deferred.js 4.2 KB

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  1. jQuery.extend({
  2. Deferred: function( func ) {
  3. var tuples = [
  4. // action, add listener, listener list, final state
  5. [ "resolve", "done", jQuery.Callbacks("once memory"), "resolved" ],
  6. [ "reject", "fail", jQuery.Callbacks("once memory"), "rejected" ],
  7. [ "notify", "progress", jQuery.Callbacks("memory") ]
  8. ],
  9. state = "pending",
  10. promise = {
  11. state: function() {
  12. return state;
  13. },
  14. always: function() {
  15. deferred.done( arguments ).fail( arguments );
  16. return this;
  17. },
  18. then: function( /* fnDone, fnFail, fnProgress */ ) {
  19. var fns = arguments;
  20. return jQuery.Deferred(function( newDefer ) {
  21. jQuery.each( tuples, function( i, tuple ) {
  22. var action = tuple[ 0 ],
  23. fn = jQuery.isFunction( fns[ i ] ) && fns[ i ];
  24. // deferred[ done | fail | progress ] for forwarding actions to newDefer
  25. deferred[ tuple[1] ](function() {
  26. var returned = fn && fn.apply( this, arguments );
  27. if ( returned && jQuery.isFunction( returned.promise ) ) {
  28. returned.promise()
  29. .done( newDefer.resolve )
  30. .fail( newDefer.reject )
  31. .progress( newDefer.notify );
  32. } else {
  33. newDefer[ action + "With" ]( this === promise ? newDefer.promise() : this, fn ? [ returned ] : arguments );
  34. }
  35. });
  36. });
  37. fns = null;
  38. }).promise();
  39. },
  40. // Get a promise for this deferred
  41. // If obj is provided, the promise aspect is added to the object
  42. promise: function( obj ) {
  43. return obj != null ? jQuery.extend( obj, promise ) : promise;
  44. }
  45. },
  46. deferred = {};
  47. // Keep pipe for back-compat
  48. promise.pipe = promise.then;
  49. // Add list-specific methods
  50. jQuery.each( tuples, function( i, tuple ) {
  51. var list = tuple[ 2 ],
  52. stateString = tuple[ 3 ];
  53. // promise[ done | fail | progress ] = list.add
  54. promise[ tuple[1] ] = list.add;
  55. // Handle state
  56. if ( stateString ) {
  57. list.add(function() {
  58. // state = [ resolved | rejected ]
  59. state = stateString;
  60. // [ reject_list | resolve_list ].disable; progress_list.lock
  61. }, tuples[ i ^ 1 ][ 2 ].disable, tuples[ 2 ][ 2 ].lock );
  62. }
  63. // deferred[ resolve | reject | notify ]
  64. deferred[ tuple[0] ] = function() {
  65. deferred[ tuple[0] + "With" ]( this === deferred ? promise : this, arguments );
  66. return this;
  67. };
  68. deferred[ tuple[0] + "With" ] = list.fireWith;
  69. });
  70. // Make the deferred a promise
  71. promise.promise( deferred );
  72. // Call given func if any
  73. if ( func ) {
  74. func.call( deferred, deferred );
  75. }
  76. // All done!
  77. return deferred;
  78. },
  79. // Deferred helper
  80. when: function( subordinate /* , ..., subordinateN */ ) {
  81. var i = 0,
  82. resolveValues = core_slice.call( arguments ),
  83. length = resolveValues.length,
  84. // the count of uncompleted subordinates
  85. remaining = length !== 1 || ( subordinate && jQuery.isFunction( subordinate.promise ) ) ? length : 0,
  86. // the master Deferred. If resolveValues consist of only a single Deferred, just use that.
  87. deferred = remaining === 1 ? subordinate : jQuery.Deferred(),
  88. // Update function for both resolve and progress values
  89. updateFunc = function( i, contexts, values ) {
  90. return function( value ) {
  91. contexts[ i ] = this;
  92. values[ i ] = arguments.length > 1 ? core_slice.call( arguments ) : value;
  93. if( values === progressValues ) {
  94. deferred.notifyWith( contexts, values );
  95. } else if ( !( --remaining ) ) {
  96. deferred.resolveWith( contexts, values );
  97. }
  98. };
  99. },
  100. progressValues, progressContexts, resolveContexts;
  101. // add listeners to Deferred subordinates; treat others as resolved
  102. if ( length > 1 ) {
  103. progressValues = new Array( length );
  104. progressContexts = new Array( length );
  105. resolveContexts = new Array( length );
  106. for ( ; i < length; i++ ) {
  107. if ( resolveValues[ i ] && jQuery.isFunction( resolveValues[ i ].promise ) ) {
  108. resolveValues[ i ].promise()
  109. .done( updateFunc( i, resolveContexts, resolveValues ) )
  110. .fail( deferred.reject )
  111. .progress( updateFunc( i, progressContexts, progressValues ) );
  112. } else {
  113. --remaining;
  114. }
  115. }
  116. }
  117. // if we're not waiting on anything, resolve the master
  118. if ( !remaining ) {
  119. deferred.resolveWith( resolveContexts, resolveValues );
  120. }
  121. return deferred.promise();
  122. }
  123. });