Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Save more on your purchases! discount-offer-chevron-icon
Savings automatically calculated. No voucher code required.
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Newsletter Hub
Free Learning
Arrow right icon
timer SALE ENDS IN
0 Days
:
00 Hours
:
00 Minutes
:
00 Seconds
Knockout.JS Essentials
Knockout.JS Essentials

Knockout.JS Essentials: Implement a successful JavaScript-rich application with KnockoutJS, jQuery, and Bootstrap

eBook
$9.99 $25.99
Paperback
$43.99
Subscription
Free Trial
Renews at $19.99p/m

What do you get with a Packt Subscription?

Free for first 7 days. $19.99 p/m after that. Cancel any time!
Product feature icon Unlimited ad-free access to the largest independent learning library in tech. Access this title and thousands more!
Product feature icon 50+ new titles added per month, including many first-to-market concepts and exclusive early access to books as they are being written.
Product feature icon Innovative learning tools, including AI book assistants, code context explainers, and text-to-speech.
Product feature icon Thousands of reference materials covering every tech concept you need to stay up to date.
Subscribe now
View plans & pricing
Table of content icon View table of contents Preview book icon Preview Book

Knockout.JS Essentials

Chapter 2. KnockoutJS Templates

Once we have built our Catalog, it is time to add a cart to our application. When our code begins to grow, it's necessary to split it in several parts to keep it maintainable. When we split JavaScript code, we are talking about modules, classes, function, libraries, and so on. When we talk about HTML, we call these parts templates.

KnockoutJS has a native template engine that we can use to manage our HTML. It is very simple, but also has a big inconvenience: templates, it should be loaded in the current HTML page. This is not a problem if our app is small, but it could be a problem if our application begins to need more and more templates.

In this chapter, we are going to design our templates with the native engine and then we will speak about mechanisms and external libraries we can use to improve the Knockout template engine.

Preparing the project

We can begin from the project we did in Chapter 1, Refreshing the UI Automatically with KnockoutJS. First of all, we are going to add some style to the page. Add a file called style.css into the css folder. Add a reference in the index.html file, just below the bootstrap reference. The following is the content of the file:

.container-fluid {
  margin-top: 20px;
}
.row {
  margin-bottom: 20px;
}
.cart-unit {
  width: 80px;
}
.btn-xs {
  font-size:8px;
}
.list-group-item {
  overflow: hidden;
}
.list-group-item h4 {
  float:left;
  width: 100px;
}
.list-group-item .input-group-addon {
  padding: 0;
}
.btn-group-vertical > .btn-default {
  border-color: transparent;
}
.form-control[disabled], .form-control[readonly] {
  background-color: transparent !important;
}

Now remove all the content from the body tag except for the script tags and paste in these lines:

<div class="container-fluid">
  <div class="row" id="catalogContainer&quot...

Creating templates

Template elements are commonly declared at the bottom of the body, just above the <script> tags that have references to our external libraries. We are going to define some templates and then we will talk about each one of them:

<!-- templates -->
<script type="text/html" id="header"></script>
<script type="text/html" id="catalog"></script>
<script type="text/html" id="add-to-catalog-modal"></script>
<script type="text/html" id="cart-widget"></script>
<script type="text/html" id="cart-item"></script>
<script type="text/html" id="cart"></script>
<script type="text/html" id="order"></script>
<script type="text/html" id="finish-order-modal"></script>

Each template name is descriptive enough by itself, so it&apos...

Handling templates with if and ifnot bindings

You have learned how to show and hide templates with the power of jQuery and Bootstrap. This is quite good because you can use this technique with any framework you want. The problem with this type of code is that since jQuery is a DOM manipulation library, you need to reference elements to manipulate them. This means you need to know over which element you want to apply the action. Knockout gives us some bindings to hide and show elements depending on the values of our view-model. Let's update the show and hide methods and the templates.

Add both the control variables to your view-model and expose them in the return statement.

var visibleCatalog = ko.observable(true);
var visibleCart = ko.observable(false);

Now update the show and hide methods:

var showCartDetails = function () {
  if (cart().length > 0) {
    visibleCart(true);
  }
};

var hideCartDetails = function () {
  visibleCart(false);
};

var showOrder = function () {
  visibleCatalog...

Managing templates with jQuery

Since we want to load templates from different files, let's move all our templates to a folder called views and make one file per template. Each file will have the same name the template has as an ID. So if the template has the ID, cart-item, the file should be called cart-item.html and will contain the full cart-item template:

<script type="text/html" id="cart-item"></script>
Managing templates with jQuery

The views folder with all templates

Now in the viewmodel.js file, remove the last line (ko.applyBindings(vm)) and add this code:

var templates = [
  'header',
  'catalog',
  'cart',
  'cart-item',
  'cart-widget',
  'order',
  'add-to-catalog-modal',
  'finish-order-modal'
];

var busy = templates.length;
templates.forEach(function(tpl){
  "use strict";
  $.get('views/'+ tpl + '.html').then(function(data){
    $('body').append(data)...

