Validating the data

In Backbone, validation is taken care of by the model.validate() method. By default, the Backbone.Model class doesn't have a validate() method on its own. However, the developers are encouraged to add a validate() method that gets called by the model every time an attribute is saved or set with validate: true passed. A copy of the attributes is sent to the validate() method with all the changed values. Let's look at a simple data validation:

var User = Backbone.Model.extend({
  validation: {    emailRegEx: /^\s*[\w\-\+_]+(\.[\w\-\+_]+)*\@[\w\-\+_]+\.[\w\-\+_]+(\.[\w\-\+_]+)*\s*$/
},

  defaults: {
    name: '',
    email: ''
  },

  validate: function (attr) {
    if (attr.name.length === 0) {
      return 'Name is required';
    }

    if (attr.email.length === 0) {
      return 'Email is required';
    }

    if (!this.validation.emailRegEx.test(attr.email)) {
      return 'Please provide a valid email';
    }
  }
});

// Define the user view
var UserView = Backbone...