Summary
-------

Provide a generic and ergonomic relation widget

How to use it
~~~~~~~~~~~~~

Add the widget in your `uicfg.py` file via uicfg configuration tool.

If you are using `cubicweb.web.uihelper.FormConfig`::

    from cubicweb.web import uihelper
    from cubes.relationwidget.views import RelationFacetWidget

    class MyEntityConfing(uihelper.FormConfig):
          etype = 'MyEntity'
          rels_as_attrs = ('my_relation', )  # edit the relation as attribut
          widgets = dict(
              my_relation=RelationFacetWidget, # use the RelationFacetWidget for `my_relation`
          )

You can also use it directely via `uicfg.autoform_field_kwarg`::

    from cubicweb.web.views import uicfg
    from cubes.relationwidget.views import RelationFacetWidget

    # edit the relation as attribute.
    uicfg.autoform_section.tag_subject_of(('MyEntity', 'my_relation', '*'),
                                           formtype=('main', 'muledit'),
                                           section='attributes')

    # add the RelationFacetWidget for `my_relation`
    uicfg.autoform_field_kwargs.tag_subject_of(('MyEntity', 'my_relation', '*'),
                                               {'widget': RelationFacetWidget})

