specify a custom widget for StreamFieldPanel (that currently doesn't do very much)

wagtail/wagtailadmin/edit_handlers.py

@@ -619,7 +619,9 @@ Page.settings_panels = [
 
 
 class BaseStreamFieldPanel(BaseFieldPanel):
-    pass
+    @classmethod
+    def widget_overrides(cls):
+        return {cls.field_name: widgets.StreamWidget()}
 
 def StreamFieldPanel(field_name):
     return type(str('_StreamFieldPanel'), (BaseStreamFieldPanel,), {

wagtail/wagtailadmin/views/pages.py

@@ -302,6 +302,7 @@ def edit(request, page_id):
         form.clean = clean
 
         if form.is_valid() and not page.locked:
+            raise Exception(repr(form.cleaned_data))
             page = form.save(commit=False)
 
             is_publishing = bool(request.POST.get('action-publish')) and page_perms.can_publish()

wagtail/wagtailadmin/widgets.py

@@ -5,6 +5,7 @@ import json
 from django.core.urlresolvers import reverse
 from django.forms import widgets
 from django.contrib.contenttypes.models import ContentType
+from django.utils.safestring import mark_safe
 
 from wagtail.utils.widgets import WidgetWithScript
 from wagtail.wagtailcore.models import Page
@@ -53,3 +54,11 @@ class AdminPageChooser(WidgetWithScript, widgets.Input):
                 app=content_type.app_label,
                 model=content_type.model)),
             parent=json.dumps(parent.id if parent else None))
+
+
+class StreamWidget(widgets.Widget):
+    def render(self, name, value, attrs=None):
+        return mark_safe("<strong>hello from StreamWidget</strong>")
+
+    def value_from_datadict(self, data, files, name):
+        return 'lol idk'