While our first application gave us a good taste of how Backbone.js applications are made, most real-world applications will want to communicate with a back-end of some sort. Let's reinforce what we have already learned with another example, but this time we will also create a RESTful API for our application to talk to.
In this exercise we will build a library application for managing digital books using Backbone. For each book we will store the title, author, date of release and some keywords. We'll also show a picture of the cover.
##Setting up
First we need to create a folder structure for our project. To keep the front- and back-end seperate, we will create a folder called site in the project root. Within here we can create the directories css, img and js.
As with the last example we will split our JavaScript files by their function, so under the js directory create new folders lib, models, collections and views.
Download the Backbone, Underscore and jQuery libraries and copy them to your js/lib folder. We need a placeholder image for the book covers. Save this image to your site/img folder:
Just like before we need to load all of our dependencies in the site/index.html file
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8"/>
<title>Backbone.js Library</title>
<link rel="stylesheet" href="css/screen.css">
</head>
<body>
<script src="js/lib/jquery.min.js"></script>
<script src="js/lib/underscore-min.js"></script>
<script src="js/lib/backbone-min.js"></script>
<script src="js/models/book.js"></script>
<script src="js/collections/library.js"></script>
<script src="js/views/book.js"></script>
<script src="js/views/library.js"></script>
<script src="js/app.js"></script>
</body>
</html>We should also add in the HTML for the user interface. We'll want a form for adding a new book
<div id="books">
<form id="addBook" action="#">
<div>
<label for="coverImage">CoverImage: </label><input id="coverImage" type="file" />
<label for="title">Title: </label><input id="title" type="text" />
<label for="author">Author: </label><input id="author" type="text" />
<label for="releaseDate">Release date: </label><input id="releaseDate" type="text" />
<label for="keywords">Keywords: </label><input id="keywords" type="text" />
<button id="add">Add</button>
</div>
</form>
</div>and a template for displaying each book
<script id="bookTemplate" type="text/template">
<img src="<%= coverImage %>"/>
<ul>
<li><%= title %></li>
<li><%= author %></li>
<li><%= releaseDate %></li>
<li><%= keywords %></li>
</ul>
<button class="delete">Delete</button>
</script>To see what this will look like with some data in it, go ahead and add a manually filled in book to the books div.
<div class="bookContainer">
<img src="img/placeholder.png"/>
<ul>
<li>Title</li>
<li>Author</li>
<li>Release Date</li>
<li>Keywords</li>
</ul>
<button class="delete">Delete</button>
</div>Open this file in a browser and it should look something like this:
Not so great. This is not a CSS tutorial, but we still need to do some formatting. Create a file screen.css in your site/css folder
body {
background-color: #eee;
}
.bookContainer {
outline: 1px solid #aaa;
width: 350px;
height: 130px;
background-color: #fff;
float: left;
margin: 5px;
}
.bookContainer img {
float: left;
margin: 10px;
}
.bookContainer ul {
list-style-type: none;
margin-bottom: 0;
}
.bookContainer button {
float: right;
margin: 10px;
}
#addBook label {
width: 100px;
margin-right: 10px;
text-align: right;
line-height: 25px;
}
#addBook label, #addBook input {
display: block;
margin-bottom: 10px;
float: left;
}
#addBook label[for="title"], #addBook label[for="releaseDate"] {
clear: both;
}
#addBook button {
display: block;
margin: 5px 20px 10px 10px;
float: right;
clear: both;
}
#addBook div {
width: 550px;
}
#addBook div:after {
content: "";
display: block;
height: 0;
visibility: hidden;
clear: both;
font-size: 0;
line-height: 0;
}Now it looks a bit better:
So this is what we want the final result to look like, but with more books. Go ahead and copy the bookContainer div a few more times if you would like to see what it looks like. Now we are ready to start developing the actual application.
// site/js/models/book.js
var app = app || {};
app.Book = Backbone.Model.extend({
defaults: {
coverImage: 'img/placeholder.png',
title: 'No title',
author: 'Unknown',
releaseDate: 'Unknown',
keywords: 'None'
}
});// site/js/collections/library.js
var app = app || {};
app.Library = Backbone.Collection.extend({
model: app.Book
});This is our model of a book and collection to hold the list. These are both very simple, with the model only declaring some defaults. In order to display books we need a view.
