Added deferred to core. Used internally for DOM readyness and ajax callbacks.

src/core.js

@@ -60,8 +60,8 @@ var jQuery = function( selector, context ) {
 	// Has the ready events already been bound?
 	readyBound = false,
 	
-	// The functions to execute on DOM ready
+	// The deferred used on DOM ready
-	readyList = [],
+	readyList,
 
 	// The ready event handler
 	DOMContentLoaded,
@@ -75,7 +75,10 @@ var jQuery = function( selector, context ) {
 	indexOf = Array.prototype.indexOf,
 	
 	// [[Class]] -> type pairs
-	class2type = {};
+	class2type = {},
+	
+	// Marker for deferred
+	deferredMarker = [];
 
 jQuery.fn = jQuery.prototype = {
 	init: function( selector, context ) {
@@ -253,22 +256,12 @@ jQuery.fn = jQuery.prototype = {
 		return jQuery.each( this, callback, args );
 	},
 	
-	ready: function( fn ) {
+	ready: function() {
 		// Attach the listeners
 		jQuery.bindReady();
-
+		
-		// If the DOM is already ready
+		// Change ready & apply
-		if ( jQuery.isReady ) {
+		return ( jQuery.fn.ready = readyList.then ).apply( this , arguments );
-			// Execute the function immediately
-			fn.call( document, jQuery );
-
-		// Otherwise, remember the function for later
-		} else if ( readyList ) {
-			// Add the function to the wait list
-			readyList.push( fn );
-		}
-
-		return this;
 	},
 	
 	eq: function( i ) {
@@ -415,23 +408,11 @@ jQuery.extend({
 			}
 
 			// If there are functions bound, to execute
-			if ( readyList ) {
+			readyList.fire( document , [ jQuery ] );
-				// Execute all of them
+			
-				var fn,
+			// Trigger any bound ready events
-					i = 0,
+			if ( jQuery.fn.trigger ) {
-					ready = readyList;
+				jQuery( document ).trigger( "ready" ).unbind( "ready" );
-
-				// Reset the list of functions
-				readyList = null;
-
-				while ( (fn = ready[ i++ ]) ) {
-					fn.call( document, jQuery );
-				}
-
-				// Trigger any bound ready events
-				if ( jQuery.fn.trigger ) {
-					jQuery( document ).trigger( "ready" ).unbind( "ready" );
-				}
 			}
 		}
 	},
@@ -800,6 +781,160 @@ jQuery.extend({
 	now: function() {
 		return (new Date()).getTime();
 	},
+	
+	// Create a simple deferred (one callbacks list)
+	_deferred: function( cancellable ) {
+		
+		// cancellable by default
+		cancellable = cancellable !== false;
+		
+		var // callbacks list
+			callbacks = [],
+			// stored [ context , args ]
+			fired,
+			// to avoid firing when already doing so
+			firing,
+			// flag to know if the deferred has been cancelled
+			cancelled,
+			// the deferred itself
+			deferred  = {
+				
+				// then( f1, f2, ...)
+				then: function() {
+					
+					if ( ! cancelled ) {
+					
+						var args = arguments,
+							i,
+							type,
+							_fired;
+							
+						if ( fired ) {
+							_fired = fired;
+							fired = 0;
+						}
+						
+						for ( i in args ) {
+							i = args[ i ];
+							type = jQuery.type( i );
+							if ( type === "array" ) {
+								this.then.apply( this , i );
+							} else if ( type === "function" ) {
+								callbacks.push( i );
+							}
+						}
+						
+						if ( _fired ) {
+							deferred.fire( _fired[ 0 ] , _fired[ 1 ] );
+						}
+					}
+					return this;
+				},
+				
+				// resolve with given context and args
+				// (i is used internally)
+				fire: function( context , args , i ) {
+					if ( ! cancelled && ! fired && ! firing ) {
+						firing = 1;
+						try {
+							for( i = 0 ; ! cancelled && callbacks[ i ] ; i++ ) {
+								cancelled = ( callbacks[ i ].apply( context , args ) === false ) && cancellable;
+							}
+						} catch( e ) {
+							cancelled = cancellable;
+							jQuery.error( e );
+						} finally {
+							fired = [ context , args ];
+							callbacks = cancelled ? [] : callbacks.slice( i + 1 );
+							firing = 0;
+						}
+					}
+					return this;
+				},
+				
+				// resolve with this as context and given arguments
+				resolve: function() {
+					deferred.fire( this , arguments );
+					return this;
+				},
+				
+				// cancelling further callbacks
+				cancel: function() {
+					if ( cancellable ) {
+						callbacks = [];
+						cancelled = 1;
+					}
+					return this;
+				}
+				
+			};
+		
+		// Add the deferred marker
+		deferred.then._ = deferredMarker;
+		
+		return deferred;
+	},
+	
+	// Full fledged deferred (two callbacks list)
+	// Typical success/error system
+	deferred: function( func , cancellable ) {
+		
+		// Handle varargs
+		if ( arguments.length === 1 ) {
+			
+			if ( typeof func === "boolean" ) {
+				cancellable = func;
+				func = 0;
+			}
+		}
+		
+		var errorDeferred = jQuery._deferred( cancellable ),
+			deferred = jQuery._deferred( cancellable ),
+			// Keep reference of the cancel method since we'll redefine it
+			cancelThen = deferred.cancel;
+			
+		// Add errorDeferred methods and redefine cancel			
+		jQuery.extend( deferred , {
+
+				fail: errorDeferred.then,
+				fireReject: errorDeferred.fire,
+				reject: errorDeferred.resolve,
+				cancel: function() {
+					cancelThen();
+					errorDeferred.cancel();
+					return this;
+				}
+
+		} );
+		
+		// Make sure only one callback list will be used
+		deferred.then( errorDeferred.cancel ).fail( cancelThen );
+		
+		// Call given func if any
+		if ( func ) {
+			func.call( deferred , deferred );
+		}
+		
+		return deferred;
+	},
+
+	// Check if an object is a deferred
+	isDeferred: function( object , method ) {
+		method = method || "then";
+		return !!( object && object[ method ] && object[ method ]._ === deferredMarker );
+	},
+	
+	// Deferred helper
+	when: function( object , method ) {
+		method = method || "then";
+		object = jQuery.isDeferred( object , method ) ?
+			object :
+			jQuery.deferred().resolve( object );
+		object.fail = object.fail || function() { return this; };
+		object[ method ] = object[ method ] || object.then;
+		object.then = object.then || object[ method ];
+		return object;
+	},
 
