Ticket #4979: 4979-admin-file-deletion.2.diff

django/db/models/fields/files.py

@@ -188 +188 @@
         return os.path.join(self.get_directory_name(), self.get_filename(filename))
 
     def save_form_data(self, instance, data):
-        if data and isinstance(data, UploadedFile):
+        if data is False:
+            getattr(instance, self.name).delete(save=False)
+        elif data and isinstance(data, UploadedFile):
             getattr(instance, self.name).save(data.name, data, save=False)
 
     def formfield(self, **kwargs):

django/forms/fields.py

@@ -453 +453 @@
 
     def clean(self, data, initial=None):
         super(FileField, self).clean(initial or data)
-        if not self.required and data in EMPTY_VALUES:
-            return None
+        if not self.required:
+            if data is False:
+                return False
+            elif data in EMPTY_VALUES:
+                return None
         elif not data and initial:
             return initial
 
@@ -483 +486 @@
         PNG, possibly others -- whatever the Python Imaging Library supports).
         """
         f = super(ImageField, self).clean(data, initial)
-        if f is None:
-            return None
+        if not f:
+            return f
         elif not data and initial:
             return initial
         from PIL import Image

django/contrib/admin/options.py

@@ -105 +105 @@
             kwargs['widget'] = widgets.AdminTextInputWidget
             return db_field.formfield(**kwargs)
     
-        # For FileFields and ImageFields add a link to the current file.
+        # For FileFields and ImageFields add a link to the current file and a delete option where appropriate
         if isinstance(db_field, models.ImageField) or isinstance(db_field, models.FileField):
-            kwargs['widget'] = widgets.AdminFileWidget
+            if db_field.blank:
+                kwargs['widget'] = widgets.AdminClearableFileWidget
+            else:
+                kwargs['widget'] = widgets.AdminFileWidget
             return db_field.formfield(**kwargs)
 
         # For ForeignKey or ManyToManyFields, use a special widget.

django/contrib/admin/widgets.py

@@ -95 +95 @@
         output.append(super(AdminFileWidget, self).render(name, value, attrs))
         return mark_safe(u''.join(output))
 
+
+class AdminClearableFileWidget(AdminFileWidget):
+    def render(self, name, value, attrs=None):
+        output = [super(AdminClearableFileWidget, self).render(name, value, attrs)]
+        if value and hasattr(value, "url"):
+            checkbox = forms.CheckboxInput()
+            checkbox_name = name + '-delete'
+            output.append(' ')
+            output.append(_('Delete?'))
+            output.append(checkbox.render(checkbox_name, False, attrs))
+        return mark_safe(u''.join(output))
+
+    def value_from_datadict(self, data, files, name):
+        """Checks to see whether a file was uploaded and if not,
+        whether the Delete checkbox was set.
+
+        To allow _has_changed to determine between no change and
+        and delete request, no change will return None and deletion
+        will return False.
+        """
+        try:
+            return files[name]
+        except KeyError:
+            if (name + '-delete') in data:
+                return False
+            return None
+
+
 class ForeignKeyRawIdWidget(forms.TextInput):
     """
     A Widget for displaying ForeignKeys in the "raw_id" interface rather than