misc: give widget templates full access to publisher context (#24338)

tests/templates/qommon/forms/widgets/select--test.html

@@ -2,6 +2,7 @@
 {% block widget-control %}
 <!-- TEST TEMPLATE -->
 <!-- backoffice: {{ request.quixote_request.is_in_backoffice|pprint }} -->
+<!-- substitution variable: {{ example_url }} -->
 <select id="form_{{widget.name}}" name="{{widget.name}}"
     {% for attr in widget.attrs.items %}{{attr.0}}="{{attr.1}}"{% endfor %}>
   <option value="">---</option>

tests/test_form_pages.py

@@ -4547,6 +4547,15 @@ def test_form_custom_select_template(pub):
     # make sure request is available in context
     assert '<!-- backoffice: False -->' in resp.body
 
+    # test for substitution variables being available
+    if not pub.site_options.has_section('variables'):
+        pub.site_options.add_section('variables')
+    pub.site_options.set('variables', 'example_url', 'http://remote.example.net/')
+    with open(os.path.join(pub.app_dir, 'site-options.cfg'), 'w') as fd:
+        pub.site_options.write(fd)
+    resp = get_app(pub).get('/test/')
+    assert 'substitution variable: http://remote.example.net/' in resp.body
+
 def test_form_status_appearance_keywords(pub):
     create_user(pub)
     formdef = create_formdef()

wcs/qommon/form.py

@@ -128,7 +128,11 @@ def render(self):
     self.rendered_title = lambda: safe(self.render_title(self.get_title()))
     self.rendered_error = lambda: safe(self.render_error(self.get_error()))
     self.rendered_hint = lambda: safe(self.render_hint(self.get_hint()))
-    context = {'widget': self}
+    if get_publisher():
+        context = get_publisher().substitutions.get_context_variables()
+    else:
+        context = {}
+    context['widget'] = self
     template_names = get_template_names(self)
     return htmltext(render_template(template_names, context))