Question

I have a parent view ProductListView containing multiple child views ProductView in a multi-step wizard. When a user click on a ProductView, its model’s id should be stored somewhere (possibly in an array) so that it can be sent back to the server side for processing.

Problem: Where should I store the id of the ProductView that has been clicked by the user? I tried storing it in its parent view ProductListView but cannot seem to access the array selectedProducts in the parent view from the child view ProductView.

Is this the correct approach? How should this be done?

Model

ProductCollection = Backbone.Collection.extend({
    model: Product,
    url: '/wizard'
});

Parent View

ProductListView = Backbone.View.extend({
    el: '#photo_list',

    selectedProducts: {},  // STORING SELECTED PRODUCTS IN THIS ARRAY

    initialize: function() {
        this.collection.bind('reset', this.render, this);
    },

    render: function() {
        this.collection.each(function(product, index){
            $(this.el).append(new ProductView({ model: product }).render().el);
        }, this);
        return this;
    }
});

Child View

ProductView = Backbone.View.extend({
    tagname: 'div',
    className: 'photo_box',

    events: {
        'click': 'toggleSelection'
    },

    template: _.template($('#tpl-PhotoListItemView').html()),

    render: function() {
        this.$el.html(this.template( this.model.toJSON() ));
        return this;
    },

    // ADDS ITS MODEL'S ID TO ARRAY
    toggleSelection: function() {
        this.parent.selectedProducts.push(this.model.id);
        console.log(this.parent.selectedProducts);
    }
});

Answer 1

I don’t think parent is a property of a backbone View type, and you haven’t defined it, so there’s no way this line is going to work:

this.parent.selectedProducts.push(this.model.id);

It seems like the correct approach would be to add a selected property to the Product model; toggle that property in the click handler. Then, when it’s time to submit to the server, collect the IDs by filtering the Products collection for selected items (underscore.js included with Backbone makes this easy).