ker/cls/WTag.js
function(vars, slot, getter) {
            if (!Array.isArray(vars)) {
                vars = [vars];
            }
            if (vars.length == 0) return null;
            if (typeof slot === 'string') {
                slot = this[slot];
            }
            if (typeof getter === 'undefined') {
                getter = function() {
                    return this.data(vars[0]);
                };
            }
            var listener = {
                obj: this,
                slot: slot,
                getter: getter
            };
            vars.forEach(
                function(name) {
                    var data = this.findDataBinding(name);
                    data[1].push(listener);
                }, this
            );
            return listener;
        }
function(vars, slot, getter) {
            if (!Array.isArray(vars)) {
                vars = [vars];
            }
            if (vars.length == 0) return null;
            if (typeof slot === 'string') {
                slot = this[slot];
            }
            if (typeof getter === 'undefined') {
                getter = function() {
                    return this.data(vars[0]);
                };
            }
            var listener = {
                obj: this,
                slot: slot,
                getter: getter
            };
            vars.forEach(
                function(name) {
                    var data = this.findDataBinding(name);
                    data[1].push(listener);
                }, this
            );
            return listener;
        }
function ( vars , slot , getter ) { if ( ! Array . isArray ( vars ) ) { vars = [ vars ] ; } if ( vars . length == 0 ) return null ; if ( typeof slot === 'string' ) { slot = this [ slot ] ; } if ( typeof getter === 'undefined' ) { getter = function ( ) { return this . data ( vars [ 0 ] ) ; } ; } var listener = { obj : this , slot : slot , getter : getter } ; vars . forEach ( function ( name ) { var data = this . findDataBinding ( name ) ; data [ 1 ] . push ( listener ) ; } , this ) ; return listener ; }
Bind to data updates.
When the data changed, the  `slot` is call with `this` object
and the data's value as unique argument.
@param {array} vars array of names of data to watch.
@param {function} slot function to call when data changed.
@param {string} slot name of the method to call when data changed.
@param {function} getter function getting the binded value.
@return {object} the listener you can give to `unbindData`.
@memberof WTag
Bind to data updates . When the data changed the slot is call with this object and the data s value as unique argument .