Merge branch 'jossingram-snippet_chooser_panel'

CHANGELOG.txt

@@ -26,6 +26,7 @@ Changelog
  * Added database indexes on PageRevision and Image to improve performance on large sites
  * Search in page chooser now uses Wagtail's search framework, to order results by relevance
  * `PageChooserPanel` now supports passing a list (or tuple) of accepted page types
+ * The snippet type parameter of `SnippetChooserPanel` can now be omitted, or passed as a model name string rather than a model class
  * Fix: Text areas in the non-default tab of the page editor now resize to the correct height
  * Fix: Tabs in "insert link" modal in the rich text editor no longer disappear (Tim Heap)
  * Fix: H2 elements in rich text fields were accidentally given a click() binding when put insite a collapsible multi field panel

docs/advanced_topics/customisation/page_editing_interface.rst

@@ -23,7 +23,7 @@ As standard, Wagtail organises panels into three tabs: 'Content', 'Promote' and
             FieldPanel('body', classname="full"),
         ]
         sidebar_content_panels = [
-            SnippetChooserPanel('advert', Advert),
+            SnippetChooserPanel('advert'),
             InlinePanel('related_links', label="Related links"),
         ]
 

docs/reference/pages/editing_api.rst

@@ -233,9 +233,13 @@ DocumentChooserPanel
 SnippetChooserPanel
 -------------------
 
-.. class:: wagtail.wagtailsnippets.edit_handlers.SnippetChooserPanel(field_name, model)
+.. versionchanged:: 1.1
 
-    Snippets are vanilla Django models you create yourself without a Wagtail-provided base class. So using them as a field in a page requires specifying your own ``appname.modelname``. A chooser, ``SnippetChooserPanel``, is provided which takes the field name and snippet class.
+    Before Wagtail 1.1, it was necessary to pass the snippet model class as a second parameter to ``SnippetChooserPanel``. This is now automatically picked up from the field.
+
+.. class:: wagtail.wagtailsnippets.edit_handlers.SnippetChooserPanel(field_name, snippet_type=None)
+
+    Snippets are vanilla Django models you create yourself without a Wagtail-provided base class. A chooser, ``SnippetChooserPanel``, is provided which takes the field name as an argument.
 
     .. code-block:: python
 
@@ -251,7 +255,7 @@ SnippetChooserPanel
           )
 
           content_panels = Page.content_panels + [
-              SnippetChooserPanel('advert', Advert),
+              SnippetChooserPanel('advert'),
           ]
 
     See :ref:`snippets` for more information.

docs/releases/1.1.rst

@@ -63,6 +63,7 @@ Minor features
  * Added database indexes on PageRevision and Image to improve performance on large sites
  * Search in page chooser now uses Wagtail's search framework, to order results by relevance
  * ``PageChooserPanel`` now supports passing a list (or tuple) of accepted page types
+ * The snippet type parameter of ``SnippetChooserPanel`` can now be omitted, or passed as a model name string rather than a model class
 
