Uncaught TypeError: Cannot read property 'app' of undefined

Question

I have a composite view:

var resultView = Marionette.CompositeView.extend({
        template : ResultPanel,
        itemView : ResultItemView,
        initialize : function() {
            ...
        },
        itemViewOptions : {
            app : this.options.app
        },

I just want to assign this view's app property to itemView's app property. So i can use this view's app from other view. But I'm getting this error: Uncaught TypeError: Cannot read property 'app' of undefined. What am i doing wrong? Is there another way in order to do this?

Answer 1

possiblity #1: this.option is not yet set when your code executes.

possibility #2: maybe 'this' is not what you expect it to be. assign var that = this; before and use 'that' instead of 'this'.

or assign var _options = this.options; before extend() and use _options in the extend.

Answer 2

options will be generated from the object that you supply to the constructor of your view. It includes everything except for things like model and collection

var rv = new resultView({model: something, app: something})

Which can then be accessed like so

var resultView = Marionette.CompositeView.extend({
        itemView : ResultItemView,
        initialize : function(options) {
             this.app = options.something;    
        },
        itemViewOptions : {
            app : this.options.app
        },

If you want to refer to these options in another method, you will need to attach the required variables to the view ( this ) itself.

You can't access things like the model from the options parameter, however they will automatically be attached to your view