Allow referencing models by string representation in SnippetChooserBlock

CHANGELOG.txt

@@ -17,6 +17,7 @@ Changelog
  * Added ability to annotate search results with score (Karl Hobley)
  * Added ability to limit access to form submissions (Mikalai Radchuk)
  * Added the ability to configure the number of days search logs are kept for (Stephen Rice)
+ * `SnippetChooserBlock` now supports passing the model name as a string (Nick Smith)
  * Fix: Migrations for wagtailcore and project template are now reversible (Benjamin Bach)
  * Fix: Migrations no longer depend on wagtailcore and taggit's `__latest__` migration, logically preventing those apps from receiving new migrations (Matt Westcott)
  * Fix: The default image format label text ('Full width', 'Left-aligned', 'Right-aligned') is now localised (Mikalai Radchuk)

docs/releases/1.7.rst

@@ -47,6 +47,7 @@ Minor features
  * Added ability to annotate search results with score - see :ref:`wagtailsearch_annotating_results_with_score` (Karl Hobley)
  * Added ability to limit access to form submissions - see :ref:`filter_form_submissions_for_user` (Mikalai Radchuk)
  * Added the ability to configure the number of days search logs are kept for, through the :ref:`WAGTAILSEARCH_HITS_MAX_AGE <wagtailsearch_hits_max_age>` setting (Stephen Rice)
+ * ``SnippetChooserBlock`` now supports passing the model name as a string (Nick Smith)
 
 
 Bug fixes

wagtail/wagtailsnippets/blocks.py

@@ -3,12 +3,17 @@ from __future__ import absolute_import, unicode_literals
 from django.utils.functional import cached_property
 
 from wagtail.wagtailcore.blocks import ChooserBlock
+from wagtail.wagtailcore.utils import resolve_model_string
 
 
 class SnippetChooserBlock(ChooserBlock):
     def __init__(self, target_model, **kwargs):
         super(SnippetChooserBlock, self).__init__(**kwargs)
-        self.target_model = target_model
+        self._target_model = target_model
+
+    @cached_property
+    def target_model(self):
+        return resolve_model_string(self._target_model)
 
     @cached_property
     def widget(self):

wagtail/wagtailsnippets/tests.py

@@ -690,6 +690,11 @@ class TestSnippetChooserBlock(TestCase):
         # None should deserialize to None
         self.assertEqual(block.to_python(None), None)
 
+    def test_reference_model_by_string(self):
+        block = SnippetChooserBlock('tests.Advert')
+        test_advert = Advert.objects.get(text='test_advert')
+        self.assertEqual(block.to_python(test_advert.id), test_advert)
+
     def test_form_render(self):
         block = SnippetChooserBlock(Advert, help_text="pick an advert, any advert")