Backbone.Marionette - show method not rendering properly.. somethings goes wrong - backbone.js

Question

In my app, I am getting the show method issue. something is wrongly going on with my app. But i couldn't able to find that.
in case if i do like this my view is properly rendering ( but this is wrong approach ):
regions:{
header:'header',
content:'section',
footer:'footer'
},
initialize:function(){
console.log('initialized by layout')
},
renderRegions:function(options){
this.formData = _.defaults(options || {}, requireViews);
if(this.formData.headerView){ //this is true.
this.headerView();
this.renderHeaderView();
}
},
headerView:function(){
this.appHeaderView = new AppHeaderView({model:this.model});
return this.appHeaderView;
},
renderHeaderView:function(){
$(this.header.el).html(this.appHeaderView.render().el) //working fine
//but this is not workig: this.header.show(this.appHeaderView)..why not working?
}
why i use the "this.header.show" - nothing is appending to header.
Any one highlight me what is wrong i do here?
I have simplified my total process, and added in Jsfiddle here is the link:
Live Demo Here

Answer 1

You have a few issues in your code:
A view's model needs to be instantiated, not just the model class.
There is absolutely no reason for you to overwrite the ItemView's render method with what you had.
Your order of operations is wrong. show can only be called after the Layout is in the DOM already.
Here's the main thing that fixes your issue:
var Controller = Backbone.Marionette.Controller.extend({
initialize:function(){
this.layout = new Layout;
$('#wrapper').html(this.layout.render().el);
this.layout.renderRegions();
}
});
Updated FIDDLE
Another option (and something I find myself doing often) is to render the regions using the onShow method of the layout.