Question

I am having big trouble fixing this error.

I have a view in Backbone.js and I want to bind some actions on it with keyboard events.

Here is my view :

window.PicturesView = Backbone.View.extend({
    initialize : function() {
        $(document).on('keydown', this.keyboard, this);
    },
    remove : function() {
        $(document).off('keydown', this.keyboard, this);
    },
    render : function(eventName) {
        // blah blah blah
    },
    next : function() {
        // blah
    },
    prev : function() {
        // blah
    },
    keyboard : function(e) {
        console.log(e.keyCode);
        if (e.keyCode == 37) {
            this.prev();
            return false;
        }
        if (e.keyCode == 39) {
            this.next();
            return false;
        }
    }
});

When I press the keyboard, I get this error :
Uncaught TypeError: Object [object Object] has no method 'apply'
that is triggered by jQuery.

After reading this : Uncaught TypeError: Object [object Object] has no method 'apply'

I also tried :
$(document).on('keydown', function(e) {
this.keyboard(e);
}, this);
but it still gives me the same error.

And :
$(document).on('keydown', 'keyboard', this);
in the events : { 'event' : 'action' } style
but it doesn’t do anything.

I could probably find some hack by using jQuery only somewhere else in my code, but since I am not expert in event handling and Backbone, I want to run it the nice way.

I hope I’m clear, thanks

Answer 1

@roatin-marth was right. The “on” function that was applying wasn’t the backbone one as I expected, which allows to pass the context as a parameter :
$(document).on('keydown', this.keyboard, this);

Since it’s a jQuery selector, it’s the jQuery on that applies. Hence I need a proxy to link with context:
$(document).on('keydown',$.proxy(this.keyboard,this));

All good, thanks for the help.