 Bug fixes
 ~~~~~~~~~

docs/topics/snippets.rst

@@ -112,7 +112,7 @@ In the above example, the list of adverts is a fixed list, displayed as part of
   
   
   BookPage.content_panels = [
-      SnippetChooserPanel('advert', Advert),
+      SnippetChooserPanel('advert'),
       # ...
   ]
 
@@ -142,7 +142,7 @@ To attach multiple adverts to a page, the ``SnippetChooserPanel`` can be placed
           verbose_name_plural = "Advert Placements"
   
       panels = [
-          SnippetChooserPanel('advert', Advert),
+          SnippetChooserPanel('advert'),
       ]
   
       def __str__(self):              # __unicode__ on Python 2

wagtail/wagtailsnippets/edit_handlers.py

@@ -4,40 +4,62 @@ from django.template.loader import render_to_string
 from django.contrib.contenttypes.models import ContentType
 from django.utils.safestring import mark_safe
 from django.utils.encoding import force_text
+from django.core.exceptions import ImproperlyConfigured
 
 from wagtail.wagtailadmin.edit_handlers import BaseChooserPanel
+from wagtail.wagtailcore.utils import resolve_model_string
 from .widgets import AdminSnippetChooser
 
 
 class BaseSnippetChooserPanel(BaseChooserPanel):
     object_type_name = 'item'
 
-    _content_type = None
+    _target_model = None
+    _target_content_type = None
 
     @classmethod
     def widget_overrides(cls):
         return {cls.field_name: AdminSnippetChooser(
-            content_type=cls.content_type(), snippet_type_name=cls.snippet_type_name)}
+            content_type=cls.target_content_type(), snippet_type_name=cls.get_snippet_type_name())}
 
     @classmethod
-    def content_type(cls):
-        if cls._content_type is None:
-            # TODO: infer the content type by introspection on the foreign key rather than having to pass it explicitly
-            cls._content_type = ContentType.objects.get_for_model(cls.snippet_type)
+    def target_model(cls):
+        if cls._target_model is None:
+            if cls.snippet_type:
+                try:
+                    cls._target_model = resolve_model_string(cls.snippet_type)
+                except LookupError:
+                    raise ImproperlyConfigured("{0}.snippet_type must be of the form 'app_label.model_name', given {1!r}".format(
+                        cls.__name__, cls.snippet_type))
+                except ValueError:
+                    raise ImproperlyConfigured("{0}.snippet_type refers to model {1!r} that has not been installed".format(
+                        cls.__name__, cls.snippet_type))
+            else:
+                cls._target_model = cls.model._meta.get_field(cls.field_name).rel.to
 
-        return cls._content_type
+        return cls._target_model
+
+    @classmethod
+    def target_content_type(cls):
+        if cls._target_content_type is None:
+            cls._target_content_type = ContentType.objects.get_for_model(cls.target_model())
+        return cls._target_content_type
 
     def render_as_field(self):
         instance_obj = self.get_chosen_item()
         return mark_safe(render_to_string(self.field_template, {
             'field': self.bound_field,
             self.object_type_name: instance_obj,
-            'snippet_type_name': self.snippet_type_name,
+            'snippet_type_name': self.get_snippet_type_name(),
         }))
 
+    @classmethod
+    def get_snippet_type_name(cls):
+        return force_text(cls.target_model()._meta.verbose_name)
+
 
 class SnippetChooserPanel(object):
-    def __init__(self, field_name, snippet_type):
+    def __init__(self, field_name, snippet_type=None):
         self.field_name = field_name
         self.snippet_type = snippet_type
 
@@ -45,6 +67,5 @@ class SnippetChooserPanel(object):
         return type(str('_SnippetChooserPanel'), (BaseSnippetChooserPanel,), {
             'model': model,
             'field_name': self.field_name,
-            'snippet_type_name': force_text(self.snippet_type._meta.verbose_name),
             'snippet_type': self.snippet_type,
         })

wagtail/wagtailsnippets/tests.py

@@ -3,11 +3,13 @@ from django.core.urlresolvers import reverse
 from django.test.utils import override_settings
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Permission
+from django.core.exceptions import ImproperlyConfigured
 
 from wagtail.tests.utils import WagtailTestUtils
 from wagtail.tests.testapp.models import Advert, SnippetChooserModel
 from wagtail.tests.snippets.models import AlphaSnippet, ZuluSnippet, RegisterDecorator, RegisterFunction, SearchableSnippet
 from wagtail.wagtailsnippets.models import register_snippet, SNIPPET_MODELS
+from wagtail.wagtailsnippets.edit_handlers import SnippetChooserPanel
 
 from wagtail.wagtailsnippets.views.snippets import (
     get_snippet_edit_handler
@@ -198,7 +200,7 @@ class TestSnippetDelete(TestCase, WagtailTestUtils):
         self.assertEqual(response.status_code, 200)
 
     def test_delete_post(self):
-        post_data = {'foo': 'bar'} # For some reason, this test doesn't work without a bit of POST data
+        post_data = {'foo': 'bar'}  # For some reason, this test doesn't work without a bit of POST data
         response = self.client.post(reverse('wagtailsnippets:delete', args=('tests', 'advert', self.test_snippet.id, )), post_data)
 
         # Should be redirected to explorer page
@@ -231,12 +233,51 @@ class TestSnippetChooserPanel(TestCase):
                          '_SnippetChooserPanel')
 
     def test_render_as_field(self):
-        self.assertTrue(self.advert_text in self.snippet_chooser_panel.render_as_field())
+        field_html = self.snippet_chooser_panel.render_as_field()
+        self.assertIn(self.advert_text, field_html)
+        self.assertIn("Choose advert", field_html)
+        self.assertIn("Choose another advert", field_html)
 
     def test_render_js(self):
         self.assertIn('createSnippetChooser("id_advert", "tests/advert");',
                       self.snippet_chooser_panel.render_as_field())
 
+    def test_target_content_type_from_string(self):
+        result = SnippetChooserPanel(
+            'advert',
+            'tests.advert'
+        ).bind_to_model(SnippetChooserModel).target_content_type()
+        self.assertEqual(result.name, 'advert')
+
+    def test_target_content_type_from_model(self):
+        result = SnippetChooserPanel(
+            'advert',
+            Advert
+        ).bind_to_model(SnippetChooserModel).target_content_type()
+        self.assertEqual(result.name, 'advert')
+
+    def test_target_content_type_autodetected(self):
+        result = SnippetChooserPanel(
+            'advert'
+        ).bind_to_model(SnippetChooserModel).target_content_type()
+        self.assertEqual(result.name, 'advert')
+
+    def test_target_content_type_malformed_type(self):
+        result = SnippetChooserPanel(
+            'advert',
+            'snowman'
+        ).bind_to_model(SnippetChooserModel)
+        self.assertRaises(ImproperlyConfigured,
+                          result.target_content_type)
+
+    def test_target_content_type_nonexistent_type(self):
+        result = SnippetChooserPanel(
+            'advert',
+            'snowman.lorry'
+        ).bind_to_model(SnippetChooserModel)
+        self.assertRaises(ImproperlyConfigured,
+                          result.target_content_type)
+
 
 class TestSnippetRegistering(TestCase):
     def test_register_function(self):