 	// Use of jQuery.browser is frowned upon.
 	// More details: http://docs.jquery.com/Utilities/jQuery.browser
@@ -818,6 +953,11 @@ jQuery.extend({
 	browser: {}
 });
 
+// Create readyList deferred
+// also force $.fn.ready to be recognized as a defer
+readyList = jQuery._deferred( false );
+jQuery.fn.ready._ = deferredMarker;
+
 // Populate the class2type map
 jQuery.each("Boolean Number String Function Array Date RegExp Object".split(" "), function(i, name) {
 	class2type[ "[object " + name + "]" ] = name.toLowerCase();

src/xhr.js

@@ -18,18 +18,19 @@ jQuery.xhr = function( _native ) {
 		return jQuery.ajaxSettings.xhr();
 	}
 	
-	function reset(force) {
+	function reset( force ) {
 		
 		// We only need to reset if we went through the init phase
 		// (with the exception of object creation)
 		if ( force || internal ) {
-		
+			
 			// Reset callbacks lists
-			callbacksLists = {
+			deferred = jQuery.deferred();
-				success: createCBList(),
+			completeDeferred = jQuery._deferred();
-				error: createCBList(),
+			
-				complete: createCBList()
+			xhr.success = xhr.then = deferred.then;
-			};
+			xhr.error = xhr.fail = deferred.fail;
+			xhr.complete = completeDeferred.then;
 			
 			// Reset private variables
 			requestHeaders = {};
@@ -155,8 +156,8 @@ jQuery.xhr = function( _native ) {
 		callbackContext = s.context || s;
 		globalEventContext = s.context ? jQuery(s.context) : jQuery.event;
 		
-		for ( i in callbacksLists ) {
+		for ( i in { success:1, error:1, complete:1 } ) {
-			callbacksLists[i].bind(s[i]);
+			xhr[ i ]( s[ i ] );
 		}
 		