Managing templates with koExternalTemplateEngine

We have seen two ways of loading templates, both of them are good enough to manage a low number of templates, but when lines of code begin to grow, we need something that allows us to forget about template management. We just want to call a template and get the content.

For this purpose, Jim Cowart's library, koExternalTemplateEngine, is perfect. This project was abandoned by the author in 2014, but it is still a good library that we can use when we develop simple projects. In the next chapters, you will learn more about asynchronous loading and module patterns and we will see other libraries that are currently maintained.

We just need to download the library in the js/vendors folder and then link it in our index.html file just below the Knockout library.

<script type="text/javascript" src="js/vendors/knockout.debug.js"></script>
<script type="text/javascript" src="js/vendors/koExternalTemplateEngine_all...

Preparing the project


We can begin from the project we did in Chapter 1, Refreshing the UI Automatically with KnockoutJS. First of all, we are going to add some style to the page. Add a file called style.css into the css folder. Add a reference in the index.html file, just below the bootstrap reference. The following is the content of the file:

.container-fluid {
  margin-top: 20px;
}
.row {
  margin-bottom: 20px;
}
.cart-unit {
  width: 80px;
}
.btn-xs {
  font-size:8px;
}
.list-group-item {
  overflow: hidden;
}
.list-group-item h4 {
  float:left;
  width: 100px;
}
.list-group-item .input-group-addon {
  padding: 0;
}
.btn-group-vertical > .btn-default {
  border-color: transparent;
}
.form-control[disabled], .form-control[readonly] {
  background-color: transparent !important;
}

Now remove all the content from the body tag except for the script tags and paste in these lines:

<div class="container-fluid">
  <div class="row" id="catalogContainer">
    <div class="col-xs-12...
Left arrow icon Right arrow icon

Description

If you are a JavaScript developer who has been using DOM manipulation libraries such as Mootools or Scriptaculous, and you want go further in modern JavaScript development with a simple and well-documented library, then this book is for you. Learning how to use Knockout will be perfect as your next step towards building JavaScript applications that respond to user interaction.

Who is this book for?

If you are a JavaScript developer who has been using DOM manipulation libraries such as Mootools or Scriptaculous, and you want go further in modern JavaScript development with a simple and well-documented library, then this book is for you. Learning how to use Knockout will be perfect as your next step towards building JavaScript applications that respond to user interaction.

What you will learn

  • Organize and maintain your code when applications begin to grow
  • Get to know JavaScript patterns and best practices to keep your code readable
  • Bind JavaScript objects and DOM elements with practical examples
  • Integrate and manage events to give the user a better experience
  • Extend the framework to create your own components
  • Create a singlepage application using the Durandal JavaScript framework
  • Split your application in modules to keep it engrossing and maintainable
  • Manage templates to keep your HTML as simple as possible

Product Details

Country selected
Publication date, Length, Edition, Language, ISBN-13
Publication date : Feb 27, 2015
Length: 232 pages
Edition : 1st
Language : English
ISBN-13 : 9781784397074
Languages :
Tools :

What do you get with a Packt Subscription?

Free for first 7 days. $19.99 p/m after that. Cancel any time!
Product feature icon Unlimited ad-free access to the largest independent learning library in tech. Access this title and thousands more!
Product feature icon 50+ new titles added per month, including many first-to-market concepts and exclusive early access to books as they are being written.
Product feature icon Innovative learning tools, including AI book assistants, code context explainers, and text-to-speech.
Product feature icon Thousands of reference materials covering every tech concept you need to stay up to date.
Subscribe now
View plans & pricing

Product Details

Publication date : Feb 27, 2015
Length: 232 pages
Edition : 1st
Language : English
ISBN-13 : 9781784397074
Languages :
Tools :

Packt Subscriptions

See our plans and pricing
Modal Close icon
$19.99 billed monthly
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Simple pricing, no contract
$199.99 billed annually
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just $5 each
Feature tick icon Exclusive print discounts
$279.99 billed in 18 months
Feature tick icon Unlimited access to Packt's library of 7,000+ practical books and videos
Feature tick icon Constantly refreshed with 50+ new titles a month
Feature tick icon Exclusive Early access to books as they're written
Feature tick icon Solve problems while you work with advanced search and reference features
Feature tick icon Offline reading on the mobile app
Feature tick icon Choose a DRM-free eBook or Video every month to keep
Feature tick icon PLUS own as many other DRM-free eBooks or Videos as you like for just $5 each
Feature tick icon Exclusive print discounts