// site/js/views/book.js
var app = app || {};
app.BookView = Backbone.View.extend({
tagName: 'div',
className: 'bookContainer',
template: $( '#bookTemplate' ).html(),
render: function() {
//tmpl is a function that takes a JSON object and returns html
var tmpl = _.template( this.template );
//this.el is what we defined in tagName. use $el to get access to jQuery html() function
this.$el.html( tmpl( this.model.toJSON() ) );
return this;
}
});We'll also need a view for the list itself.
// site/js/views/library.js
var app = app || {};
app.LibraryView = Backbone.View.extend({
el: $( '#books' ),
initialize: function( initialBooks ) {
this.collection = new app.Library( initialBooks );
this.render();
},
render: function() {
_.each( this.collection.models, function( item ) {
this.renderBook( item );
}, this );
},
renderBook: function( item ) {
var bookView = new app.BookView({
model: item
});
this.$el.append( bookView.render().el );
}
});Note that in the initialize function we accept an array of data that we pass to the app.Library constructor. We'll use this to populate our collection with some sample data so that we can see everything is working correctly. We wrap up with the entry point to our code, with the sample data.
// site/js/app.js
var app = app || {};
$(function() {
var books = [
{ title: 'JavaScript: The Good Parts', author: 'Douglas Crockford', releaseDate: '2008', keywords: 'JavaScript Programming' },
{ title: 'The Little Book on CoffeeScript', author: 'Alex MacCaw', releaseDate: '2012', keywords: 'CoffeeScript Programming' },
{ title: 'Scala for the Impatient', author: 'Cay S. Horstmann', releaseDate: '2012', keywords: 'Scala Programming' },
{ title: 'American Psycho', author: 'Bret Easton Ellis', releaseDate: '1991', keywords: 'Novel Splatter' },
{ title: 'Eloquent JavaScript', author: 'Marijn Haverbeke', releaseDate: '2011', keywords: 'JavaScript Programming' }
];
new app.LibraryView( books );
});If you view index.html in a browser you should see something like this:
This is a complete Backbone application, though it doesn't yet do anything interesting.
##Wiring in the interface
Now we'll add some functionality to the useless form at the top and the delete buttons on each book.
###Adding models
When the user clicks the add button we want to take the data in the form and use it to create a new model. In the LibraryView we need to add an event handler for the click event.
events:{
'click #add':'addBook'
},
addBook: function( e ) {
e.preventDefault();
var formData = {};
$( '#addBook div' ).children( 'input' ).each( function( i, el ) {
if( $( el ).val() != '' )
{
formData[ el.id ] = $( el ).val();
}
});
this.collection.add( new app.Book( formData ) );
},We select all the input elements of the form that have a value and iterate over them using jQuery's each. Since we used the same names for ids in our form as the keys on our Book model we can simply store them directly in the formData object. We then create a new Book from the data and add it to the collection. We skip fields without a value so that the defaults will be applied.
By default, Backbone will send an event object as parameter to the function. This is useful for us in this case since we dont want the form to actually submit and reload the page. Adding a preventDefault to the addBook function sorts this out for us.
Now we just need to make the view render again when a new model is added. We put
this.collection.on( 'add', this.renderBook, this );in the initialize function of LibraryView.
Now you should be ready to take the application for a spin.
You may notice that the file input for the cover image isn’t working, but that is left as an exercise to the reader.
###Removing models
Now we need to wire up the delete button. Set up the event handler in the BookView
events: {
'click .delete': 'deleteBook'
},
deleteBook: function() {
//Delete model
this.model.destroy();
//Delete view
this.remove();
},You should now be able to add and remove books from the library.
##Creating the back-end
Now we need to make a small detour and set up a server with a REST api. Since this is a JavaScript book we will use JavaScript to create the server using node.js. If you are more comfortable in setting up a REST server in another language, this is the API you need to conform to:
url HTTP Method Operation
/api/books GET Get an array of all books
/api/books/:id GET Get the book with id of :id
/api/books POST Add a new book and return the book with an id attribute added
/api/books/:id PUT Update the book with id of :id
/api/books/:id DELETE Delete the book with id of :id
The outline for this section looks like this:
- Install node.js, npm and MongoDB
- Install node modules
- Create a simple web server
- Connect to the database
- Create the REST API
###Install node.js, npm and MongoDB
Download and install node.js from nodejs.org. The node package manager (npm) will be installed as well.
