nl_tokens: / * register for a callback before an action op : create | read | update | delete | * type : <explicit type > | * listener signature is : function ( intent done ) listener function must call done () to continue or done ( err ) to abort the action note : if more than one listener is registered for an action listeners will be called asynchronously and the first error ( if any ) will be binding so there is no guarantee any particular listener will be called }
pl_tokens: function before ( op , type , listener ) { if ( ! _ . isFunction ( listener ) ) { throw <mask> Error ( 'Callback must be a function' ) ; } if ( ! registeredListeners [ op ] [ type ] ) { registeredListeners [ op ] [ type ] = [ ] ; } registeredListeners [ op ] [ type ] . push ( listener ) ; }