When I refresh the page, my custom Django CMS plugin's children become invalid

Question

I have written the simplest Django CMS plugin possible that allows children (I use Python 3.4.3, Django 1.7.10, Django CMS 3.1.3):

cms_plugins.py:

from cms.plugin_base import CMSPluginBase
from cms.plugin_pool import plugin_pool

class SamplePlugin(CMSPluginBase):
    allow_children = True
    render_template = "sample_plugin.html"

    def render(self, context, instance, placeholder):
        context['instance'] = instance
        return context

plugin_pool.register_plugin(SamplePlugin)

templates/sample_plugin.html:

{% load cms_tags %}

{% for plugin in instance.child_plugins %}{% render_plugin plugin %}{% endfor %}

I don't use a custom model, just render the child plugins.

I then opened a page in Structure mode and added one instance of that Sampe Plugin and a Style Plugin to a placeholder - so far, so good. I can edit both, of course there is not much to edit for my own plugin. When I now move the Style Plugin into my Sample Plugin, I can still edit the Style Plugin. Switching to content mode and inspecting the DOM, the plugins really are nested.

However, if I now refresh the page, something is clearly inconsistent:

the div corresponding to the Sample Plugin is empty in the DOM
in Structure mode, the nested Style Plugin no longer shows a context menu
double clicking it opens the parent Sample Plugin's editor (the DOM shows the parent's id in the iframe source. Manually changing that URL opens the right Editor)
the Style Plugin can no longer be moved around

A quick inspection of djangocms_style doesn't show any obvious differences that seem relevant to the problem. What's going on here?

I'm also getting stack traces similar to these, but they seem to be unrelated - it happens when adding any plugin - and don't disrupt anything else - no 503 or anything.

score 1 · Accepted Answer · answered Nov 08 '15 at 14:43

The problem seems to be in the template, it's supposed to be

{% for plugin in instance.child_plugin_instances %}

instead if

{% for plugin in instance.child_plugins %}

This seems to have changed between Django CMS 2.4 and 3.0: Compare the information on 2.4 and 3.0 (look at parent.html)

I have found it's not necessary to override render to add context['instance']; the Style Plugin doesn't do that either.

When I refresh the page, my custom Django CMS plugin's children become invalid

1 Answers1