List of Nested Models in Backbone-Forms

Question

I have a many to one relationship I'm trying to model with Backbone-Forms that I can't get to work.

The idea is that there are many foos that are attached to a single bar. The catch is every bar must have at least one foo. I want to be able to have a single form where you can create a bar, and as many foos as you want that are attached to that bar. The Backbone-Forms list would be perfect, unfortunately I don't know how to implement it with a nested model.

Thanks.

Nutbrown

Answer 1

I have never used Backbone-Forms before. But If I wanted to implement this without using this plugin I would go about this way.

I would have 2 Models and 2 Collection.

Models

• Bar
• Foo

Collections

• Bars
• Foos

I would have a parse method in Bar model that creates a Foo collection for each Model.

Views

• MainView (Passed in a Bars Collection) and Rendered
• BarsListView (Created from MainView passed in the Bar Collection)
• BarView (Passed in Bar Model)
• FooListView (Passed in Foo Collection)
• FooView (Passed in Foo Model)

Something in these lines.. This is just a rough example

// Models
var Foo = Backbone.Model.extend({});
var Foos = Backbone.Collection.extend({
    model : Foo
});
// Collections
var Bar = Backbone.Model.extend({
    initialize: function() {
        if(typeof this.foos === 'undefined') {
             this.foos = new Foos();
        }
    },
    // Parse method that will attach the 
    // foo list if available to the Bar Model
     parse: function(resp) {
        // Storing the collecting direcly on the Model
        this.foos = new Foos(resp.hobbies || null);
        delete resp.hobbies;
        return resp;
    }
});

var Bars = Backbone.Collection.extend({
    model : Bar
});

//Views
var FooView = Backbone.View.extend({
    tagName: 'li',
    className : 'foo',
    template: _.template($('#foo-template').html()),
    render: function() {
        this.$el.append(this.template(this.model.toJSON()));
        return this;
    }
});

var FooListView = Backbone.View.extend({
    template: _.template($('#foo-list-template').html()),
    initialize: function() {
        this.listenTo(this.collection, 'add', this.renderFooView);
        this.listenTo(this.collection, 'reset', this.render);
    },
    events:{
        'click .add-foo' : 'addFoo'
    },
    addFoo: function() {
        var newFoo = new Foo({
            hobby : $('.foo-name', this.$el).val()
        });  
        this.collection.add(newFoo);
    },
    renderFooView: function(foo) {
        var fooView = new FooView({
            model : foo
        });
        $('.foo-list', this.$el).append(fooView.el);
        fooView.render();
    },
    render: function() {
        var thisView = this;
        this.$el.empty();
        this.$el.append(this.template);
        _.each(this.collection.models, function(foo) {
             thisView.renderFooView(foo); 
        });
        return this;
    }
});

// Bar View
var BarView = Backbone.View.extend({
    className: 'bar',
    template: _.template($('#bar-template').html()),
    renderFooListView: function() {
        var fooListView = new FooListView({
            el: $('.foo-container', this.$el),
            collection : this.model.foos
        });
        fooListView.render();
    },
    render: function() {
        this.$el.append(this.template(this.model.toJSON()));
        this.renderFooListView();
        return this;
    }
});
// Bar List View
var BarListView = Backbone.View.extend({
    template: _.template($('#bar-list-template').html()),
    initialize: function() {
        // Events on collection which will trigger the methods
        this.listenTo(this.collection, 'add', this.renderBarView);
        this.listenTo(this.collection, 'reset', this.render);
    },
    events: {
        'click .add-bar' : 'addBar'
    },
    // Add a new Bar
    addBar: function() {
        var newBar = new Bar({
            name : $('.bar-name', this.$el).val(),
            age : $('.bar-age', this.$el).val()
        });  
        this.collection.add(newBar);
    },
    // Render BarView for each Model in Bars Collection
    renderBarView: function(bar) {
        var barView = new BarView({
            model : bar
        });
        $('.bar-container').append(barView.el);
        barView.render();
    },
    render: function() {
        var thisView = this;
        this.$el.empty();
        this.$el.append(this.template);
        _.each(this.collection.models, function(bar) {
             thisView.renderBarView(bar); 
        });
        return this;
    }
});
// Main View
// Renders the BarListView 
var MainView = Backbone.View.extend({
    el : $('.main'),
    renderBarListView: function() {
        var barListView = new BarListView({
            collection : this.collection
        });
        this.$el.append(barListView.el);
        barListView.render();
    },
    render: function() {
        this.$el.empty();
        this.renderBarListView();
        return this;
    }
});

// Initial obj
var obj = [{ 
    "name" : "Brad", 
    "age": 15,
    "hobbies" : [{"hobby":"play"}, {"hobby": "eat"}]
},{
    "name" : "Micheal", 
    "age": 22,
    "hobbies" : [{"hobby":"sit"}, {"hobby": "walk"}]
}];

// Bars collection and rendering of Main view
var bars = new Bars(obj, {parse : true});
var mainView = new MainView({
    collection : bars
});
mainView.render();

Check Fiddle

Cholinesterase

This is a very nice answer Sushanth, I started a bounty to reward your work. – Sihun

@Sihun .. Thanks :) . I started working with backbone recently and I know it can be too overwhelming when you start on it initially. So I posted a lengthy sol so that it can help out someone. – Cholinesterase