Content-Disposition fast access in ClientResponse

Add ContentDisposition class and content_disposition property

Partially implements aio-libs#1670

CHANGES/2455.feature

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

aiohttp/helpers.py

@@ -4,6 +4,7 @@
 import base64
 import binascii
 import cgi
+import collections
 import datetime
 import functools
 import inspect
@@ -41,6 +42,10 @@
 TOKEN = CHAR ^ CTL ^ SEPARATORS
 
 
+ContentDisposition = collections.namedtuple(
+    'ContentDisposition', ('value', 'parameters', 'filename'))
+
+
 class _BaseCoroMixin(Coroutine):
 
     __slots__ = ('_coro')
@@ -703,6 +708,7 @@ class HeadersMixin:
 
     _content_type = None
     _content_dict = None
+    _content_disposition = False
     _stored_content_type = sentinel
 
     def _parse_content_type(self, raw):
@@ -714,6 +720,18 @@ def _parse_content_type(self, raw):
         else:
             self._content_type, self._content_dict = cgi.parse_header(raw)
 
+    def _parse_content_disposition(self, _CONTENT_DISPOSITION):
+        from . import multipart
+        raw = self._headers.get(_CONTENT_DISPOSITION)
+        if raw is None:
+            self._content_disposition = None
+        else:
+            value, params = multipart.parse_content_disposition(raw)
+            filename = multipart.content_disposition_filename(params)
+            self._content_disposition = ContentDisposition(value, params,
+                                                           filename)
+        return self._content_disposition
+
     @property
     def content_type(self, *, _CONTENT_TYPE=hdrs.CONTENT_TYPE):
         """The value of content part for Content-Type HTTP header."""
@@ -737,3 +755,10 @@ def content_length(self, *, _CONTENT_LENGTH=hdrs.CONTENT_LENGTH):
 
         if content_length:
             return int(content_length)
+
+    @property
+    def content_disposition(self, *, header=hdrs.CONTENT_DISPOSITION):
+        """The value of Content-Disposition HTTP header."""
+        if self._content_disposition == False:
+            self._parse_content_disposition(header)
+        return self._content_disposition

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'}