How can I add and remove objects in a relationship N: M.
For example, the following model: Music and listeners.
A song may have been heard by one or more persons,
well as a person may have heard one or more songs.
Considering that is a page displaying information of a song and want to put a button to add the music to the user list.
How to model the action of this flow?
A solution that was used to get the list of IDs of the songs already in relationship and groovy code via add the desired item.
And with the new list of IDs, set up a playlist on user relationship and the music. It worked, but it was not an interesting solution.
There is a way to do this at the level of abstraction of the model using both webratio to insert as to remove objects from a relationship?