 		// Watch for a new set of requests
@@ -355,10 +356,12 @@ jQuery.xhr = function( _native ) {
 		
 		// Keep local copies of vars in case callbacks re-use the xhr
 		var _s = s,
-			_callbacksLists = callbacksLists,
+			_deferred = deferred,
+			_completeDeferred = completeDeferred,
 			_callbackContext = callbackContext,
 			_globalEventContext = globalEventContext;
 			
+			
 		// Set state if the xhr hasn't been re-used
 		function _setState( value ) {
 			if ( xhr.readyState && s === _s ) {
@@ -375,18 +378,20 @@ jQuery.xhr = function( _native ) {
 		// We're done
 		_setState( 4 );
 		
-		// Success
+		// Success/Error
-		_callbacksLists.success.fire( isSuccess , _callbackContext , success, statusText, xhr);
+		if ( isSuccess ) {
-		if ( isSuccess && _s.global ) {
+			_deferred.fire( _callbackContext , [ success , statusText , xhr ] );
-			_globalEventContext.trigger( "ajaxSuccess", [xhr, _s, success] );
+		} else {
+			_deferred.fireReject( _callbackContext , [ xhr , statusText , error ] );
 		}
-		// Error
+		
-		_callbacksLists.error.fire( ! isSuccess , _callbackContext , xhr, statusText, error);
+		if ( _s.global ) {
-		if ( !isSuccess && _s.global ) {
+			_globalEventContext.trigger( "ajax" + ( isSuccess ? "Success" : "Error" ) , [ xhr , _s , isSuccess ? success : error ] );
-			_globalEventContext.trigger( "ajaxError", [xhr, _s, error] );	
 		}
+		
 		// Complete
-		_callbacksLists.complete.fire( 1 , _callbackContext, xhr, statusText);
+		_completeDeferred.fire( _callbackContext, [ xhr , statusText ] );
+		
 		if ( _s.global ) {
 			_globalEventContext.trigger( "ajaxComplete", [xhr, _s] );
 			// Handle the global AJAX counter
@@ -419,7 +424,8 @@ jQuery.xhr = function( _native ) {
 		// Callback stuff
 		callbackContext,
 		globalEventContext,
-		callbacksLists,
+		deferred,
+		completeDeferred,
 		// Headers (they are sent all at once)
 		requestHeaders,
 		// Response headers
@@ -596,135 +602,10 @@ jQuery.xhr = function( _native ) {
 	// Init data (so that we can bind callbacks early
 	reset(1);
 
-	// Install callbacks related methods
-	jQuery.each(callbacksLists, function(name) {
-		var list;
-		xhr[name] = function() {
-			list = callbacksLists[name];
-			if ( list ) {
-				list.bind.apply(list, arguments );
-			}
-			return this;
-		};
-	});
-	
 	// Return the xhr emulation
 	return xhr;
 };
 
-// Create a callback list
-function createCBList() {
-	
-	var functors = [],
-		autoFire = 0,
-		fireArgs,
-		list = {
-		
-			fire: function( flag , context ) {
-				
-				// Save info for later bindings
-				fireArgs = arguments;
-				
-				// Remove autoFire to keep bindings in order
-				autoFire = 0;
-					
-				var args = sliceFunc.call( fireArgs , 2 );
-					
-				// Execute callbacks
-				while ( flag && functors.length ) {
-					flag = functors.shift().apply( context , args ) !== false;
-				}
-					
-				// Clean if asked to stop
-				if ( ! flag ) {
-					clean();
-				}
-						
-				// Set autoFire
-				autoFire = 1;					
-			},
-			
-			bind: function() {
-				
-				var args = arguments,
-					i = 0,
-					length = args.length,
-					func;
-				
-				for ( ; i < length ; i++ ) {
-					
-					func = args[ i ];
-					
-					if ( jQuery.isArray(func) ) {
-						
-						list.bind.apply( list , func );
-						
-					} else if ( isFunction(func) ) {
-						
-						// Add if not already in
-						if ( ! pos( func ) ) {
-							functors.push( func );
-						}
-					}
-				}
-				
-				if ( autoFire ) {
-					list.fire.apply( list , fireArgs );
-				}
-			},
-			
-			unbind: function() {
-				
-				var i = 0,
-					args = arguments,
-					length = args.length,
-					func,					
-					position;
-					
-				if ( length ) {
-						
-					for( ; i < length ; i++ ) {
-						func = args[i];
-						if ( jQuery.isArray(func) ) {
-							list.unbind.apply(list,func);
-						} else if ( isFunction(func) ) {
-							position = pos(func);
-							if ( position ) {
-								functors.splice(position-1,1);
-							}
-						}
-					}
-				
-				} else {
-					
-					functors = [];
-				
-				}
-
-			}
-			
-		};
-
-	// Get the index of the functor in the list (1-based)
-	function pos( func ) {
-		for (var i = 0, length = functors.length; i < length && functors[i] !== func; i++) {
-		}
-		return i < length ? ( i + 1 ) : 0;
-	}
-		
-	// Clean the object
-	function clean() {
-		// Empty callbacks list
-		functors = [];
-		// Inhibit methods
-		for (var i in list) {
-			list[i] = jQuery.noop;
-		}
-	}
-				
-	return list;
-}
-
 jQuery.extend(jQuery.xhr, {
 	
