Backbone.js - passing arguments through constructors

Question

Scenario:
I got an alert() saying undefined when I (try to) set the myVar variable through the Constructor. However i

Answer 1

Options passed into the constructor are automatically stored as this.options

var myView = Backbone.View.extend({

  myVar : 'Hello from inside',

  initialize: function() {
      alert(this.options.myVar);
  }
)};

new myView({myVar: 'Hello from outside'});

Answer 2

As of backbone 1.1.0, the options argument is no longer attached automatically to the view (see issue 2458 for discussion). You now need to attach the options of each view manually:

MyView = Backbone.View.extend({
    initialize: function(options) {
        _.extend(this, _.pick(options, "myVar", ...));
        // options.myVar is now at this.myVar
    }
});

new MyView({
    myVar: "Hello from outside"
    ...
});

Alternatively you can use this mini plugin to auto-attach white-listed options, like so:

MyView = BaseView.extend({
    options : ["myVar", ...] // options.myVar will be copied to this.myVar on initialize
});