Use alternate context var for Jinja support

Jinja does not support using `self` as a template variable, as `self` is
reserved for its own internal use. To add support for Jinja templates,
an alternative name has been added where 'self' has been used.  Template
authors are free to use which ever template variable works in their
template language.

wagtail/wagtailadmin/edit_handlers.py

@@ -421,6 +421,8 @@ class MultiFieldPanel(object):
 
 class BaseFieldPanel(EditHandler):
 
+    TEMPLATE_VAR = 'field_panel'
+
     @classmethod
     def widget_overrides(cls):
         """check if a specific widget has been defined for this field"""
@@ -459,6 +461,7 @@ class BaseFieldPanel(EditHandler):
     def render_as_object(self):
         return mark_safe(render_to_string(self.object_template, {
             'self': self,
+            self.TEMPLATE_VAR: self,
             'field': self.bound_field,
         }))
 

wagtail/wagtailadmin/templates/wagtailadmin/userbar/frame.html

@@ -4,7 +4,7 @@
     var wagtail = wagtail || {};
     wagtail.static_root = '{% static "wagtailadmin/" %}';
     wagtail.userbar = {
-        src: '{% if revision_id %}{% url "wagtailadmin_userbar_moderation" revision_id %}{% else %}{% url "wagtailadmin_userbar_frontend" page.self.id %}{% endif %}',
+        src: '{% if revision_id %}{% url "wagtailadmin_userbar_moderation" revision_id %}{% else %}{% url "wagtailadmin_userbar_frontend" page.id %}{% endif %}',
         origin:'{% if request.is_secure %}https{% else %}http{% endif %}://{{ request.get_host }}'
     };
     (function(d) {
@@ -13,4 +13,4 @@
         var s = d.getElementsByTagName('script')[0]; s.parentNode.insertBefore(u, s);
     })(document);
 </script>
-<!-- end Wagtail user bar embed code -->
+<!-- end Wagtail user bar embed code -->

wagtail/wagtailadmin/templatetags/wagtailuserbar.py

@@ -1,7 +1,7 @@
 from django import template
 from django.template.loader import render_to_string
 
-from wagtail.wagtailcore.models import Page
+from wagtail.wagtailcore.models import Page, PAGE_TEMPLATE_VAR
 
 
 register = template.Library()
@@ -16,10 +16,13 @@ def wagtailuserbar(context):
     if not request.user.has_perm('wagtailadmin.access_admin'):
         return ''
 
-    # Only render if the context contains a 'self' variable referencing a saved page
-    if 'self' in context and isinstance(context['self'], Page) and context['self'].id is not None:
-        pass
-    else:
+    # Only render if the context contains a 'PAGE_TEMPLATE_VAR' variable
+    # referencing a saved page
+    if PAGE_TEMPLATE_VAR not in context:
+        return ''
+
+    page = context[PAGE_TEMPLATE_VAR]
+    if not isinstance(page, Page) or page.id is None:
         return ''
 
     try:
@@ -30,6 +33,6 @@ def wagtailuserbar(context):
     # Render the frame to contain the userbar items
     return render_to_string('wagtailadmin/userbar/frame.html', {
         'request': request,
-        'page': context,
+        'page': page,
         'revision_id': revision_id
     })

wagtail/wagtailadmin/tests/test_userbar.py

@@ -6,7 +6,7 @@ from django.contrib.auth import get_user_model
 from django.contrib.auth.models import AnonymousUser
 
 from wagtail.tests.utils import WagtailTestUtils
-from wagtail.wagtailcore.models import Page
+from wagtail.wagtailcore.models import Page, PAGE_TEMPLATE_VAR
 from wagtail.tests.testapp.models import BusinessIndex, BusinessChild
 
 
@@ -23,7 +23,7 @@ class TestUserbarTag(TestCase):
     def test_userbar_tag(self):
         template = Template("{% load wagtailuserbar %}{% wagtailuserbar %}")
         content = template.render(Context({
-            'self': self.homepage,
+            PAGE_TEMPLATE_VAR: self.homepage,
             'request': self.dummy_request(self.user),
         }))
 
@@ -32,7 +32,7 @@ class TestUserbarTag(TestCase):
     def test_userbar_tag_anonymous_user(self):
         template = Template("{% load wagtailuserbar %}{% wagtailuserbar %}")
         content = template.render(Context({
-            'self': self.homepage,
+            PAGE_TEMPLATE_VAR: self.homepage,
             'request': self.dummy_request(),
         }))
 

wagtail/wagtailcore/blocks/base.py

@@ -41,6 +41,8 @@ class Block(six.with_metaclass(BaseBlock, object)):
     name = ''
     creation_counter = 0
 
+    TEMPLATE_VAR = 'value'
+
     class Meta:
         label = None
         icon = "placeholder"
@@ -206,7 +208,10 @@ class Block(six.with_metaclass(BaseBlock, object)):
         """
         template = getattr(self.meta, 'template', None)
         if template:
-            return render_to_string(template, {'self': value})
+            return render_to_string(template, {
+                'self': value,
+                self.TEMPLATE_VAR: value,
+            })
         else:
             return self.render_basic(value)
 

wagtail/wagtailcore/models.py

@@ -44,6 +44,8 @@ from wagtail.wagtailsearch.backends import get_search_backend
 
 logger = logging.getLogger('wagtail.core')
 
+PAGE_TEMPLATE_VAR = 'page'
+
 
 class SiteManager(models.Manager):
     def get_by_natural_key(self, hostname, port):
@@ -549,6 +551,7 @@ class Page(six.with_metaclass(PageBase, MP_Node, ClusterableModel, index.Indexed
 
     def get_context(self, request, *args, **kwargs):
         return {
+            PAGE_TEMPLATE_VAR: self,
             'self': self,
             'request': request,
         }