Error on crop - Sprite extended class

[NotAnExecutive]

Hi, guys.

First of all, I've found Phaser amazing. And though my knowledge of Javascript is pretty basic, almost everything has been done without too many problems.

 

I got a problem with sprite cropping.

So I extended Sprite...

var cropRect;var some_obj;Medidor = function(game, x, y, someObject) {      Phaser.Sprite.call(this, game, x, y, 'medidor');        [...]        this.cropEnabled = true;    cropRect = new Phaser.Rectangle(0, 0, this.width/2, this.height);    this.crop(cropRect);        [...]    game.add.existing(this);};Medidor.prototype = Object.create(Phaser.Sprite.prototype);  Medidor.prototype.constructor = Medidor;Medidor.prototype.update = function() {    [...]    this.updateCrop();};

But when I run the game, an error appears:

TypeError: this.crop is not a function

I have even followed the example here:

http://examples.phaser.io/_site/view_full.html?d=sprites&f=dynamic+crop.js&t=dynamic%20crop

 

I don't know what I am doing wrong :/

 

Any ideas?

 

Thanks in advance,