ionic-framework/js/utils/utils.js

(function(ionic) {
  
  ionic.Utils = {
     // Borrowed from Backbone.js's extend
     // Helper function to correctly set up the prototype chain, for subclasses.
     // Similar to `goog.inherits`, but uses a hash of prototype properties and
     // class properties to be extended.
    inherit: function(protoProps, staticProps) {
      var parent = this;
      var child;

      // The constructor function for the new subclass is either defined by you
      // (the "constructor" property in your `extend` definition), or defaulted
      // by us to simply call the parent's constructor.
      if (protoProps && protoProps.hasOwnProperty('constructor')) {
        child = protoProps.constructor;
      } else {
        child = function(){ return parent.apply(this, arguments); };
      }

      // Add static properties to the constructor function, if supplied.
      ionic.extend(child, parent, staticProps);

      // Set the prototype chain to inherit from `parent`, without calling
      // `parent`'s constructor function.
      var Surrogate = function(){ this.constructor = child; };
      Surrogate.prototype = parent.prototype;
      child.prototype = new Surrogate;

      // Add prototype properties (instance properties) to the subclass,
      // if supplied.
      if (protoProps) ionic.extend(child.prototype, protoProps);

      // Set a convenience property in case the parent's prototype is needed
      // later.
      child.__super__ = parent.prototype;

      return child;
    },

    // Extend adapted from Underscore.js
    extend: function(obj) {
       var args = Array.prototype.slice.call(arguments, 1);
       for(var i = 0; i < args.length; i++) {
         var source = args[i];
         if (source) {
           for (var prop in source) {
             obj[prop] = source[prop];
           }
         }
       }
       return obj;
    }
  };

  ionic.inherit = ionic.Utils.inherit;
  ionic.extend = ionic.Utils.extend;

})(window.ionic);