Download and install MongoDB from mongodb.org. There are detailed installation guides on the website
###Install node modules
Create a file called package.json in the root of your project. It should look like
{
"name": "backbone-library",
"version": "0.0.1",
"description": "A simple library application using the Backbone framework",
"dependencies": {
"express": "~3.1.0",
"path": "~0.4.9",
"mongoose": "~3.5.5"
}
}Amongst other things, this file tells npm what the dependencies are for our project. On the command line, from the root of your project, type:
npm installYou should see npm fetch the dependencies that we listed in our package.json and save them within a folder called node_modules.
Your folder structure should look something like this:
node_modules/
.bin/
express/
mongoose/
path/
site/
css/
img/
js/
index.html
server.js
package.json
###Create a simple web server
Open server.js and enter the following:
// Module dependencies.
var application_root = __dirname,
express = require( 'express' ), //Web framework
path = require( 'path' ), //Utilities for dealing with file paths
mongoose = require( 'mongoose' ); //MongoDB integration
//Create server
var app = express();
// Configure server
app.configure( function() {
//parses request body and populates request.body
app.use( express.bodyParser() );
//checks request.body for HTTP method overrides
app.use( express.methodOverride() );
//perform route lookup based on url and HTTP method
app.use( app.router );
//Where to serve static content
app.use( express.static( path.join( application_root, 'site') ) );
//Show all errors in development
app.use( express.errorHandler({ dumpExceptions: true, showStack: true }));
});
//Start server
var port = 4711;
app.listen( port, function() {
console.log( 'Express server listening on port %d in %s mode', port, app.settings.env );
});We start off by loading the modules required for this project: Express for creating the HTTP server, Path for dealing with file paths and mongoose for connecting with the database. We then create an express server and configure it using an anonymous function. This is a pretty standard configuration and for our application we don’t actually need the methodOverride part. It is used for issuing PUT and DELETE HTTP requests directly from a form, since forms normally only support GET and POST. Finally I start the server by running the listen function. The port number used, in this case 4711, could be any free port on your system. I simply used 4711 since it is unlikely to have been used by anything else. We are now ready to run our first server:
node server.jsIf you open a browser on http://localhost:4711 you should see something like this:
This is where we left off in Part 2, but we are now running on a server instead of directly from the files. Great job! We can now start defining routes (URLs) that the server should react to. This will be our REST API. Routes are defined by using app followed by one of the HTTP verbs get, put, post and delete, which corresponds to Create, Read, Update and Delete. Let us go back to server.js and define a simple route:
// Routes
app.get( '/api', function( request, response ) {
response.send( 'Library API is running' );
});The get function takes a URL as first parameter and a function as second. The function will be called with request and response objects. Now you can restart node and go to our specified URL:
###Connect to database
Fantastic. Now since we want to store our data in MongoDB we need to define a schema. Add this to server.js:
//Connect to database
mongoose.connect( 'mongodb://localhost/library_database' );
//Schemas
var Book = new mongoose.Schema({
title: String,
author: String,
releaseDate: Date
});
//Models
var BookModel = mongoose.model( 'Book', Book );As you can see, schema definitions are quite straight forward. They can be more advanced, but this will do for us. I also extracted a model (BookModel) from Mongo. This is what we will be working with. Next up we define a GET operation for the REST API that will return all books:
//Get a list of all books
app.get( '/api/books', function( request, response ) {
return BookModel.find( function( err, books ) {
if( !err ) {
return response.send( books );
} else {
return console.log( err );
}
});
});The find function of Model is defined like this: function find (conditions, fields, options, callback) – but since we want a function that returns all books we only need the callback parameter. The callback will be called with an error object and an array of found objects. If there was no error we return the array of objects to the client using the send function of the result object, otherwise we log the error to the console.
To test our API we need to do a little typing in a JavaScript console. Restart node and go to localhost:4711 in your browser. Open up the JavaScript console. If you are using Google Chrome, go to View->Developer->JavaScript Console. If you are using Firefox, install Firebug and go to View->Firebug. Most other browsers will have a similar console. In the console type the following:
jQuery.get( '/api/books/', function( data, textStatus, jqXHR ) {
console.log( 'Get response:' );
console.dir( data );
console.log( textStatus );
console.dir( jqXHR );
});…and press enter and you should get something like this:
Here I used jQuery to make the call to our REST API, since it was already loaded on the page. The returned array is obviously empty, since we have not put anything into the database yet. Lets go and create a POST route that enables adding new items in server.js:
//Insert a new book
app.post( '/api/books', function( request, response ) {
var book = new BookModel({
title: request.body.title,
author: request.body.author,
releaseDate: request.body.releaseDate
});
book.save( function( err ) {
if( !err ) {
return console.log( 'created' );
} else {
return console.log( err );
}
});
return response.send( book );
});We start by creating a new BookModel passing an object with title, author and releaseDate attributes. The data are collected from request.body. This means that anyone calling this operation in the API needs to supply a JSON object containing the title, author and releaseDate attributes. Actually, the caller can omit any or all attributes since we have not made any of them mandatory.
