Using this. in Promise callbacks

Question

I come from an object oriented world, but I'm trying to make a go of javascript.  I've created a class using WinJS.Class.define.  One of the methods makes a call to a webservice.  I'm using WinJS.xhr to make the call.

 

In promise returned by the xhr call I'd like to access some member variables of my class.  So something like this:

WinJS.xhr({ url: flickrURL }).then(
function (response)
{
     var test = this.classMember;
     var functionResult = this.someFunction();
},
function (response)
{
     ....
});

The problem is "this" is not my class but some other object.  Is there any way to do this?

 

Thank you,

Ricky

Answer 1

The trick here is to cache a reference to your object before doing the asynchronous callback:

 

var that = this;

WinJS.xhr(options).then(function(response) {
    that.someFunction(response);
}

Cheers,

-Jeff

Answer 2

Thank you!!!!