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author | jaubourg <j@ubourg.net> | 2011-03-03 19:38:06 +0100 |
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committer | jaubourg <j@ubourg.net> | 2011-03-03 19:38:06 +0100 |
commit | 2d0bc7ce72ab8d64da0506a88c8cc543ce3ceaba (patch) | |
tree | 2079117d0da1dbe2500e3aa78c5f0ff60a453ba3 /src/deferred.js | |
parent | c1279895f3f33cacc08e508c2409b587c0e6a5a2 (diff) | |
download | jquery-2d0bc7ce72ab8d64da0506a88c8cc543ce3ceaba.tar.gz jquery-2d0bc7ce72ab8d64da0506a88c8cc543ce3ceaba.zip |
Moves Deferred-related code into a separate module. Context handling has been simplified in _Deferred.resolve and jQuery.when has been refactored for clarity (and minor optimization).
Diffstat (limited to 'src/deferred.js')
-rw-r--r-- | src/deferred.js | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/src/deferred.js b/src/deferred.js new file mode 100644 index 000000000..f0d7c08c5 --- /dev/null +++ b/src/deferred.js @@ -0,0 +1,169 @@ +(function( jQuery ) { + +var // Promise methods + promiseMethods = "then done fail isResolved isRejected promise".split( " " ), + // Static reference to slice + sliceDeferred = [].slice; + +jQuery.extend({ + // Create a simple deferred (one callbacks list) + _Deferred: function() { + 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 = { + + // done( f1, f2, ...) + done: function() { + if ( !cancelled ) { + var args = arguments, + i, + length, + elem, + type, + _fired; + if ( fired ) { + _fired = fired; + fired = 0; + } + for ( i = 0, length = args.length; i < length; i++ ) { + elem = args[ i ]; + type = jQuery.type( elem ); + if ( type === "array" ) { + deferred.done.apply( deferred, elem ); + } else if ( type === "function" ) { + callbacks.push( elem ); + } + } + if ( _fired ) { + deferred.resolveWith( _fired[ 0 ], _fired[ 1 ] ); + } + } + return this; + }, + + // resolve with given context and args + resolveWith: function( context, args ) { + if ( !cancelled && !fired && !firing ) { + // make sure args are available (#8421) + args = args || []; + firing = 1; + try { + while( callbacks[ 0 ] ) { + callbacks.shift().apply( context, args ); + } + } + finally { + fired = [ context, args ]; + firing = 0; + } + } + return this; + }, + + // resolve with this as context and given arguments + resolve: function() { + deferred.resolveWith( this, arguments ); + return this; + }, + + // Has this deferred been resolved? + isResolved: function() { + return !!( firing || fired ); + }, + + // Cancel + cancel: function() { + cancelled = 1; + callbacks = []; + return this; + } + }; + + return deferred; + }, + + // Full fledged deferred (two callbacks list) + Deferred: function( func ) { + var deferred = jQuery._Deferred(), + failDeferred = jQuery._Deferred(), + promise; + // Add errorDeferred methods, then and promise + jQuery.extend( deferred, { + then: function( doneCallbacks, failCallbacks ) { + deferred.done( doneCallbacks ).fail( failCallbacks ); + return this; + }, + fail: failDeferred.done, + rejectWith: failDeferred.resolveWith, + reject: failDeferred.resolve, + isRejected: failDeferred.isResolved, + // Get a promise for this deferred + // If obj is provided, the promise aspect is added to the object + promise: function( obj ) { + if ( obj == null ) { + if ( promise ) { + return promise; + } + promise = obj = {}; + } + var i = promiseMethods.length; + while( i-- ) { + obj[ promiseMethods[i] ] = deferred[ promiseMethods[i] ]; + } + return obj; + } + } ); + // Make sure only one callback list will be used + deferred.done( failDeferred.cancel ).fail( deferred.cancel ); + // Unexpose cancel + delete deferred.cancel; + // Call given func if any + if ( func ) { + func.call( deferred, deferred ); + } + return deferred; + }, + + // Deferred helper + when: function( firstParam ) { + var args = arguments, + i = 0, + length = args.length, + count = length, + deferred = length <= 1 && firstParam && jQuery.isFunction( firstParam.promise ) ? + firstParam : + jQuery.Deferred(); + function resolveFunc( i ) { + return function( value ) { + args[ i ] = arguments.length > 1 ? sliceDeferred.call( arguments, 0 ) : value; + if ( !( --count ) ) { + deferred.resolveWith( deferred, args ); + } + }; + } + if ( length > 1 ) { + for( ; i < length; i++ ) { + if ( args[ i ] && jQuery.isFunction( args[ i ].promise ) ) { + args[ i ].promise().then( resolveFunc(i), deferred.reject ); + } else { + --count; + } + } + if ( !count ) { + deferred.resolveWith( deferred, args ); + } + } else if ( deferred !== firstParam ) { + deferred.resolveWith( deferred, length ? [ firstParam ] : [] ); + } + return deferred.promise(); + } +}); + +})( jQuery ); |