Make StructBlock.clean return a StructValue, not a dict - fixes #1355

wagtail/wagtailcore/blocks/struct_block.py

@@ -94,11 +94,11 @@ class BaseStructBlock(Block):
         ])
 
     def clean(self, value):
-        result = {}
+        result = []  # build up a list of (name, value) tuples to be passed to the StructValue constructor
         errors = {}
         for name, val in value.items():
             try:
-                result[name] = self.child_blocks[name].clean(val)
+                result.append((name, self.child_blocks[name].clean(val)))
             except ValidationError as e:
                 errors[name] = ErrorList([e])
 
@@ -107,7 +107,7 @@ class BaseStructBlock(Block):
             # and delegate the errors contained in the 'params' dict to the child blocks instead
             raise ValidationError('Validation error in StructBlock', params=errors)
 
-        return result
+        return StructValue(self, result)
 
     def to_python(self, value):
         # recursively call to_python on children and return as a StructValue

wagtail/wagtailcore/tests/test_blocks.py

@@ -497,6 +497,21 @@ class TestStructBlock(unittest.TestCase):
         self.assertEqual(event['guest_speaker']['first_name'], 'Ed')
         self.assertTrue(isinstance(event['guest_speaker'], blocks.StructValue))
 
+    def test_clean(self):
+        block = blocks.StructBlock([
+            ('title', blocks.CharBlock()),
+            ('link', blocks.URLBlock()),
+        ])
+
+        value = block.to_python({'title': 'Torchbox', 'link': 'http://www.torchbox.com/'})
+        clean_value = block.clean(value)
+        self.assertTrue(isinstance(clean_value, blocks.StructValue))
+        self.assertEqual(clean_value['title'], 'Torchbox')
+
+        value = block.to_python({'title': 'Torchbox', 'link': 'not a url'})
+        with self.assertRaises(ValidationError):
+            block.clean(value)
+
 
 class TestListBlock(unittest.TestCase):
     def test_initialise_with_class(self):