Input event on class

[polo]

I try to implement a input event handler from an class inherited of Sprite class. See below

 

Rts.Unit = function Unit(game, x, y) {

    Phaser.Sprite.call(this, game, x, y, 'player');

    this.inputEnabled = true;

    this.selected = false;

    this.events.onInputDown.add(this.select);

    return this;

};

 

Rts.Unit.prototype = Object.create(Phaser.Sprite.prototype);

Rts.Unit.prototype.constructor = Rts.Unit;

 

Rts.Unit.prototype.dummy = function() {

    console.log("dummy");

}

 

Rts.Unit.prototype.select = function() {

    this.selected = true;

    this.dummy();

};

 

but it's doesnt work and raise error

"Uncaught TypeError: undefined is not a function"

 

My game is manage by state.

Regards

 

[ragnarok]

Most often, when I get such errors, it's because 'this' is not what I expect it to be.

 

The development tools should tell you which line the error occurs in.  Put a "console.log(this);" in the line before and restart. The next time the error comes up, take a look what 'this' really is and if it has the method you want. For if 'this' is your gamestate-object and you expect it to be 'game', try "this.game" instead.

[polo]

Thanks , that's true "this" is not what i expected in this context, i don't understand why in the event context i can't use a self reference to an object function. Why the "event" works in game -state context ?

[lewster32]

You can pass the context you need to the signal, like so:

this.events.onInputDown.add(this.select, this);

The second parameter is the context you want it to run in.

[ragnarok]

Thanks , that's true "this" is not what i expected in this context, i don't understand why in the event context i can't use a self reference to an object function. Why the "event" works in game -state context ?

 

You can (as Lewester pointed out), it's just, that 'this' act's really strange or someone coming from other langages. These links might be of interest:

 

http://www.quirksmode.org/js/this.html

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/this

[polo]

Thanks for all your support, it works like lewster32 explain.