nl_tokens: The functional reactive when operator . * properties An array of property names ( can also be a single property string ) . * callback A callback function that is called : * with property values as arguments ordered corresponding to the properties array * only if all specified properties have values * once for initialization * whenever one or more specified properties change * on the next tick of the JavaScript event loop after properties change * only once as a result of one or more synchronous changes to dependency properties .
pl_tokens: function when ( properties , callback ) { // This function will trigger the callback to be invoked. var triggerCallback = debounce ( function ( ) { var args = <mask> . map ( function ( property ) { return values [ property ] ; } ) ; if ( allAreDefined ( args ) ) { callback . apply ( null , args ) ; } } ) ; // Handle either an array or a single string. properties = ( properties instanceof Array ) ? properties : [ properties ] ; // Trigger the callback once for initialization. triggerCallback ( ) ; // Trigger the callback whenever specified properties change. properties . forEach ( function ( property ) { on ( property , triggerCallback ) ; } ) ; }