Model validation in Backbone.js

Todo.js

var Todo = Backbone.Model.extend({
 
    url: '/todo',
 
    defaults: {
        'itemtext' : '',
        'priority': ''
    },
 
    validate: function (attrs) {
        var errors = [];
 
        if (!attrs.itemtext) {
            errors.push({name: 'itemtext', message: 'Todo item can not be empty..'});
        }
 
        return errors.length > 0 ? errors : false;
    }
 
});