Rich text field on a property sheet in a control panel

controlpanel.py

from z3c.form import form
from z3c.form import field
from plone.app.registry.browser.controlpanel import ControlPanelFormWrapper
from plone.app.textfield.value import RichTextValue
from plone.z3cform import layout
from Products.CMFCore.utils import getToolByName


class IMyFormSchema(Interface):
    text = RichText(title=u"Text", required=False, default=u"")


class MyFormPropertySheetAdapter(object):
    def __init__(self, context):
        self.context = context

    text = RichTextProxy(IMyFormSchema['text'])


class MyForm(form.EditForm):
    fields = field.Fields(IMyFormSchema)

    def getContent(self):
        props = getToolByName(self.context, 'portal_properties')
        sheet = props['my_properties']
        return MyFormPropertySheetAdapter(sheet)


MyControlPanel = layout.wrap_form(MyForm, ControlPanelFormWrapper)


class RichTextProxy(object):
    def __init__(self, context):
        self.context = context

    def __get__(self, inst, cls=None):
        if inst is None:
            return self

        d = {}
        for name, string in inst.context.propertyItems():
            s = self.context.__name__ + "_"
            if name.startswith(s):
                key = name[len(s):]
                d[key] = string

        if d:
            return RichTextValue(**d)

        return self.context.default

    def __set__(self, inst, value):
        field = self.context.bind(inst)
        field.validate(value)

        for key in ('raw', 'mimeType', 'outputMimeType', 'encoding'):
            name = field.__name__ + "_" + key
            string = getattr(value, key)
            if not hasattr(inst.context, name):
                inst.context.manage_addProperty(name, string, 'string')
            else:
                inst.context._updateProperty(name, string)