 	// Add new prefilter

test/unit/core.js

@@ -902,3 +902,253 @@ test("jQuery.parseJSON", function(){
 		ok( true, "Test malformed JSON string." );
 	}
 });
+
+test("jQuery._deferred()", function() {
+	
+	expect( 14 );
+	
+	var deferred,
+		object,
+		test;
+	
+	deferred = jQuery._deferred();
+		
+	test = false;
+		
+	deferred.then( function( value ) {
+		equals( value , "value" , "Test pre-resolve callback" );
+		test = true;
+	} );
+	
+	deferred.resolve( "value" );
+	
+	ok( test , "Test pre-resolve callbacks called right away" );
+
+	test = false;
+	
+	deferred.then( function( value ) {
+		equals( value , "value" , "Test post-resolve callback" );
+		test = true;
+	} );
+	
+	ok( test , "Test post-resolve callbacks called right away" );
+	
+	deferred.cancel();
+	
+	test = true;
+	
+	deferred.then( function() {
+		ok( false , "Manual cancel was ignored" );
+		test = false;
+	} );
+	
+	ok( test , "Test manual cancel" );
+	
+	deferred = jQuery._deferred().then( function() {
+		return false;
+	} );
+	
+	deferred.resolve();
+	
+	test = true;
+	
+	deferred.then( function() {
+		test = false;
+	} );
+	
+	ok( test , "Test cancel by returning false" );
+
+	try {
+		deferred = jQuery._deferred().resolve().then( function() {
+			throw "Error";
+		} , function() {
+			ok( false , "Test deferred cancel on exception" );
+		} );
+	} catch( e ) {
+		strictEqual( e , "Error" , "Test deferred propagates exceptions");
+		deferred.then();
+	}
+	
+	test = "";
+	deferred = jQuery._deferred().then( function() {
+		
+		test += "A";
+		
+	}, function() {
+		
+		test += "B";
+		
+	} ).resolve();
+	
+	strictEqual( test , "AB" , "Test multiple then parameters" );
+	
+	test = "";
+	
+	deferred.then( function() {
+		
+		deferred.then( function() {
+			
+			test += "C";
+			
+		} );
+		
+		test += "A";
+		
+	}, function() {
+		
+		test += "B";
+	} );
+	
+	strictEqual( test , "ABC" , "Test then callbacks order" );
+	
+	deferred = jQuery._deferred( false ).resolve().cancel();
+	
+	deferred.then( function() {
+		ok( true , "Test non-cancellable deferred not cancelled manually");
+		return false;
+	} );
+
+	deferred.then( function() {
+		ok( true , "Test non-cancellable deferred not cancelled by returning false");
+	} );
+	
+	try {
+		deferred.then( function() {
+			throw "Error";
+		} , function() {
+			ok( true , "Test non-cancellable deferred keeps callbacks after exception" );
+		} );
+	} catch( e ) {
+		strictEqual( e , "Error" , "Test non-cancellable deferred propagates exceptions");
+		deferred.then();
+	}
+	
+	deferred = jQuery._deferred();
+	
+	deferred.fire( jQuery , [ document ] ).then( function( doc ) {
+		ok( this === jQuery && arguments.length === 1 && doc === document , "Test fire context & args" );
+	});
+});
+
+test("jQuery.deferred()", function() {
+	
+	expect( 8 );
+	
+	jQuery.deferred( function( defer ) {
+		strictEqual( this , defer , "Defer passed as this & first argument" );
+		this.resolve( "done" );
+	}).then( function( value ) {
+		strictEqual( value , "done" , "Passed function executed" );
+	});
+	
+	jQuery.deferred().resolve().then( function() {
