Merge pull request #806 from wronglink/master

Added FileUploadParser

docs/api-guide/parsers.md

@@ -102,6 +102,28 @@ You will typically want to use both `FormParser` and `MultiPartParser` together
 
 **.media_type**: `multipart/form-data`
 
+## FileUploadParser
+
+Parses raw file upload content. Returns a `DataAndFiles` object. Since we expect the whole request body to be a file content `request.DATA` will be None, and `request.FILES` will contain the only one key `'file'` matching the uploaded file.
+
+The `filename` property of uploaded file would be set to the result of `.get_filename()` method. By default it tries first to take it's value from the `filename` URL kwarg, and then from `Content-Disposition` HTTP header. You can implement other behaviour be overriding this method.
+
+Note that since this parser's `media_type` matches every HTTP request it imposes restrictions on usage in combination with other parsers for the same API view.
+
+Basic usage expamle:
+
+    class FileUploadView(views.APIView):
+        parser_classes = (FileUploadParser,)
+
+        def put(self, request, filename, format=None):
+            file_obj = request.FILES['file']
+            # ...
+            # do some staff with uploaded file
+            # ...
+            return Response(status=204)
+
+**.media_type**: `*/*`
+
 ---
 
 # Custom parsers
@@ -145,35 +167,6 @@ The following is an example plaintext parser that will populate the `request.DAT
         """
         return stream.read()
 
-## Uploading file content
-
-If your custom parser needs to support file uploads, you may return a `DataAndFiles` object from the `.parse()` method.  `DataAndFiles` should be instantiated with two arguments.  The first argument will be used to populate the `request.DATA` property, and the second argument will be used to populate the `request.FILES` property.
-
-For example:
-
-    class SimpleFileUploadParser(BaseParser):
-        """
-        A naive raw file upload parser.
-        """
-        media_type = '*/*'  # Accept anything
-
-        def parse(self, stream, media_type=None, parser_context=None):
-            content = stream.read()
-            name = 'example.dat'
-            content_type = 'application/octet-stream'
-            size = len(content)
-            charset = 'utf-8'
-
-            # Write a temporary file based on the request content
-            temp = tempfile.NamedTemporaryFile(delete=False)
-            temp.write(content)
-            uploaded = UploadedFile(temp, name, content_type, size, charset)
-
-            # Return the uploaded file
-            data = {}
-            files = {name: uploaded}
-            return DataAndFiles(data, files)
-
 ---
 
 # Third party packages

rest_framework/parsers.py

@@ -6,9 +6,10 @@ on the request, such as form content or json encoded data.
 """
 from __future__ import unicode_literals
 from django.conf import settings
+from django.core.files.uploadhandler import StopFutureHandlers
 from django.http import QueryDict
 from django.http.multipartparser import MultiPartParser as DjangoMultiPartParser
-from django.http.multipartparser import MultiPartParserError
+from django.http.multipartparser import MultiPartParserError, parse_header, ChunkIter
 from rest_framework.compat import yaml, etree
 from rest_framework.exceptions import ParseError
 from rest_framework.compat import six
@@ -205,3 +206,83 @@ class XMLParser(BaseParser):
             pass
 
