CODEWITHSUNDEEP
javascriptjquerypromisejquery-deferreddeferred
i.Nemiro
i.Nemiro

Reputation: 150

Resolve jquery deferred object with another deferred object

How to resolve one Deffered object with resolve state of another. Simple example and simple explanation please (saw a lot of difficult ones).

How I can resolve result promise with a foo(), without .done(..) and .fail(..)?

var result = $.Deferred();

/**
 * @returns {Deferred}
 */
var foo = function() {
  // ... something that returns deferred object at random moment of time
};

foo()
  .done(function(){result.resolve()})
  .fail(function(){result.reject()})
;

setTimeout(function() {
    result.reject();
}, 50);

setTimeout(function(){
    console.log('Result is:', result.state());
}, 100);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

Upvotes: 1

Views: 182

Answers (2)

collapsar
collapsar

Reputation: 17238

Your Deferred object def is superfluous (see the links given by Benajmin Gruenbaum why it's actually dangerous [silent fails]). Resolve/reject the result object:

var result = $.Deferred();
var foo = function() {
  return Math.random() > 0.5 ? result.resolve() : result.reject();
};

setTimeout(function(){
    document.write('Result is:', result.state());
}, 500);

foo();
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

Upvotes: 1

dfsq
dfsq

Reputation: 193261

You can use function passed in $.Deferred and resolve/reject deferred from inside:

var result = $.Deferred(function() {
    Math.random() > 0.5 ? this.resolve() : this.reject();
});

setTimeout(function(){
    document.write('Result is: ' + result.state());
}, 100);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

Upvotes: 2

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