+		ok( true , "Success on resolve" );
+	}).fail( function() {
+		ok( false , "Error on resolve" );
+	});
+	
+	jQuery.deferred().reject().then( function() {
+		ok( false , "Success on reject" );
+	}).fail( function() {
+		ok( true , "Error on reject" );
+	});
+	
+	var flag = true;
+	
+	jQuery.deferred().resolve().cancel().then( function() {
+		ok( flag = false , "Success on resolve/cancel" );
+	}).fail( function() {
+		ok( flag = false , "Error on resolve/cancel" );
+	});
+	
+	ok( flag , "Cancel on resolve" );
+	
+	flag = true;
+	
+	jQuery.deferred().reject().cancel().then( function() {
+		ok( flag = false , "Success on reject/cancel" );
+	}).fail( function() {
+		ok( flag = false , "Error on reject/cancel" );
+	});
+	
+	ok( flag , "Cancel on reject" );
+	
+	jQuery.deferred( false ).resolve().then( function() {
+		return false;
+	} , function() {
+		ok( true , "Not cancelled on resolve" );
+	});
+	
+	jQuery.deferred( false ).reject().fail( function() {
+		return false;
+	} , function() {
+		ok( true , "Not cancelled on reject" );
+	});
+	
+});
+	
+test("jQuery.isDeferred()", function() {
+	
+	expect( 11 );
+	
+	var object1 = { then: function() { return this; } },
+		object2 = { then: function() { return this; } };
+		
+	object2.then._ = [];
+	
+	// The use case that we want to match
+	ok(jQuery.isDeferred(jQuery._deferred()), "Simple deferred");
+	ok(jQuery.isDeferred(jQuery.deferred()), "Failable deferred");
+	
+	// Some other objects
+	ok(!jQuery.isDeferred(object1), "Object with then & no marker");
+	ok(!jQuery.isDeferred(object2), "Object with then & marker");
+	
+	// Not objects shouldn't be matched
+	ok(!jQuery.isDeferred(""), "string");
+	ok(!jQuery.isDeferred(0) && !jQuery.isDeferred(1), "number");
+	ok(!jQuery.isDeferred(true) && !jQuery.isDeferred(false), "boolean");
+	ok(!jQuery.isDeferred(null), "null");
+	ok(!jQuery.isDeferred(undefined), "undefined");
+	
+	object1 = {custom: jQuery._deferred().then};
+	
+	ok(!jQuery.isDeferred(object1) , "custom method name not found automagically");
+	ok(jQuery.isDeferred(object1,"custom") , "custom method name");
+});
+
+test("jQuery.when()", function() {
+	
+	expect( 5 );
+	
+	var cache, i, deferred = { done: jQuery.deferred().resolve( 1 ).then };
+	
+	for( i = 1 ; i < 3 ; i++ ) {
+		jQuery.when( cache || jQuery.deferred( function() {
+			this.resolve( i );
+		}) ).then( function( value ) {
+			strictEqual( value , 1 , "Function executed" + ( i > 1 ? " only once" : "" ) );
+			cache = value;
+		}).fail( function() {
+			ok( false , "Fail called" );
+		});
+	}
+	
+	cache = 0;
+
+	for( i = 1 ; i < 3 ; i++ ) {
+		jQuery.when( cache || deferred , "done" ).done( function( value ) {
+			strictEqual( value , 1 , "Custom method: resolved" + ( i > 1 ? " only once" : "" ) );
+			cache = value;
+		}).fail( function() {
+			ok( false , "Custom method: fail called" );
+		});
+	}
+	
+	stop();
+	
+	jQuery.when( jQuery( document ) , "ready" ).then( function( test ) {
+		strictEqual( test , jQuery , "jQuery.fn.ready recognized as a deferred" );
+		start();
+	});
+});