text: /** @license MIT License (c) copyright B Cavalier & J Hann */
  
  /**
   * cancelable.js
   *
   * Decorator that makes a deferred "cancelable".  It adds a cancel() method that
   * will call a special cancel handler function and then reject the deferred.  The
   * cancel handler can be used to do resource cleanup, or anything else that should
   * be done before any other rejection handlers are executed.
   *
   * Usage:
   *
   * var cancelableDeferred = cancelable(when.defer(), myCancelHandler);
   *
   * @author brian@hovercraftstudios.com
   */
  
  (function(define) {
  define(function(require) {
  
  	var when = require('./when');
  
      /**
       * Makes deferred cancelable, adding a cancel() method.
       *
       * @param deferred {Deferred} the {@link Deferred} to make cancelable
       * @param canceler {Function} cancel handler function to execute when this deferred
  	 * is canceled.  This is guaranteed to run before all other rejection handlers.
  	 * The canceler will NOT be executed if the deferred is rejected in the standard
  	 * way, i.e. deferred.reject().  It ONLY executes if the deferred is canceled,
  	 * i.e. deferred.cancel()
       *
       * @returns deferred, with an added cancel() method.
       */
      return function(deferred, canceler) {
  
          var delegate = when.defer();
  
          // Add a cancel method to the deferred to reject the delegate
          // with the special canceled indicator.
          deferred.cancel = function() {
              return deferred.reject(canceler(deferred));
          };
  
          // Ensure that the original resolve, reject, and progress all forward
          // to the delegate
          deferred.promise.then(delegate.resolve, delegate.reject, delegate.notify);
  
          // Replace deferred's promise with the delegate promise
          deferred.promise = delegate.promise;
  
          // Also replace deferred.then to allow it to be called safely and
          // observe the cancellation
  		// TODO: Remove once deferred.then is removed
          deferred.then = delegate.promise.then;
  
          return deferred;
      };
  
  });
  })(
  	typeof define === 'function' && define.amd ? define : function (factory) { module.exports = factory(require); }
  	// Boilerplate for AMD and Node
  );
  
  
  