aboutsummaryrefslogtreecommitdiffstats
path: root/src/deferred.js
blob: f509a9acacfba38108f890c6b94afbe9b6ea5539 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
(function( jQuery ) {

var // Static reference to slice
	sliceDeferred = [].slice;

jQuery.extend({

	Deferred: function( func ) {
		var tuples = [
				// action, add listener, listener list, final state
				[ "resolve", "done", jQuery.Callbacks("once memory"), "resolved" ],
				[ "reject", "fail", jQuery.Callbacks("once memory"), "rejected" ],
				[ "notify", "progress", jQuery.Callbacks("memory") ]
			],
			state = "pending",
			promise = {
				state: function() {
					return state;
				},
				always: function() {
					deferred.done( arguments ).fail( arguments );
					return this;
				},
				then: function( /* fnDone, fnFail, fnProgress */ ) {
					var fns = arguments;
					return jQuery.Deferred(function( newDefer ) {
						jQuery.each( tuples, function( i, tuple ) {
							var action = tuple[ 0 ],
								fn = fns[ i ];
							// deferred[ done | fail | progress ] for forwarding actions to newDefer
							deferred[ tuple[1] ]( jQuery.isFunction( fn ) ?
								function() {
									var returned = fn.apply( this, arguments );
									if ( returned && jQuery.isFunction( returned.promise ) ) {
										returned.promise()
											.done( newDefer.resolve )
											.fail( newDefer.reject )
											.progress( newDefer.notify );
									} else {
										newDefer[ action + "With" ]( this === deferred ? newDefer : this, [ returned ] );
									}
								} :
								newDefer[ action ]
							);
						});
						fns = null;
					}).promise();
				},
				// Get a promise for this deferred
				// If obj is provided, the promise aspect is added to the object
				promise: function( obj ) {
					return typeof obj === "object" ? jQuery.extend( obj, promise ) : promise;
				}
			},
			deferred = {};

		// Keep pipe for back-compat
		promise.pipe = promise.then;

		// Add list-specific methods
		jQuery.each( tuples, function( i, tuple ) {
			var list = tuple[ 2 ],
				stateString = tuple[ 3 ];

			// promise[ done | fail | progress ] = list.add
			promise[ tuple[1] ] = list.add;

			// Handle state
			if ( stateString ) {
				list.add(function() {
					// state = [ resolved | rejected ]
					state = stateString;

				// [ reject_list | resolve_list ].disable; progress_list.lock
				}, tuples[ i ^ 1 ][ 2 ].disable, tuples[ 2 ][ 2 ].lock );

				// <DEPRECATED> [ isResolved | isRejected ] = [ resolve_list | reject_list ].fired
				promise[ "isR" + stateString.substr( 1 ) ] = list.fired;
			}

			// deferred[ resolve | reject | notify ] = list.fire
			deferred[ tuple[0] ] = list.fire;
			deferred[ tuple[0] + "With" ] = list.fireWith;
		});

		// Make the deferred a promise
		promise.promise( deferred );

		// Call given func if any
		if ( func ) {
			func.call( deferred, deferred );
		}

		// All done!
		return deferred;
	},

	// Deferred helper
	when: function( subordinate /* , ..., subordinateN */ ) {
		var i = 0,
			resolveValues = sliceDeferred.call( arguments ),
			length = resolveValues.length,
			progressValues = new Array( length ),

			// the count of uncompleted subordinates
			remaining = length !== 1 || ( subordinate && jQuery.isFunction( subordinate.promise ) ) ? length : 0,

			// the master Deferred. If resolveValues consist of only a single Deferred, just use that.
			deferred = remaining === 1 ? subordinate : jQuery.Deferred(),
			promise = deferred.promise(),

			// Update function for both resolve and progress values
			updateFunc = function( i, arr ) {
				return function( value ) {
					arr[ i ] = arguments.length > 1 ? sliceDeferred.call( arguments ) : value;
					if( arr === progressValues ) {
						deferred.notifyWith( promise, arr );
					} else if ( !( --remaining ) ) {
						deferred.resolveWith( promise, arr );
					}
				};
			};

		// add listeners to Deferred subordinates; treat others as resolved
		if ( length > 1 ) {
			for ( ; i < length; i++ ) {
				if ( resolveValues[ i ] && jQuery.isFunction( resolveValues[ i ].promise ) ) {
					resolveValues[ i ].promise()
						.done( updateFunc( i, resolveValues ) )
						.fail( deferred.reject )
						.progress( updateFunc( i, progressValues ) );
				} else {
					--remaining;
				}
			}
		}

		// if we're not waiting on anything, resolve the master
		if ( !remaining ) {
			deferred.resolveWith( deferred, resolveValues );
		}

		return promise;
	}
});

})( jQuery );