third_party/polymer/v1_0/components-chromium/more-routing/params-extracted.js

   1
   2 (function(scope) {
   3 var MoreRouting = scope.MoreRouting = scope.MoreRouting || {};
   4 MoreRouting.Params = Params;
   5
   6 /**
   7  * A collection of route parameters and their values, with nofications.
   8  *
   9  * Params prefixed by `__` are reserved.
  10  *
  11  * @param {!Array<string>} params The keys of the params being managed.
  12  * @param {Params=} parent A parent route's params to inherit.
  13  * @return {Params}
  14  */
  15 function Params(params, parent) {
  16   var model = Object.create(parent || Params.prototype);
  17   // We have a different set of listeners at every level of the hierarchy.
  18   Object.defineProperty(model, '__listeners', {value: []});
  19
  20   // We keep all state enclosed within this closure so that inheritance stays
  21   // relatively straightfoward.
  22   var state = {};
  23   _compile(model, params, state);
  24
  25   return model;
  26 }
  27 Params.prototype = Object.create(MoreRouting.Emitter);
  28
  29 // Utility
  30
  31 function _compile(model, params, state) {
  32   params.forEach(function(param) {
  33     Object.defineProperty(model, param, {
  34       get: function() {
  35         return state[param];
  36       },
  37       set: function(value) {
  38         if (state[param] === value) return;
  39         state[param] = value;
  40         model.__notify(param, value);
  41       },
  42     });
  43   });
  44 }
  45
  46 })(window);