Adds an invert method to promises that returns a "inverted" promise that is resolved...

[jquery.git] / src / core.js

diff --git a/src/core.js b/src/core.js
index faf205c..915ac6b 100644 (file)
--- a/src/core.js
+++ b/src/core.js
@@ -56,8 +56,16 @@ var jQuery = function( selector, context ) {
        // The deferred used on DOM ready
        readyList,
 
-       // Promise methods
-       promiseMethods = "then done fail isResolved isRejected promise".split( " " ),
+       // Promise methods (with equivalent for invert)
+       promiseMethods = {
+               then: 0, // will be overwritten for invert
+               done: "fail",
+               fail: "done",
+               isResolved: "isRejected",
+               isRejected: "isResolved",
+               promise: "invert",
+               invert: "promise"
+       },
 
        // The ready event handler
        DOMContentLoaded,
@@ -879,8 +887,9 @@ jQuery.extend({
        Deferred: function( func ) {
                var deferred = jQuery._Deferred(),
                        failDeferred = jQuery._Deferred(),
-                       promise;
-               // Add errorDeferred methods, then and promise
+                       promise,
+                       invert;
+               // Add errorDeferred methods, then, promise and invert
                jQuery.extend( deferred, {
                        then: function( doneCallbacks, failCallbacks ) {
                                deferred.done( doneCallbacks ).fail( failCallbacks );
@@ -892,17 +901,34 @@ jQuery.extend({
                        isRejected: failDeferred.isResolved,
                        // Get a promise for this deferred
                        // If obj is provided, the promise aspect is added to the object
-                       promise: function( obj , i /* internal */ ) {
+                       promise: function( obj ) {
                                if ( obj == null ) {
                                        if ( promise ) {
                                                return promise;
                                        }
                                        promise = obj = {};
                                }
-                               i = promiseMethods.length;
-                               while( i-- ) {
-                                       obj[ promiseMethods[ i ] ] = deferred[ promiseMethods[ i ] ];
+                               for( var methodName in promiseMethods ) {
+                                       obj[ methodName ] = deferred[ methodName ];
+                               }
+                               return obj;
+                       },
+                       // Get the invert promise for this deferred
+                       // If obj is provided, the invert promise aspect is added to the object
+                       invert: function( obj ) {
+                               if ( obj == null ) {
+                                       if ( invert ) {
+                                               return invert;
+                                       }
+                                       invert = obj = {};
+                               }
+                               for( var methodName in promiseMethods ) {
+                                       obj[ methodName ] = promiseMethods[ methodName ] && deferred[ promiseMethods[methodName] ];
                                }
+                               obj.then = invert.then || function( doneCallbacks, failCallbacks ) {
+                                       deferred.done( failCallbacks ).fail( doneCallbacks );
+                                       return this;
+                               };
                                return obj;
                        }
                } );