Fixed #5387 -- Added is_multipart method to forms. Original patch from Petr Marhhoun. Tests and documentation from Murkt.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@6273 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 12 insertions, 0 deletions

diff --git a/django/newforms/forms.py b/django/newforms/forms.py
index ab8729be65..2b1caddeda 100644
--- a/django/newforms/forms.py
+++ b/django/newforms/forms.py
@@ -212,6 +212,16 @@ class BaseForm(StrAndUnicode):
         """
         return self.cleaned_data
 
+    def is_multipart(self):
+        """
+        Returns True if the form needs to be multipart-encrypted, i.e. it has
+        FileInput. Otherwise, False.
+        """
+        for field in self.fields.values():
+            if field.widget.needs_multipart_form:
+                return True
+        return False
+
 class Form(BaseForm):
     "A collection of Fields, plus their associated data."
     # This is a separate class from BaseForm in order to abstract the way
diff --git a/django/newforms/widgets.py b/django/newforms/widgets.py
index f985124389..0e7752499e 100644
--- a/django/newforms/widgets.py
+++ b/django/newforms/widgets.py
@@ -24,6 +24,7 @@ __all__ = (
 
 class Widget(object):
     is_hidden = False          # Determines whether this corresponds to an <input type="hidden">.
+    needs_multipart_form = False # Determines does this widget need multipart-encrypted form
 
     def __init__(self, attrs=None):
         if attrs is not None:
@@ -120,6 +121,7 @@ class MultipleHiddenInput(HiddenInput):
 
 class FileInput(Input):
     input_type = 'file'
+    needs_multipart_form = True
 
     def render(self, name, value, attrs=None):
         return super(FileInput, self).render(name, None, attrs=attrs)