CODEWITHSUNDEEP
javascripthtmldom-events
Ambiguities
Ambiguities

Reputation: 415

Uncaught typeerror cannot read property 'body' of undefined

I am having a hard time figuring out why I am getting this error. I made sure that the JavaScript is loaded after the html is, I have even tried replacing this.doc and this.win with just document and window and it has not changed the result. Here is the code I am working with. It is implemented in <head> through <script src="window.js" type="text/javascript"></script> (I have also tried it at the end of the doc)

Window = function(doc, win)
{
    this.doc = doc;
    this.win = win;
    
    this.resize();
    this.win.addEventListener('resize', this.resize);
}

Window.prototype = 
{
    resize: function()
    {
        this.doc.body.innerHTML = window.innerHeight;
    }
};

window.onload = new Window(document, window);

Any help would be much appreciated.

Upvotes: 0

Views: 2108

Answers (1)

Denys S&#233;guret
Denys S&#233;guret

Reputation: 382274

That's because this isn't the Window object when the callback is called but the global object (window). A solution would be to bind the function :

this.win.addEventListener('resize', this.resize.bind(this));

If you really need to be compatible with IE8, do this :

var _this = this;
this.win.addEventListener('resize', function(){_this.resize() });

But your global construct raises alarms. Be careful not to build useless verbose classes "java-style". Do you really need this Window class ?

Upvotes: 3

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