Backbone Collection Issue - backbone.js

Question

I have a Backbone App with 3 model which have nested collections:
Models Structure:
Layout extends Backbone.Model
-> sections: new Sections extends Backbone.Collection
Section extends Backbone.Model
-> rows: new Rows extends Backbone.Collection
Now if I have two section model in layout and I go and add row model to one of the Section.rows collection, it is adding it to both sections.
BTW, I am adding it from a view on an event.
Thanks in Advance.

Answer 1

got a workaround. I could reproduce your workflow by adding defaults property to my models.
like this:
var Section = Backbone.Model.extend({
defaults: {
rows: new Rows
}
});
var Layout = Backbone.Model.extend({
defaults: {
sections: new Sections
}
});
then really, if i add new row to rows to one of my section its appear to adding to all sections rows collection. So i do this (rude example):
var Row = Backbone.Model.extend({
defaults: {
rowData: 0
}
});
var Rows = Backbone.Collection.extend({
model: Row
});
var Section = Backbone.Model.extend({
//defaults: {
// rows: new Rows
//}
});
var Sections = Backbone.Collection.extend({
model: Section
});
var Layout = Backbone.Model.extend({
//defaults: {
// sections: new Sections
//}
});
var LayoutView = Backbone.View.extend({
});
var lView = new LayoutView({ model: new Layout });
lView.model.set('sections',new Sections());
var sections = lView.model.get('sections');
sections.add({id: 1, name: 's1',rows: new Rows() });
sections.add({id: 2, name: 's2',rows: new Rows() })
var rows = sections.get(1).get('rows');
rows.add({id:'r1',rowsData: 10});
console.log(lView.model.toJSON());

Answer 2

#aleha you are right the issue is of the default attribute settings in Model. As they share the same memoery space(javascript: pass by reference not by value ).
So what I did is in the initialize function
initialize: function() {
this.set( 'rows', new Rows() );
}
So, no need to do it like you are doing above:
sections.add({id: 1, name: 's1',rows: new Rows() });
Hence resolved and automate :)
Thanks for the help though.