We then call the save function on the BookModel passing in a callback in the same way as with the previous get route. Finally we return the saved BookModel. The reason we return the BookModel and not just “success” or similar string is that when the BookModel is saved it will get an _id attribute from MongoDB, which the client needs when updating or deleting a specific book. Lets try it out again, restart node and go back to the console and type:
jQuery.post( '/api/books', {
'title': 'JavaScript the good parts',
'author': 'Douglas Crockford',
'releaseDate': new Date( 2008, 4, 1 ).getTime()
}, function(data, textStatus, jqXHR) {
console.log( 'Post response:' );
console.dir( data );
console.log( textStatus );
console.dir( jqXHR );
});..and then
jQuery.get( '/api/books/', function( data, textStatus, jqXHR ) {
console.log( 'Get response:' );
console.dir( data );
console.log( textStatus );
console.dir( jqXHR );
});You should now get an array of size 1 back from our server. You may wonder about this line:
'releaseDate': new Date(2008, 4, 1).getTime()MongoDB expects dates in UNIX time format (milliseconds from the start of Jan 1st 1970 UTC), so we have to convert dates before posting. The object we get back however, contains a JavaScript Date object. Also note the _id attribute of the returned object.
Lets move on to creating a GET request that retrieves a single book in server.js:
//Get a single book by id
app.get( '/api/books/:id', function( request, response ) {
return BookModel.findById( request.params.id, function( err, book ) {
if( !err ) {
return response.send( book );
} else {
return console.log( err );
}
});
});Here we use colon notation (:id) to tell express that this part of the route is dynamic. We also use the findById function on BookModel to get a single result. Now you can get a single book by adding its id to the URL like this:
jQuery.get( '/api/books/4f95a8cb1baa9b8a1b000006', function( data, textStatus, jqXHR ) {
console.log( 'Get response:' );
console.dir( data );
console.log( textStatus );
console.dir( jqXHR );
});Lets create the PUT (update) function next:
//Update a book
app.put( '/api/books/:id', function( request, response ) {
console.log( 'Updating book ' + request.body.title );
return BookModel.findById( request.params.id, function( err, book ) {
book.title = request.body.title;
book.author = request.body.author;
book.releaseDate = request.body.releaseDate;
return book.save( function( err ) {
if( !err ) {
console.log( 'book updated' );
} else {
console.log( err );
}
return response.send( book );
});
});
});This is a little larger than previous ones, but should be pretty straight forward – we find a book by id, update its properties, save it and send it back to the client.
To test this we need to use the more general jQuery ajax function. In these examples you will need to replace the id property with one that matches an item in your own database:
jQuery.ajax({
url: '/api/books/4f95a8cb1baa9b8a1b000006',
type: 'PUT',
data: {
'title': 'JavaScript The good parts',
'author': 'The Legendary Douglas Crockford',
'releaseDate': new Date( 2008, 4, 1 ).getTime()
},
success: function( data, textStatus, jqXHR ) {
console.log( 'Post response:' );
console.dir( data );
console.log( textStatus );
console.dir( jqXHR );
}
});Finally we create the delete route:
//Delete a book
app.delete( '/api/books/:id', function( request, response ) {
console.log( 'Deleting book with id: ' + request.params.id );
return BookModel.findById( request.params.id, function( err, book ) {
return book.remove( function( err ) {
if( !err ) {
console.log( 'Book removed' );
return response.send( '' );
} else {
console.log( err );
}
});
});
});…and try it out:
jQuery.ajax({
url: '/api/books/4f95a5251baa9b8a1b000001',
type: 'DELETE',
success: function( data, textStatus, jqXHR ) {
console.log( 'Post response:' );
console.dir( data );
console.log( textStatus );
console.dir( jqXHR );
}
});So now our REST API is complete – we have support for all HTTP verbs. What next? Well, until now I have left out the keywords part of our books. This is a bit more complicated since a book could have several keywords and we don’t want to represent them as a string, but rather an array of strings. To do that we need another schema. Add a Keywords schema right above our Book schema:
//Schemas
var Keywords = new mongoose.Schema({
keyword: String
});To add a sub schema to an existing schema we use brackets notation like so:
var Book = new mongoose.Schema({
title: String,
author: String,
releaseDate: Date,
keywords: [ Keywords ]
});Also update POST and PUT
//Insert a new book
app.post( '/api/books', function( request, response ) {
var book = new BookModel({
title: request.body.title,
