CODEWITHSUNDEEP
javascriptjquerypromisejquery-deferred
aherrick
aherrick

Reputation: 20179

jQuery Deferred Won't Resolve

I have a service helper setup like this:

var service = {

getSettings: function () {

    var that = this,
     deferred = $.Deferred();

    that.getThingOne().done(function (data) {

        that.getThingTwo(data.Element).done(function (data) {

            deferred.resolve(data);
        });
    });
    return deferred.promise();
},

getThingTwo: function (elm) {

    return $.getJSON('http://ajax-call-here');
},

getThingOne: function () {

    var deferred = $.Deferred();
    navigator.geolocation.getCurrentPosition(deferred.resolve, deferred.reject, {
        enableHighAccuracy: true
    });
    return deferred.promise();
}

};

When I call into it doing something like this I never reach below. What is going on?

service.getSettings().done(function(data) {

    // never reach here
});

Upvotes: 0

Views: 516

Answers (1)

Benjamin Gruenbaum
Benjamin Gruenbaum

Reputation: 276596

First - You can simplify your code quite a bit. Promises chain and are an abstraction on the notion of continuation itself. 

getSettings: function () {
    var that = this; // this line can be avoided as well
    return this.getThingOne().then(function (data) {
        // returning from a `.then` will cause the promise to resolve with that
        // return value
        return that.getThingTwo(data.Element); 
    });
}

Second, your promisification doesn't work. Try to preserve the context:

getThingOne: function () {

    var deferred = $.Deferred();
    navigator.geolocation.getCurrentPosition(
    function(v){ deferred.resolve(v); }, // preserve context
    function(e){ deferred.reject(e;) }, { // here too
        enableHighAccuracy: true
    });
    return deferred.promise();
}

Because of this - the promise never got resolved.

Upvotes: 2

Related Questions