JEM in Joomla 3 with joomla's custom fields

[jojo12]

Hi, I tried to implement joomla's custom fields into JEM. And I succeeded in some (first) way. :-)

1. For the backend I inserted in /helpers/helper.php in addSubmenu:
   ` if (JComponentHelper::isEnabled('com_fields') && JComponentHelper::getParams('com_jem')->get('custom_fields_enable', '1'))
   {
   JHtmlSidebar::addEntry(
   JText::_('JGLOBAL_FIELDS'),
   'index.php?option=com_fields&context=com_jem.event',
   $vName == 'fields.fields'
   );

   	JHtmlSidebar::addEntry(
   		JText::_('JGLOBAL_FIELD_GROUPS'),
   		'index.php?option=com_fields&view=groups&context=com_jem.event',
   		$vName == 'fields.groups'
   	);
   }`
   

2. Then I added in access.xml the code you find here
   and in the
   <section name="component"> <action name="core.edit.value" title="JACTION_EDITVALUE" description="JACTION_EDITVALUE_COMPONENT_DESC" />

3. in the config.xml I added:
   ` <fieldset
   name="integration"
   label="JGLOBAL_INTEGRATION_LABEL"
   description="COM_JEM_CONFIG_INTEGRATION_SETTINGS_DESC"

    <field
    	name="custom_fields_enable"
    	type="radio"
    	label="JGLOBAL_CUSTOM_FIELDS_ENABLE_LABEL"
    	description="JGLOBAL_CUSTOM_FIELDS_ENABLE_DESC"
    	default="0"
    	class="btn-group btn-group-yesno"
    >
    	<option value="1">JYES</option>
    	<option value="0">JNO</option>
    </field>
   

   `

With that I can enable/disable integration of joomla custom fields in JEM (in Options)
In backend I see now in the submenu "Fields" and "Fieldgroups".

I created a new field and saved. Then I created a new event. Under the Description field there's a button "Fields". Clicking on it I can choose a (this) custom field in a modal window.
When I look in Frontend, I see in the description content the content of my created custom field.

I tried with text, calendar. Will try with more.

[jojo12]

It only works in event. I see the view.html.php of event has onContentPrepare.
When I look into view.html.php of venue there's no onContentPrepare.

[jojo12]

My question:
If I proceed like described, I get a field-button to insert a field in the description,
But "how to do" for the field tab above the description in the editevent-view?