author: request.body.author,
releaseDate: request.body.releaseDate,
keywords: request.body.keywords
});
book.save( function( err ) {
if( !err ) {
return console.log( 'created' );
} else {
return console.log( err );
}
});
return response.send( book );
});
//Update a book
app.put( '/api/books/:id', function( request, response ) {
console.log( 'Updating book ' + request.body.title );
return BookModel.findById( request.params.id, function( err, book ) {
book.title = request.body.title;
book.author = request.body.author;
book.releaseDate = request.body.releaseDate;
book.keywords = request.body.keywords;
return book.save( function( err ) {
if( !err ) {
console.log( 'book updated' );
} else {
console.log( err );
}
return response.send( book );
});
});
});There we are, that should be all we need, now we can try it out in the console:
jQuery.post( '/api/books', {
'title': 'Secrets of the JavaScript Ninja',
'author': 'John Resig',
'releaseDate': new Date( 2008, 3, 12 ).getTime(),
'keywords':[
{ 'keyword': 'JavaScript' },
{ 'keyword': 'Reference' }
]
}, function( data, textStatus, jqXHR ) {
console.log( 'Post response:' );
console.dir( data );
console.log( textStatus );
console.dir( jqXHR );
});You should now have a fully functional REST server. We can now hook into this from our front-end.
##Talking to the server
In this part we will cover connecting our Backbone application to the server through the REST API.
As we mentioned in chapter 3 we can retrieve models from a server using collection.fetch() if we set collection.url to be the URL of the API end-point. Let's update the Library collection to do that now
var app = app || {};
app.Library = Backbone.Collection.extend({
model: app.Book,
url: '/api/books'
});The default implementation of Backbone.sync will assume that the API looks like this:
url HTTP Method Operation
/api/books GET Get an array of all books
/api/books/:id GET Get the book with id of :id
/api/books POST Add a new book and return the book with an id attribute added
/api/books/:id PUT Update the book with id of :id
/api/books/:id DELETE Delete the book with id of :id
To make our application get the Book models from the server on page load we need to update the LibraryView. It is recommended in the Backbone documentation to insert all models when the page is generated on the server side, rather than fetching them from the client side once the page is loaded. Since this chapter is trying to give you a more complete picture of how to communicate with a server, we will go ahead and ignore that recommendation. Go to the LibraryView declaration and update the initialize function as follows:
initialize: function() {
this.collection = new app.Library();
this.collection.fetch();
this.render();
this.collection.on( 'add', this.renderBook, this );
this.collection.on( 'reset', this.render, this );
},The initialize function no longer takes a set of sample data as an argument, so doesn't pass anything to the app.Library constructor. You can now remove the sample data from site/js/app.js. Instead we will populate our Library from the database with this.collection.fetch(). I have also added a listener on the reset event. We need to do this since the fetching of models is asynchronous and happens after the page is rendered. When the fetching is finished, Backbone will fire the reset event, which we listen to and re-render the view. If you reload the page now you should see all books that are stored on the server:
As you can see the date and keywords look a bit weird. The date delivered from the server is converted into a JavaScript Date object and when applied to the underscore template it will use the toString() function to display it. There isn’t very good support for formatting dates in JavaScript so we will use the dateFormat jQuery plugin to fix this. Go ahead and download it from here and put it in your site/js/lib folder. Update the book template so that the date is displayed with:
<li><%= $.format.date( new Date( releaseDate ), 'MMMM yyyy' ) %></li>and add a script element for the plugin
<script src="js/lib/jquery-dateFormat-1.0.js"></script>Now the date on the page should look a bit better. How about the keywords? Since we are receiving the keywords in an array we need to execute some code that generates a string of separated keywords. To do that we can omit the equals character in the template tag which will let us execute code that doesn’t display anything:
<li><% _.each( keywords, function( keyobj ) {%> <%= keyobj.keyword %><% } ); %></li>Here I iterate over the keywords array using the each function and print out every single keyword. Note that I display the keyword using the <%= tag. This will display the keywords with a space between.
