Question

How do I call class methods from functions within the class? My code is:

var myExtension = {

    init: function() {
        // Call onPageLoad
    },  

    onPageLoad: function() {  
        // Do something    
    },

}  

I’ve tried …

onPageLoad();

… from within the init method but it’s saying it’s not defined.

I’m not having much luck with google because I don’t understand the syntax used. All the JS OOP examples I find online are in a different format. I’m using the format Mozilla use for extension development.

Answer 1

Assuming that you have called init like this:

myExtension.init();

then it should be:

init: function() {
    // before
    this.onPageLoad();
    // after
}

But in Javascript functions are not actually bound to objects and you can call any function on any other object, like this:

myExtension.init.call(anotherObject); // or
myExtension.init.apply(anotherObject);

In this example this within init would be anotherObject, which doesn’t have onPageLoad defined. If you want to support this kind of usage you’ll have to manually reference the initial object:

init: function() {
    // before
    myExtension.onPageLoad();
    // after
}