Say I have a Backbone Relational model representing a crowd - it has a related collection of People, each of model type Person:
CrowdModel = Backbone.RelationalModel.extend({
relations: [{
type: Backbone.HasMany,
key: 'People',
relatedModel: 'PersonModel',
collectionType: 'Backbone.Collection'
}]
});
Each Person has a related collection of Children, a child also being of model type Person:
PersonModel = Backbone.RelationalModel.extend({
relations: [{
type: Backbone.HasMany,
key: 'Children',
relatedModel: 'PersonModel',
collectionType: 'Backbone.Collection'
}]
});
Now, in my view, I'd like to listen to a change event - let's call it "Hungry" - on any of the models.
CrowdView = Backbone.View.extend({
initialize: function () {
this.listenTo(this.model.get("People"), 'change:Hungry', this.hungryChange);
},
hungryChange: function(model, val, options) {
if(val) console.log("Somebody's hungry!");
}
});
This will fire if any of the People are hungry, but I'm looking to find a way in the view to also listen for the hungry event on any of the Children. Is there some way of bubbling this up?
jsfiddle here: http://jsfiddle.net/fnj58/1/
Sorry for the contrived example - this really has to do with a model representing a tree of checkboxes, but it's easier to describe this way.
You should bubble the event from the Person.
Add handler for childHungry in CrowdView init function
CrowdView = Backbone.View.extend({
....
initialize: function () {
this.listenTo(this.model.get("People"), 'childHungry', function(){
console.log("Someone's child is hungry");
});// listening to child hungry
this.listenTo(this.model.get("People"), 'change:Hungry', this.hungryChange);
},
});
Person model should listen to his children and trigger that he has a child hungry
PersonModel = Backbone.RelationalModel.extend({
....
initialize: function(){
this.listenTo(this.get("Children"), 'change:Hungry', this.childHungry);
},
childHungry: function(){
this.trigger("childHungry");
}
By the Way: if you don't want the Crowd to distinguish between a child hungry or a person hungry you could also just trigger change:Hungry on the above childHungry function and keep your versiono CrowdView (See http://jsfiddle.net/fnj58/2/)