
@@ -550,6 +556,16 @@ def _headers(self):
     def request_info(self):
         return self._request_info
 
+    @reify
+    def content_disposition(self):
+        raw = self._headers.get(hdrs.CONTENT_DISPOSITION)
+        if raw is None:
+            return None
+        disposition_type, params = multipart.parse_content_disposition(raw)
+        params = MappingProxyType(params)
+        filename = multipart.content_disposition_filename(params)
+        return ContentDisposition(disposition_type, params, filename)
+
     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
+
+    A :class:`str` instance. Value of Content-Disposition header itself, e.g. ``attachment``.
+
+    .. attribute:: filename
+
+    A :class:`str` instance. Content filename extracted from parameters. May be ``None``.
+
+    .. attribute:: parameters
+
+    Read-only mapping contains all parameters.
 
 Response errors
 ^^^^^^^^^^^^^^^

tests/test_client_response.py

@@ -458,6 +458,42 @@ 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.type
+    assert 'bar' == response.content_disposition.parameters["foo"]
+    assert 'archive.tar.gz' == response.content_disposition.filename
+    with pytest.raises(TypeError):
+        response.content_disposition.parameters["foo"] = "baz"
+
+
+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.type
+    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_content_disposition_cache():
+    response = ClientResponse('get', URL('http://def-cl-resp.org'))
+    response.headers = {'Content-Disposition': 'attachment'}
+    cd = response.content_disposition
+    ClientResponse.headers = {'Content-Disposition': 'spam'}
+    assert cd is response.content_disposition
+
+
 def test_response_request_info():
     url = 'http://def-cl-resp.org'
     headers = {'Content-Type': 'application/json;charset=cp1251'}