Fix update_index throwing AttributeError when value is None (#5757)

CHANGELOG.txt

@@ -34,6 +34,7 @@ Changelog
  * Fix: `file_size` and `file_hash` not updated when Document file changed (Andreas Bernacca)
  * Fix: Fixed order of URLs in project template so that static / media URLs are not blocked (Nick Smith)
  * Fix: Added verbose_name_plural for form submission model (Janneke Janssen)
+ * Fix: Prevent `update_index` failures and incorrect front-end rendering on blank `TableBlock` (Carlo Ascani)
 
 
 2.7.1 (08.01.2020)

docs/releases/2.8.rst

@@ -59,6 +59,7 @@ Bug fixes
  * ``file_size`` and ``file_hash`` not updated when Document file changed (Andreas Bernacca)
  * Fixed order of URLs in project template so that static / media URLs are not blocked (Nick Smith)
  * Added verbose_name_plural for form submission model (Janneke Janssen)
+ * Prevent ``update_index`` failures and incorrect front-end rendering on blank ``TableBlock`` (Carlo Ascani)
 
 
 Upgrade considerations

wagtail/contrib/table_block/blocks.py

@@ -83,8 +83,9 @@ class TableBlock(FieldBlock):
 
     def get_searchable_content(self, value):
         content = []
-        for row in value.get('data', []):
-            content.extend([v for v in row if v])
+        if value:
+            for row in value.get('data', []):
+                content.extend([v for v in row if v])
         return content
 
     def render(self, value, context=None):
@@ -116,7 +117,7 @@ class TableBlock(FieldBlock):
 
             return render_to_string(template, new_context)
         else:
-            return self.render_basic(value, context=context)
+            return self.render_basic(value or "", context=context)
 
     @property
     def media(self):

wagtail/contrib/table_block/tests.py

@@ -224,6 +224,12 @@ class TestTableBlock(TestCase):
         content = block.get_searchable_content(value)
         self.assertEqual(content, ['Test 1', 'Test 2', 'Test 3', 'Bar', 'Foo', ])
 
+    def test_searchable_content_for_null_block(self):
+        value = None
+        block = TableBlock()
+        content = block.get_searchable_content(value)
+        self.assertEqual(content, [])
+
     def test_render_with_extra_context(self):
         """
         Test that extra context variables passed in block.render are passed through
@@ -264,6 +270,18 @@ class TestTableBlock(TestCase):
         self.assertHTMLEqual(result, expected)
         self.assertIn('Test 2', result)
 
+    def test_empty_table_block_is_not_rendered(self):
+        """
+        Test an empty table is not rendered.
+        """
+        value = None
+        block = TableBlock()
+        result = block.render(value)
+        expected = ''
+
+        self.assertHTMLEqual(result, expected)
+        self.assertNotIn('None', result)
+
 
 class TestTableBlockForm(WagtailTestUtils, SimpleTestCase):