Remembering I'm a real n00b please.
I am editing a copy of an existing plugin - Category List (as a model for my own - easier to start with something that is known to work)
To _coll_category_list.widget.php I have added a new disp param to function get_param_definitions(). This was simple and it works fine. I can edit it in Dashboard making a setting which then is recognised by $this->disp_params[''] in the function display().
I can also change the new parameter in the calling method of index.main.php of the appropriate skin. ie
'block_start' => '',
'block_end' => '',
'block_display_title' => false,
'new_param' => 'alpha',
'list_start' => '',
'list_end' => ''',
'item_start' => ''',
'item_selected_start' => '',
'item_end' => '',
'use_form' => true,
Everything OK so far.
That param 'use_form' does not seem to take a value of true. So when tested in the _coll_category_list.widget.php it does nothing !
I could probably create a new param and use that as an alternate in the test but this seems clumsy when a param is already supplied.
Or am I missing something ?