Question

I have the following code that creates an object in JavaScript. It uses prototype to define functions and constructors.

function objectClass(){
    this.variables = new Array();
}

objectClass.prototype = 
{
    contructor: objectClass,

    setInfo: function(){
        $.ajax({
            url: "info.json",
            success: function(){
                //for each json element returned...
                this.variables.push(json[i]);
            }
        });
    }
    getInfo: function(){
        return this.variables;
    },
}

This is a similar example of what I am trying to do. I need to be able to return the array of variables when I call obj.getInfo(). It always throws an error. I believe it is because the “this” is referring to the scope of the ajax success function.

Any ideas on how to get it to reference the objects variable?

Answer 1

That’s correct, the this value is not automatically passed and thus not set to the instance. To force this, you can use the context property that $.ajax accepts:

$.ajax({
    context: this, // `this` is the instance here

This sets the this value inside the success callback to the one you specified.