Models examples

anatomy-backbone-models.js

// Our Appointment model doesn't seem too useful yet. Add two default attributes, 
// title as the string "Checkup", and date which should default to the current time new Date()
var Appointment = Backbone.Model.extend({
  defaults: {
    title: "Checkup",
    date: new Date()
  }
  });

//While messing around in the console, you've discovered a strange bug. Every new Appointment you create has the same exact date, instead of the date and time of when the Appointment instance was created.
//This is because new Date() is evaluated once, when the Appointment model is first created, and not re-evaluated every time a new instance is created.
//To fix this you'll want to assign a function to defaults instead of just a plain object. Wrap the object below in a function which returns the object. This will cause the defaults to get evaluated every time a new instance is created.
var Appointment = Backbone.Model.extend({
  defaults: function() {
    return {
    title: 'Checkup',
    date: new Date()
    }
  }
});

// Dr. Goodparts finally ponied up for a server and has seeded it with his first few appointments. 
// Luckily for us, he bought the REST package with the JSON add-on.
// Point the root URL of your Appointment model to the /appointments endpoint.
// Then, create a new Appointment with an id of 1, and fetch its data from the server.

var Appointment = Backbone.Model.extend({urlRoot: '/appointments'});
var appointment = new Appointment({id: 1})
appointment.fetch();


// Setting the urlRoot of the Appointment model lets us do more than just fetch from the server, 
// it also lets us sync changes made to model instances.
// Dr. Goodparts isn't feeling good today so we're going to have to cancel his appointments. Set the appointment's 
// cancelled attribute to true and save the appointment to the server

var appointment = new Appointment({id: 1});
appointment.set({cancelled: true});
appointment.save();

// Dr. Goodparts is upset that he wasn't notified when we changed his last appointment to cancelled.
// Add a listener to the appointment model instance to pop-up an alert box (using alert) whenever any of the model 
// attributes change.

var appointment = new Appointment({id: 1});
appointment.on('change', function(){
  alert("Hey Dr. Goodparts, your appointment has changed!");
});


// Dr. Goodparts browser crashed because of too many alerts.
// Instead of listening for all attribute changes, just listen and alert when changes are made to the cancelled attribute.

appointment.on('change:cancelled', function(){
  alert("Hey Dr. Goodparts, your appointment has changed!");
});

// We've already seen how we can use get to access attributes on a model instance, but what if we wanted them all at once?
// Use the console.log function to log the JSON of the appointment instance. 
// If you don't remember what function to call, consult the Backbone Model docs.

var appointment = new Appointment({id: 1});
console.log(appointment.toJSON());