Avoid calling versioned_static from static form media definitions (#5644)

* Avoid calling versioned_static from static form media definitions

Fixes #5632

Defining media definitions with `class Media:` means that those lines are evaluated on application startup; this means that they cannot contain calls to the Django static file finder, because ManifestStaticFilesStorage doesn't work until collectstatic has completed. Fix this by making those definitions into `def media(self):` methods.

* Add test to confirm that inheritance still works with dynamic form media definitions

wagtail/admin/rich_text/editors/hallo.py

@@ -68,12 +68,18 @@ class HalloListPlugin(HalloPlugin):
         plugins[self.name]['lists'][self.list_type] = True
 
 
+class HalloRequireParagraphsPlugin(HalloPlugin):
+    @property
+    def media(self):
+        return Media(js=[
+            versioned_static('wagtailadmin/js/hallo-plugins/hallo-requireparagraphs.js'),
+        ]) + super().media
+
+
 # Plugins which are always imported, and cannot be enabled/disabled via 'features'
 CORE_HALLO_PLUGINS = [
     HalloPlugin(name='halloreundo', order=50),
-    HalloPlugin(name='hallorequireparagraphs', js=[
-        versioned_static('wagtailadmin/js/hallo-plugins/hallo-requireparagraphs.js'),
-    ]),
+    HalloRequireParagraphsPlugin(name='hallorequireparagraphs'),
     HalloHeadingPlugin(element='p')
 ]
 

wagtail/admin/tests/test_widgets.py

@@ -3,6 +3,7 @@ from django.test.utils import override_settings
 
 from wagtail.admin import widgets
 from wagtail.core.models import Page
+from wagtail.tests.testapp.forms import AdminStarDateInput
 from wagtail.tests.testapp.models import EventPage, SimplePage
 
 
@@ -122,6 +123,16 @@ class TestAdminDateInput(TestCase):
             html,
         )
 
+    def test_media_inheritance(self):
+        """
+        Widgets inheriting from AdminDateInput should have their media definitions merged
+        with AdminDateInput's
+        """
+        widget = AdminStarDateInput()
+        media_html = str(widget.media)
+        self.assertIn('wagtailadmin/js/date-time-chooser.js', media_html)
+        self.assertIn('vendor/star_date.js', media_html)
+
 
 class TestAdminDateTimeInput(TestCase):
 

wagtail/admin/widgets.py

@@ -2,6 +2,7 @@ import itertools
 import json
 from functools import total_ordering
 
+from django import forms
 from django.conf import settings
 from django.forms import widgets
 from django.forms.utils import flatatt
@@ -59,8 +60,11 @@ class AdminDateInput(widgets.DateInput):
 
         return context
 
-    class Media:
-        js = [versioned_static('wagtailadmin/js/date-time-chooser.js')]
+    @property
+    def media(self):
+        return forms.Media(js=[
+            versioned_static('wagtailadmin/js/date-time-chooser.js'),
+        ])
 
 
 class AdminTimeInput(widgets.TimeInput):
@@ -72,8 +76,11 @@ class AdminTimeInput(widgets.TimeInput):
             default_attrs.update(attrs)
         super().__init__(attrs=default_attrs, format=format)
 
-    class Media:
-        js = [versioned_static('wagtailadmin/js/date-time-chooser.js')]
+    @property
+    def media(self):
+        return forms.Media(js=[
+            versioned_static('wagtailadmin/js/date-time-chooser.js'),
+        ])
 
 
 class AdminDateTimeInput(widgets.DateTimeInput):
@@ -100,8 +107,11 @@ class AdminDateTimeInput(widgets.DateTimeInput):
 
         return context
 
-    class Media:
-        js = [versioned_static('wagtailadmin/js/date-time-chooser.js')]
+    @property
+    def media(self):
+        return forms.Media(js=[
+            versioned_static('wagtailadmin/js/date-time-chooser.js'),
+        ])
 
 
 class AdminTagWidget(TagWidget):
@@ -238,11 +248,12 @@ class AdminPageChooser(AdminChooser):
             user_perms=json.dumps(self.user_perms),
         )
 
-    class Media:
-        js = [
+    @property
+    def media(self):
+        return forms.Media(js=[
             versioned_static('wagtailadmin/js/page-chooser-modal.js'),
             versioned_static('wagtailadmin/js/page-chooser.js'),
-        ]
+        ])
 
 
 @total_ordering

wagtail/contrib/settings/forms.py

@@ -8,10 +8,11 @@ from wagtail.core.models import Site
 class SiteSwitchForm(forms.Form):
     site = forms.ChoiceField(choices=[])
 
-    class Media:
-        js = [
+    @property
+    def media(self):
+        return forms.Media(js=[
             versioned_static('wagtailsettings/js/site-switcher.js'),
-        ]
+        ])
 
     def __init__(self, current_site, model, **kwargs):
         initial_data = {'site': self.get_change_url(current_site, model)}

wagtail/documents/widgets.py

@@ -1,5 +1,6 @@
 import json
 
+from django import forms
 from django.template.loader import render_to_string
 from django.utils.translation import ugettext_lazy as _
 
@@ -32,8 +33,9 @@ class AdminDocumentChooser(AdminChooser):
     def render_js_init(self, id_, name, value):
         return "createDocumentChooser({0});".format(json.dumps(id_))
 
-    class Media:
-        js = [
+    @property
+    def media(self):
+        return forms.Media(js=[
             versioned_static('wagtaildocs/js/document-chooser-modal.js'),
             versioned_static('wagtaildocs/js/document-chooser.js'),
-        ]
+        ])

wagtail/images/widgets.py

@@ -1,5 +1,6 @@
 import json
 
+from django import forms
 from django.template.loader import render_to_string
 from django.utils.translation import ugettext_lazy as _
 
@@ -32,8 +33,9 @@ class AdminImageChooser(AdminChooser):
     def render_js_init(self, id_, name, value):
         return "createImageChooser({0});".format(json.dumps(id_))
 
-    class Media:
-        js = [
+    @property
+    def media(self):
+        return forms.Media(js=[
             versioned_static('wagtailimages/js/image-chooser-modal.js'),
             versioned_static('wagtailimages/js/image-chooser.js'),
-        ]
+        ])

wagtail/snippets/widgets.py

@@ -1,5 +1,6 @@
 import json
 
+from django import forms
 from django.template.loader import render_to_string
 from django.utils.translation import ugettext_lazy as _
 
@@ -41,8 +42,9 @@ class AdminSnippetChooser(AdminChooser):
                 app=model._meta.app_label,
                 model=model._meta.model_name)))
 
-    class Media:
-        js = [
+    @property
+    def media(self):
+        return forms.Media(js=[
             versioned_static('wagtailsnippets/js/snippet-chooser-modal.js'),
             versioned_static('wagtailsnippets/js/snippet-chooser.js'),
-        ]
+        ])

wagtail/tests/testapp/forms.py

@@ -1,6 +1,7 @@
 from django import forms
 
 from wagtail.admin.forms import WagtailAdminPageForm
+from wagtail.admin.widgets import AdminDateInput
 
 
 class ValidatedPageForm(WagtailAdminPageForm):
@@ -27,3 +28,10 @@ class FormClassAdditionalFieldPageForm(WagtailAdminPageForm):
             raise forms.ValidationError('Code is not valid')
 
         return cleaned_data
+
+
+class AdminStarDateInput(AdminDateInput):
+    # Media definitions defined as `class Media:` should be merged into
+    # the media of the parent class
+    class Media:
+        js = ['vendor/star_date.js']