Introduce a way to group code into classes.

We can choose a simpler implementation in the near future.

1 files changed, 64 insertions, 0 deletions

diff --git a/lib/utils.js b/lib/utils.js
index 7ed7c9ad..ca7ce2bc 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -159,3 +159,67 @@ var utils = {
   },
 
 };
+
+/*
+ * Simple JavaScript Inheritance, by John Resig.
+ * This provides a short syntax for organizing code into classes.
+ * Taken from http://ejohn.org/blog/simple-javascript-inheritance/.
+ */
+(function(){
+  var initializing = false, fnTest = /xyz/.test(function(){xyz;}) ? /\b_super\b/ : /.*/;
+  // The base Class implementation (does nothing)
+  this.Class = function(){};
+
+  // Create a new Class that inherits from this class
+  Class.extend = function(prop) {
+    var _super = this.prototype;
+
+    // Instantiate a base class (but only create the instance,
+    // don't run the init constructor)
+    initializing = true;
+    var prototype = new this();
+    initializing = false;
+
+    // Copy the properties over onto the new prototype
+    for (var name in prop) {
+      // Check if we're overwriting an existing function
+      prototype[name] = typeof prop[name] == "function" &&
+        typeof _super[name] == "function" && fnTest.test(prop[name]) ?
+        (function(name, fn){
+          return function() {
+            var tmp = this._super;
+
+            // Add a new ._super() method that is the same method
+            // but on the super-class
+            this._super = _super[name];
+
+            // The method only need to be bound temporarily, so we
+            // remove it when we're done executing
+            var ret = fn.apply(this, arguments);
+            this._super = tmp;
+
+            return ret;
+          };
+        })(name, prop[name]) :
+        prop[name];
+    }
+
+    // The dummy class constructor
+    function Class() {
+      // All construction is actually done in the init method
+      if ( !initializing && this.init )
+        this.init.apply(this, arguments);
+    }
+
+    // Populate our constructed prototype object
+    Class.prototype = prototype;
+
+    // Enforce the constructor to be what we expect
+    Class.prototype.constructor = Class;
+
+    // And make this class extendable
+    Class.extend = arguments.callee;
+
+    return Class;
+  };
+})();