1.js

  alight.filters.throttle = {
    init: function(delay, scope) {
      this.delay = Number(delay);
      this.to = null;
      this.scope = scope;
    },
    onChange: function(value) {
      var that;
      that = this;
      if (this.to) {
        clearTimeout(this.to);
      }
      this.to = setTimeout(function() {
        that.to = null;
        that.setValue(value);
        that.scope.$scan();
      }, this.delay);
    }
  };

2.js

  alight.filters.throttle = {
    init: function(delay, scope, env) {
      delay = Number(delay);
      var to = null;
    
      return {
        onChange: function(value) {
          if(to) {
            clearTimeout(to);
          }
          to = setTimeout(function() {
            to = null;
            env.setValue(value);
            scope.$scan();
          }, delay);
        }
      } // return
      
    }
  };