How to create DOM-dependent element in Backbone Marionette?

Question

In my backbone+marionette application I have used morris.js Line Chart. This chart takes an array of data from the model. And must be created after DOM creating (DOM dependent).

Сode to create the chart:

_createChartData: function () {
    var trends = this.model.get("trends"),
        chartData = [];

    $.each(trends, function (x, y) {
        // some actions with data
    });

    return chartData;
},
_createChart: function () {      
    Morris.Line({
        element: 'promo-chart',
        data: this._createChartData(),
        xkey: 'date',
        ykeys: ['y', 'g'],
    });
}

View and Controller:

define(['utils/hbs', 'modules/model/promo-mdl'], function( Hbs, Promo){
    var PromoView = Marionette.ItemView.extend({
        initialize: function () {
            this._events();
        },

        template: Hbs.tf('modules/promo'),

        templateHelpers: {
            // handlebars helpers
        },

        events: {
            'click #submitBtn'          : '_savePromo',
        },

        _events: function () {
            this.listenTo(this.model, 'change', this.render);
        },

        _savePromo: function () {
            // save data
        }        
    });

    return Marionette.Controller.extend({
        initialize: function (config) {
            this.region = config.region;
            this.model = new Promo({});
            this.model.fetch();
            this._events();
        },

        _events: function () {
            App.vent.on('show:promo', this._show, this);
        },

        _show: function () {
            this.view = new PromoView({ model: this.model });
            this.region.show(this.view);
        }
    });
});

I tried to create this chart in View, but got an errors - empty data or no chart element in DOM. Where to create this chart, in View or Controller? And which event to use? initialize, onShow or onRender?

David Sulc David Sulc · Accepted Answer · 2013-11-01T12:31:58

It seems like you're creating the chart when the element it uses isn't in the DOM yet. Try creating the chart in the view's onShow function:

var PromoView = Marionette.ItemView.extend({

    // code...

    onShow: function(){
      // create chart here
    }
});

How to create DOM-dependent element in Backbone Marionette?

2 Answers