implement value_omitted_from_data function inside widget

Author: mehdipourfar

postgres_composite_types/forms.py

@@ -218,6 +218,12 @@ def value_from_datadict(self, data, files, name):
             for subname, widget in self.widgets.items()
         }
 
+    def value_omitted_from_data(self, data, files, name):
+        for key in data:
+            if key.startswith('{}-'.format(name)):
+                return False
+        return True
+
     def id_for_label(self, id_):
         """
         Wrapper around the field widget's `id_for_label` method.

tests/test_forms.py

@@ -122,6 +122,17 @@ def test_null_initial_data(self):
             """,
             str(form['simple_field']))
 
+    def test_value_omission_check_inside_widget(self):
+        form = self.SimpleForm()
+        widget = form.fields['simple_field'].widget
+        self.assertFalse(
+            widget.value_omitted_from_data(
+                data=self.simple_valid_data,
+                files=[],
+                name='simple_field',
+            )
+        )
+
     # pylint:disable=invalid-name
     def assertHTMLContains(self, text, content, count=None, msg=None):
         """