From 46542cdc3c80f2484991e2f523677fc2b0786261 Mon Sep 17 00:00:00 2001
From: Benoit Bryon <benoit@marmelune.net>
Date: Mon, 19 Nov 2012 14:39:30 +0100
Subject: [PATCH] Refs #3 - Introduced base decorators and middlewares.

---
 django_downloadview/decorators.py  | 27 +++++++++++++++++++++++++++
 django_downloadview/middlewares.py | 22 ++++++++++++++++++++++
 django_downloadview/response.py    | 10 ++++++++++
 docs/api/django_downloadview.txt   | 24 ++++++++++++++++++++++++
 4 files changed, 83 insertions(+)
 create mode 100644 django_downloadview/decorators.py
 create mode 100644 django_downloadview/middlewares.py

diff --git a/django_downloadview/decorators.py b/django_downloadview/decorators.py
new file mode 100644
index 0000000..3e93ec3
--- /dev/null
+++ b/django_downloadview/decorators.py
@@ -0,0 +1,27 @@
+"""View decorators."""
+
+
+class DownloadDecorator(object):
+    """View decorator factory to apply middleware to ``view_func`` response.
+
+    Middleware instance is built from ``middleware_factory`` with ``*args`` and
+    ``**kwargs``. Middleware factory is typically a class, such as some
+    :py:class:`django_downloadview.middlewares.XAccelMiddleware` subclass.
+
+    Response is built from view, then the middleware's ``process_response``
+    method is applied on response.
+
+    """
+    def __init__(self, middleware_factory):
+        """Create a download view decorator."""
+        self.middleware_factory = middleware_factory
+
+    def __call__(self, view_func, *middleware_args, **middleware_kwargs):
+        """Return ``view_func`` decorated with response middleware."""
+        def decorated(request, *view_args, **view_kwargs):
+            """Return view's response modified by middleware."""
+            response = view_func(request, *view_args, **view_kwargs)
+            middleware = self.middleware_factory(*middleware_args,
+                                                 **middleware_kwargs)
+            return middleware.process_response(request, response)
+        return decorated
diff --git a/django_downloadview/middlewares.py b/django_downloadview/middlewares.py
new file mode 100644
index 0000000..d0c2cbb
--- /dev/null
+++ b/django_downloadview/middlewares.py
@@ -0,0 +1,22 @@
+"""Base material for download middlewares."""
+from django_downloadview.response import is_download_response
+
+
+class BaseDownloadMiddleware(object):
+    """Base (abstract) Django middleware that process download responses.
+
+    Subclasses **must** implement ``process_download_response`` method.
+
+    """
+    def is_download_response(self, response):
+        """Return True if ``response`` can be considered as a file download."""
+        return is_download_response(response)
+
+    def process_response(self, request, response):
+        """Call ``process_download_response()`` if ``response`` is download."""
+        if self.is_download_response(response):
+            return self.process_download_response(request, response)
+
+    def process_download_response(self, request, response):
+        """Handle file download response."""
+        raise NotImplementedError()
diff --git a/django_downloadview/response.py b/django_downloadview/response.py
index 592f41d..9f6c2c5 100644
--- a/django_downloadview/response.py
+++ b/django_downloadview/response.py
@@ -50,3 +50,13 @@ class DownloadResponse(HttpResponse):
         if expires:
             self['Expires'] = expires
         self['Content-Disposition'] = 'attachment; filename=%s' % basename
+
+
+def is_download_response(response):
+    """Return ``True`` if ``response`` is a download response.
+
+    Current implementation returns True if ``response`` is an instance of
+    :py:class:`django_downloadview.DownloadResponse`.
+
+    """
+    return isinstance(response, DownloadResponse)
diff --git a/docs/api/django_downloadview.txt b/docs/api/django_downloadview.txt
index a6255ec..4b70ab3 100644
--- a/docs/api/django_downloadview.txt
+++ b/docs/api/django_downloadview.txt
@@ -9,6 +9,30 @@ django_downloadview Package
     :undoc-members:
     :show-inheritance:
 
+:mod:`decorators` Module
+------------------------
+
+.. automodule:: django_downloadview.decorators
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
+:mod:`middlewares` Module
+-------------------------
+
+.. automodule:: django_downloadview.middlewares
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
+:mod:`response` Module
+----------------------
+
+.. automodule:: django_downloadview.response
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
 :mod:`views` Module
 -------------------