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Deferred: Backwards-compatible standards interoperability

Browse Source 
Fixes gh-1722
Closes gh-1996

(cherry picked from commit 555a50d340)
This commit is contained in:
Richard Gibson
2014-12-29 14:14:13 -05:00
parent 9d255b3e50
commit 34f2563179
9 changed files with 701 additions and 117 deletions
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251
src/deferred.js
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@@ -4,14 +4,24 @@ define([
"./callbacks"
], function( jQuery, slice ) {
function Identity( v ) {
return v;
}
function Thrower( ex ) {
throw ex;
}
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") ]
// action, add listener, callbacks, .then handlers, final state
[ "resolve", "done", jQuery.Callbacks("once memory"),
jQuery.Callbacks("once memory"), "resolved" ],
[ "reject", "fail", jQuery.Callbacks("once memory"),
jQuery.Callbacks("once memory"), "rejected" ],
[ "notify", "progress", jQuery.Callbacks("memory"),
jQuery.Callbacks("memory") ]
],
state = "pending",
promise = {
@@ -22,12 +32,16 @@ jQuery.extend({
deferred.done( arguments ).fail( arguments );
return this;
},
then: function( /* fnDone, fnFail, fnProgress */ ) {
// Keep pipe for back-compat
pipe: function( /* fnDone, fnFail, fnProgress */ ) {
var fns = arguments;
return jQuery.Deferred(function( newDefer ) {
jQuery.each( tuples, function( i, tuple ) {
var fn = jQuery.isFunction( fns[ i ] ) && fns[ i ];
// deferred[ done | fail | progress ] for forwarding actions to newDefer
// deferred.done(function() { bind to newDefer or newDefer.resolve })
// deferred.fail(function() { bind to newDefer or newDefer.reject })
// deferred.progress(function() { bind to newDefer or newDefer.notify })
deferred[ tuple[1] ](function() {
var returned = fn && fn.apply( this, arguments );
if ( returned && jQuery.isFunction( returned.promise ) ) {
@@ -46,6 +60,157 @@ jQuery.extend({
fns = null;
}).promise();
},
then: function( onFulfilled, onRejected, onProgress ) {
var maxDepth = 0;
function resolve( depth, deferred, handler, special ) {
return function() {
var that = this === promise ? undefined : this,
args = arguments,
mightThrow = function() {
var returned, then;
// Support: Promises/A+ section 2.3.3.3.3
// https://promisesaplus.com/#point-59
// Ignore double-resolution attempts
if ( depth < maxDepth ) {
return;
}
returned = handler.apply( that, args );
// Support: Promises/A+ section 2.3.1
// https://promisesaplus.com/#point-48
if ( returned === deferred.promise() ) {
throw new TypeError( "Thenable self-resolution" );
}
// Support: Promises/A+ sections 2.3.3.1, 3.5
// https://promisesaplus.com/#point-54
// https://promisesaplus.com/#point-75
// Retrieve `then` only once
then = returned &&
// Support: Promises/A+ section 2.3.4
// https://promisesaplus.com/#point-64
// Only check objects and functions for thenability
( typeof returned === "object" ||
typeof returned === "function" ) &&
returned.then;
// Handle a returned thenable
if ( jQuery.isFunction( then ) ) {
// Special processors (notify) just wait for resolution
if ( special ) {
then.call(
returned,
resolve( maxDepth, deferred, Identity, special ),
resolve( maxDepth, deferred, Thrower, special )
);
// Normal processors (resolve) also hook into progress
} else {
// ...and disregard older resolution values
maxDepth++;
then.call(
returned,
resolve( maxDepth, deferred, Identity, special ),
resolve( maxDepth, deferred, Thrower, special ),
resolve( maxDepth, deferred, Identity,
deferred.notify )
);
}
// Handle all other returned values
} else {
// Only substitue handlers pass on context
// and multiple values (non-spec behavior)
if ( handler !== Identity ) {
that = undefined;
args = [ returned ];
}
// Process the value(s)
// Default process is resolve
( special || deferred.resolveWith )(
that || deferred.promise(), args );
}
},
// Only normal processors (resolve) catch and reject exceptions
process = special ?
mightThrow :
function() {
try {
mightThrow();
} catch ( e ) {
// Support: Promises/A+ section 2.3.3.3.4.1
// https://promisesaplus.com/#point-61
// Ignore post-resolution exceptions
if ( depth + 1 >= maxDepth ) {
// Only substitue handlers pass on context
// and multiple values (non-spec behavior)
if ( handler !== Thrower ) {
that = undefined;
args = [ e ];
}
deferred.rejectWith( that || deferred.promise(),
args );
}
}
};
// Support: Promises/A+ section 2.3.3.3.1
// https://promisesaplus.com/#point-57
// Re-resolve promises immediately to dodge false rejection from
// subsequent errors
if ( depth ) {
process();
} else {
setTimeout( process );
}
};
}
return jQuery.Deferred(function( newDefer ) {
// fulfilled_handlers.add( ... )
tuples[ 0 ][ 3 ].add(
resolve(
0,
newDefer,
jQuery.isFunction( onFulfilled ) ?
