Getting models in nested collections in Backbonejs - backbone.js

Question

I'm working in a collection that contains a model with collections of "itself". For example:
[{
id: 1
name: "John",
children: [
{
id: 32
name: "Peter",
children: []
},
{
id: 54
name: "Mary",
children: [
{
id:12,
name: "Kevin"
}
]
},
]
}]
Let say that I want to get the Kevin "user" by its Id. But all that I have is the "first collection". How can I do that?? And about setting a user within a collection? Another thing: Its possible to get all the Kevin "parents" from him? Like Mary and John?
Does anyone has come to a issue like that?
Thanks a LOT

Answer 1

Well I've made a recursive function on the User's Collection that seems to solved the problem for now ( the best of this is that I can use for retrieve a "deep" model and change it.). Something like that ( if someone has any suggestions, be free to give it a opinion ):
findUserById: function(id) {
var self = new Backbone.Collection(this.toJSON());
return thisCollection(id, this);
function thisCollection(id, collection, array) {
var innerSelf = collection || this;
var thisArray = array || [];
for(var i = innerSelf.models.length; i--;) {
if(innerSelf.models[i].get('id') == id) {
return [innerSelf.models[i]].concat([thisArray]);
}else {
if(innerSelf.models[i].get('children').length > 0) {
thisArray.push(innerSelf.models[i]);
return thisCollection(id, innerSelf.models[i].get('children'), thisArray);
}else {
innerSelf.remove(innerSelf.models[i]);
return thisCollection(id, self, []);
}
}
}
}
}
Basically I return an array with 2 items. The first is the record that I'm looking for and the second is an array with the parents of this user.

Answer 2

Underscore (which is a Backbone dependency, so you already have it) is great for this sort of thing; if you use its "map" function (which Backbone provides as a method on Collection) with its find function, you can do the following:
findPersonInPeopleCollection: function(nameWeAreLookingFor) {
function findChildren(person) {
if (!person.children) return [person];
var children = _.map(person.children, function(child) {
foundPeople.push(findChildren(child);
})
return _.flatten(children);
}
var allPeople = _.flatten(myCollectionOfPeople.map(findChildren));
return _(allPeople).find(function(person) {
return person.get('name') == nameWeAreLookingFor;
}
}
If you wanted to store the parents initially you could either add logic to your "Person" model class's initialize function, eg.
var Person = Backbone.Model.extend({
initialize: function() {
_.each(this.get('children'), function(child) {
child.parent = this;
}, this);
}
});
You could also do something similar by overriding your collection's add method, or adding an event handler to it that triggers after people get added.