         return value
+
+
+class FileUploadParser(BaseParser):
+    """
+    Parser for file upload data.
+    """
+    media_type = '*/*'
+
+    def parse(self, stream, media_type=None, parser_context=None):
+        """
+        Returns a DataAndFiles object.
+
+        `.data` will be None (we expect request body to be a file content).
+        `.files` will be a `QueryDict` containing one 'file' elemnt - a parsed file.
+        """
+
+        parser_context = parser_context or {}
+        request = parser_context['request']
+        encoding = parser_context.get('encoding', settings.DEFAULT_CHARSET)
+        meta = request.META
+        upload_handlers = request.upload_handlers
+        filename = self.get_filename(stream, media_type, parser_context)
+
+        content_type = meta.get('HTTP_CONTENT_TYPE', meta.get('CONTENT_TYPE', ''))
+        try:
+            content_length = int(meta.get('HTTP_CONTENT_LENGTH', meta.get('CONTENT_LENGTH', 0)))
+        except (ValueError, TypeError):
+            content_length = None
+
+        # See if the handler will want to take care of the parsing.
+        for handler in upload_handlers:
+            result = handler.handle_raw_input(None,
+                                              meta,
+                                              content_length,
+                                              None,
+                                              encoding)
+            if result is not None:
+                return DataAndFiles(None, {'file': result[1]})
+
+        possible_sizes = [x.chunk_size for x in upload_handlers if x.chunk_size]
+        chunk_size = min([2**31-4] + possible_sizes)
+        chunks = ChunkIter(stream, chunk_size)
+        counters = [0] * len(upload_handlers)
+
+        for handler in upload_handlers:
+            try:
+                handler.new_file(None, filename, content_type, content_length, encoding)
+            except StopFutureHandlers:
+                break
+
+        for chunk in chunks:
+            for i, handler in enumerate(upload_handlers):
+                chunk_length = len(chunk)
+                chunk = handler.receive_data_chunk(chunk, counters[i])
+                counters[i] += chunk_length
+                if chunk is None:
+                    # If the chunk received by the handler is None, then don't continue.
+                    break
+
+        for i, handler in enumerate(upload_handlers):
+            file_obj = handler.file_complete(counters[i])
+            if file_obj:
+                return DataAndFiles(None, {'file': file_obj})
+        raise ParseError("FileUpload parse error - none of upload handlers can handle the stream")
+
+    def get_filename(self, stream, media_type, parser_context):
+        """
+        Detects the uploaded file name. First searches a 'filename' url kwarg.
+        Then tries to parse Content-Disposition header.
+        """
+        try:
+            return parser_context['kwargs']['filename']
+        except KeyError:
+            pass
+        try:
+            meta = parser_context['request'].META
+            disposition = parse_header(meta['HTTP_CONTENT_DISPOSITION'])
+            return disposition[1]['filename']
+        except (AttributeError, KeyError):
+            pass

rest_framework/tests/parsers.py

@@ -1,10 +1,11 @@
 from __future__ import unicode_literals
 from rest_framework.compat import StringIO
 from django import forms
+from django.core.files.uploadhandler import MemoryFileUploadHandler
 from django.test import TestCase
 from django.utils import unittest
 from rest_framework.compat import etree
-from rest_framework.parsers import FormParser
+from rest_framework.parsers import FormParser, FileUploadParser
 from rest_framework.parsers import XMLParser
 import datetime
 
@@ -82,3 +83,33 @@ class TestXMLParser(TestCase):
         parser = XMLParser()
         data = parser.parse(self._complex_data_input)
         self.assertEqual(data, self._complex_data)
+
+
+class TestFileUploadParser(TestCase):
+    def setUp(self):
+        class MockRequest(object):
+            pass
+        from io import BytesIO
+        self.stream = BytesIO(
+            "Test text file".encode('utf-8')
+        )
+        request = MockRequest()
+        request.upload_handlers = (MemoryFileUploadHandler(),)
+        request.META = {
+            'HTTP_CONTENT_DISPOSITION': 'Content-Disposition: inline; filename=file.txt'.encode('utf-8'),
+            'HTTP_CONTENT_LENGTH': 14,
+        }
+        self.parser_context = {'request': request, 'kwargs': {}}
+
+    def test_parse(self):
+        """ Make sure the `QueryDict` works OK """
+        parser = FileUploadParser()
+        self.stream.seek(0)
+        data_and_files = parser.parse(self.stream, None, self.parser_context)
+        file_obj = data_and_files.files['file']
+        self.assertEqual(file_obj._size, 14)
+
+    def test_get_filename(self):
+        parser = FileUploadParser()
+        filename = parser.get_filename(self.stream, None, self.parser_context)
+        self.assertEqual(filename, 'file.txt'.encode('utf-8'))