lib/dojo/promise/first.js.uncompressed.js

   1 define("dojo/promise/first", [
   2         "../_base/array",
   3         "../Deferred",
   4         "../when"
   5 ], function(array, Deferred, when){
   6         "use strict";
   7
   8         // module:
   9         //              dojo/promise/first
  10
  11         var forEach = array.forEach;
  12
  13         return function first(objectOrArray){
  14                 // summary:
  15                 //              Takes multiple promises and returns a new promise that is fulfilled
  16                 //              when the first of these promises is fulfilled.
  17                 // description:
  18                 //              Takes multiple promises and returns a new promise that is fulfilled
  19                 //              when the first of these promises is fulfilled. Canceling the returned
  20                 //              promise will *not* cancel any passed promises. The promise will be
  21                 //              fulfilled with the value of the first fulfilled promise.
  22                 // objectOrArray: Object|Array?
  23                 //              The promises are taken from the array or object values. If no value
  24                 //              is passed, the returned promise is resolved with an undefined value.
  25                 // returns: dojo/promise/Promise
  26
  27                 var array;
  28                 if(objectOrArray instanceof Array){
  29                         array = objectOrArray;
  30                 }else if(objectOrArray && typeof objectOrArray === "object"){
  31                         array = [];
  32                         for(var key in objectOrArray){
  33                                 if(Object.hasOwnProperty.call(objectOrArray, key)){
  34                                         array.push(objectOrArray[key]);
  35                                 }
  36                         }
  37                 }
  38
  39                 if(!array || !array.length){
  40                         return new Deferred().resolve();
  41                 }
  42
  43                 var deferred = new Deferred();
  44                 forEach(array, function(valueOrPromise){
  45                         when(valueOrPromise, deferred.resolve, deferred.reject);
  46                 });
  47                 return deferred.promise;        // dojo/promise/Promise
  48         };
  49 });