Reloading the page again should look quite decent:
Now go ahead and delete a book and then reload the page: Tadaa! the deleted book is back! Not cool, why is this? This happens because when we get the BookModels from the server they have an _id attribute (notice the underscore), but Backbone expects an id attribute (no underscore). Since no id attribute is present, Backbone sees this model as new and deleting a new model doesn’t need any synchronization.
To fix this we could use the parse function of Backbone.Model. The parse function lets you edit the server response before it is passed to the Model constructor. Add a parse method to the Book model:
parse: function( response ) {
response.id = response._id;
return response;
}Simply copy the value of _id to the needed id attribute. If you reload the page you will see that models are actually deleted on the server when you press the delete button.
Another, simpler way of making Backbone recognize _id as its unique identifier is to set the idAttribute of the model to _id.
If you now try to add a new book using the form you’ll notice that it is a similar story to delete – models wont get persisted on the server. This is because Backbone.Collection.add doesn’t automatically sync, but it is easy to fix. In LibraryView in app.js, change the line reading:
this.collection.add( new Book( formData ) );…to:
this.collection.create( formData );Now newly created books will get persisted. Actually, they probably wont if you enter a date. The server expects a date in UNIX timestamp format (milliseconds since Jan 1, 1970). Also any keywords you enter wont be stored since the server expects an array of objects with the attribute ‘keyword’.
We start with fixing the date issue. We don’t really want the users to enter a date into a specific format manually so we’ll use the standard datepicker from jQuery UI. Go ahead and create a custom jQuery UI download containing datepicker from here. Add the css theme to site/css/ and the JavaScript to site/js/lib. Link to them in index.html:
<link rel="stylesheet" href="css/cupertino/jquery-ui-1.8.19.custom.css">"cupertino" is the name of the style I chose when downloading jQuery UI.
The JavaScript file must be loaded after jQuery.
<script src="js/lib/jquery.min.js"></script>
<script src="js/lib/jquery-ui-1.10.0.custom.min.js"></script>Now in app.js, bind a datepicker to our releaseDate field:
var app = app || {};
$(function() {
$( '#releaseDate' ).datepicker();
new app.LibraryView();
});You should now be able to pick a date when clicking in the releaseDate field:
Finally, we have to make sure that the form input is properly transformed into our storage format. Change the addBook function in LibraryView to:
addBook: function( e ) {
e.preventDefault();
var formData = {};
$( '#addBook div' ).children( 'input' ).each( function( i, el ) {
if( $( el ).val() != '' )
{
if( el.id === 'keywords' ) {
formData[ el.id ] = [];
_.each( $( el ).val().split( ' ' ), function( keyword ) {
formData[ el.id ].push({ 'keyword': keyword });
});
} else if( el.id === 'releaseDate' ) {
formData[ el.id ] = $( '#releaseDate' ).datepicker( 'getDate' ).getTime();
} else {
formData[ el.id ] = $( el ).val();
}
}
});
this.collection.create( formData );
},Here I check if the current element is the releaseDate input field, in which case I use datePicker(“getDate”) which will give me a Date object and then use the getTime function on that to get the time in milliseconds. Then I check if the current element is the keywords input field, in which case I split the string on each space and create an array with keyword objects. Now you should be able to add new books with both release date and keywords!
In a real world scenario, the model and the view can be adapted to connect a third party API. For example:
url HTTP Method Operation
index.php?option=com_todo&view=books&task=get GET Get an array of all books
In the model, you can define the third party API URL via url definition.
url : function() {
return 'index.php?option=com_todo&view=books&task=get';
}In the view, you can define the attributes to be processed by the model.
// Third party API example.
this.collection.create( this.collection.model, {
attrs: {
bookId: this.$( '#book_id' ).val()
},
// Wait for the answer.
wait: true,
// Report if there's any error.
error: function( model, fail, xhr ) {
....
}
});The final result is a POST to the defined url. In the POST body, the attributes are submitted as a JSON encoded array.
$raw = file_get_contents('php://input');
$data = json_decode($raw, true);
$book_id = $data['bookId'];In this chapter we made our application persistent by binding it to a server using a REST API. We also looked at some problems that might occur when serializing and deserializing data and their solutions. We looked at the dateFormat and the datepicker jQuery plugins and how to do some more advanced things in our Underscore templates. The code is available here.