onFulfilled :
Identity
)
);
// rejected_handlers.add( ... )
tuples[ 1 ][ 3 ].add(
resolve(
0,
newDefer,
jQuery.isFunction( onRejected ) ?
onRejected :
Thrower
)
);
// progress_handlers.add( ... )
tuples[ 2 ][ 3 ].add(
resolve(
0,
newDefer,
jQuery.isFunction( onProgress ) ?
onProgress :
Identity,
newDefer.notifyWith
)
);
}).promise();
},
// Get a promise for this deferred
// If obj is provided, the promise aspect is added to the object
promise: function( obj ) {
@@ -54,32 +219,50 @@ jQuery.extend({
},
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 ];
stateString = tuple[ 4 ];
// promise[ done | fail | progress ] = list.add
// promise.done = list.add
// promise.fail = list.add
// promise.progress = list.add
promise[ tuple[1] ] = list.add;
// Handle state
if ( stateString ) {
list.add(function() {
// state = [ resolved | rejected ]
state = stateString;
list.add(
function() {
// state = "resolved" (i.e., fulfilled)
// state = "rejected"
state = stateString;
},
// [ reject_list | resolve_list ].disable; progress_list.lock
}, tuples[ i ^ 1 ][ 2 ].disable, tuples[ 2 ][ 2 ].lock );
// rejected_callbacks.disable
// fulfilled_callbacks.disable
tuples[ i ^ 1 ][ 2 ].disable,
// progress_callbacks.lock
tuples[ 2 ][ 2 ].lock
);
}
// deferred[ resolve | reject | notify ]
// fulfilled_handlers.fire
// rejected_handlers.fire
// progress_handlers.fire
list.add( tuple[ 3 ].fire );
// deferred.resolve = function() { deferred.resolveWith(...) }
// deferred.reject = function() { deferred.rejectWith(...) }
// deferred.notify = function() { deferred.notifyWith(...) }
deferred[ tuple[0] ] = function() {
deferred[ tuple[0] + "With" ]( this === deferred ? promise : this, arguments );
return this;
};
// deferred.resolveWith = list.fireWith
// deferred.rejectWith = list.fireWith
// deferred.notifyWith = list.fireWith
deferred[ tuple[0] + "With" ] = list.fireWith;
});
@@ -97,7 +280,8 @@ jQuery.extend({
// Deferred helper
when: function( subordinate /* , ..., subordinateN */ ) {
var i = 0,
var method,
i = 0,
resolveValues = slice.call( arguments ),
length = resolveValues.length,
@@ -107,7 +291,7 @@ jQuery.extend({
// the master Deferred.
// If resolveValues consist of only a single Deferred, just use that.
deferred = remaining === 1 ? subordinate : jQuery.Deferred(),
master = remaining === 1 ? subordinate : jQuery.Deferred(),
// Update function for both resolve and progress values
updateFunc = function( i, contexts, values ) {
@@ -115,14 +299,12 @@ jQuery.extend({
contexts[ i ] = this;
values[ i ] = arguments.length > 1 ? slice.call( arguments ) : value;
if ( values === progressValues ) {
deferred.notifyWith( contexts, values );
} else if ( !(--remaining) ) {
deferred.resolveWith( contexts, values );
master.notifyWith( contexts, values );
} else if ( !( --remaining ) ) {
master.resolveWith( contexts, values );
}
};
},
progressValues, progressContexts, resolveContexts;
// add listeners to Deferred subordinates; treat others as resolved
@@ -131,11 +313,22 @@ jQuery.extend({
progressContexts = new Array( length );
resolveContexts = new Array( length );
for ( ; i < length; i++ ) {
if ( resolveValues[ i ] && jQuery.isFunction( resolveValues[ i ].promise ) ) {
resolveValues[ i ].promise()
if ( resolveValues[ i ] &&
jQuery.isFunction( (method = resolveValues[ i ].promise) ) ) {
method.call( resolveValues[ i ] )
.progress( updateFunc( i, progressContexts, progressValues ) )
.done( updateFunc( i, resolveContexts, resolveValues ) )
.fail( deferred.reject );
.fail( master.reject );
} else if ( resolveValues[ i ] &&
jQuery.isFunction( (method = resolveValues[ i ].then) ) ) {
method.call(
resolveValues[ i ],
updateFunc( i, resolveContexts, resolveValues ),
master.reject,
updateFunc( i, progressContexts, progressValues )
);
} else {
--remaining;
}
@@ -144,10 +337,10 @@ jQuery.extend({
// if we're not waiting on anything, resolve the master
if ( !remaining ) {
deferred.resolveWith( resolveContexts, resolveValues );
master.resolveWith( resolveContexts, resolveValues );
}
return deferred.promise();
return master.promise();
}
});