Update SummaryItem to use components

wagtail/admin/site_summary.py

@@ -1,22 +1,70 @@
-from django.template.loader import render_to_string
+from warnings import warn
+
+from django.template.loader import get_template, render_to_string
 
 from wagtail.admin.auth import user_has_any_page_permission
 from wagtail.admin.navigation import get_site_for_user
+from wagtail.admin.ui.components import Component
 from wagtail.core import hooks
 from wagtail.core.models import Page, Site
+from wagtail.utils.deprecation import RemovedInWagtail217Warning
 
 
-class SummaryItem:
+class SummaryItem(Component):
     order = 100
+    template = None  # RemovedInWagtail217Warning - should set template_name instead
 
     def __init__(self, request):
         self.request = request
 
     def get_context(self):
+        # RemovedInWagtail217Warning:
+        # old get_context method deprecated in 2.15; provided here in case subclasses call it from
+        # overridden render() methods or via super()
         return {}
+    get_context.is_base_method = True
 
     def render(self):
+        # RemovedInWagtail217Warning:
+        # old render method deprecated in 2.15; provided here in case subclasses call it via super()
         return render_to_string(self.template, self.get_context(), request=self.request)
+    render.is_base_method = True
+
+    def render_html(self, parent_context=None):
+        if not getattr(self.render, 'is_base_method', False):
+            # this SummaryItem subclass has overridden render() - use their implementation in
+            # preference to following the Component.render_html path
+            message = (
+                "Summary item %r registered with construct_homepage_summary_items must be updated "
+                "to override render_html(self, parent_context) rather than render(self)"
+                % self
+            )
+            warn(message, category=RemovedInWagtail217Warning)
+            return self.render()
+        elif not getattr(self.get_context, 'is_base_method', False):
+            # this SummaryItem subclass has overridden get_context() - use their implementation in
+            # preference to Component.get_context_data
+            message = (
+                "Summary item %r registered with construct_homepage_summary_items must be updated "
+                "to override get_context_data(self, parent_context) rather than get_context(self)"
+                % self
+            )
+            warn(message, category=RemovedInWagtail217Warning)
+            context_data = self.get_context()
+        else:
+            context_data = self.get_context_data(parent_context)
+
+        if self.template is not None:
+            warn(
+                "%s should define template_name instead of template" % type(self).__name__,
+                category=RemovedInWagtail217Warning
+            )
+            template_name = self.template
+        else:
+            template_name = self.template_name
+
+        template = get_template(template_name)
+        return template.render(context_data)
 
     def is_shown(self):
         return True

wagtail/admin/templates/wagtailadmin/home/site_summary.html

@@ -3,7 +3,7 @@
     <h2 class="visuallyhidden">{% trans "Site summary" %}</h2>
     <ul class="stats">
         {% for item in summary_items %}
-            {{ item.render }}
+            {% component item %}
         {% endfor %}
     </ul>
 </section>