Frequently bought together


Stars icon
Total $ 131.97
MASTERING KNOCKOUTJS
$54.99
Knockout.JS Essentials
$43.99
KnockoutJS Web Development
$32.99
Total $ 131.97 Stars icon
Banner background image

Table of Contents

9 Chapters
1. Refreshing the UI Automatically with KnockoutJS Chevron down icon Chevron up icon
2. KnockoutJS Templates Chevron down icon Chevron up icon
3. Custom Bindings and Components Chevron down icon Chevron up icon
4. Managing KnockoutJS Events Chevron down icon Chevron up icon
5. Getting Data from the Server Chevron down icon Chevron up icon
6. The Module Pattern – RequireJS Chevron down icon Chevron up icon
7. Durandal – The KnockoutJS Framework Chevron down icon Chevron up icon
8. Developing Web Applications with Durandal – The Cart Project Chevron down icon Chevron up icon
Index Chevron down icon Chevron up icon

Customer reviews

Rating distribution
Full star icon Full star icon Full star icon Full star icon Empty star icon 4
(2 Ratings)
5 star 50%
4 star 0%
3 star 50%
2 star 0%
1 star 0%
Alexander Fyodorov Apr 16, 2016
Full star icon Full star icon Full star icon Full star icon Full star icon 5
Brilliant book. Methodically correct - its main working example is being enhanced part by part during the course of the chapters. I really like the patterns of KO usage summarized here (actually theyare the best patterns to work with javascript anyway). Don't manipulate DOM within the ViewModel, use declarative bindings in the HTML vews. Don't call Ajax from the VMs - use services that can be easily mocked. Use pure models (without presentational details) within VMs. Modularize code with RequireJS, use Durandal framework to facilitate many routine tasks.Highly recommend this book to anyone writing large Single Page Applications.
Amazon Verified review Amazon
Stephen L. Mcconnell Aug 01, 2016
Full star icon Full star icon Full star icon Empty star icon Empty star icon 3
It is a pretty good book. However, there are typos (which one can figure out) and I cannot get a copy of the source files. The examples in the book are confusing (if one has never worked with Knockout JS) and the book often just plops a new function or HTML section without explaining where they go. I beat my head against the wall for half a day before I realized that where the javascript goes is important and the "data-bind" won't work if you put your javascript in the wrong place. I'm new to Javascript and Knockout and am totally frustrated.UPDATE:As I get more into the book and understand more, it becomes less confusing. I have updated this review to three stars. Once I figured out some of the seemingly obfuscated nuances about the writing style and example style, the examples are working better.
Amazon Verified review Amazon
Get free access to Packt library with over 7500+ books and video courses for 7 days!
Start Free Trial

FAQs

What is included in a Packt subscription? Chevron down icon Chevron up icon

A subscription provides you with full access to view all Packt and licnesed content online, this includes exclusive access to Early Access titles. Depending on the tier chosen you can also earn credits and discounts to use for owning content

How can I cancel my subscription? Chevron down icon Chevron up icon

To cancel your subscription with us simply go to the account page - found in the top right of the page or at https://subscription.packtpub.com/my-account/subscription - From here you will see the ‘cancel subscription’ button in the grey box with your subscription information in.

What are credits? Chevron down icon Chevron up icon

Credits can be earned from reading 40 section of any title within the payment cycle - a month starting from the day of subscription payment. You also earn a Credit every month if you subscribe to our annual or 18 month plans. Credits can be used to buy books DRM free, the same way that you would pay for a book. Your credits can be found in the subscription homepage - subscription.packtpub.com - clicking on ‘the my’ library dropdown and selecting ‘credits’.

What happens if an Early Access Course is cancelled? Chevron down icon Chevron up icon

Projects are rarely cancelled, but sometimes it's unavoidable. If an Early Access course is cancelled or excessively delayed, you can exchange your purchase for another course. For further details, please contact us here.

Where can I send feedback about an Early Access title? Chevron down icon Chevron up icon

If you have any feedback about the product you're reading, or Early Access in general, then please fill out a contact form here and we'll make sure the feedback gets to the right team. 

Can I download the code files for Early Access titles? Chevron down icon Chevron up icon

We try to ensure that all books in Early Access have code available to use, download, and fork on GitHub. This helps us be more agile in the development of the book, and helps keep the often changing code base of new versions and new technologies as up to date as possible. Unfortunately, however, there will be rare cases when it is not possible for us to have downloadable code samples available until publication.

When we publish the book, the code files will also be available to download from the Packt website.

How accurate is the publication date? Chevron down icon Chevron up icon

The publication date is as accurate as we can be at any point in the project. Unfortunately, delays can happen. Often those delays are out of our control, such as changes to the technology code base or delays in the tech release. We do our best to give you an accurate estimate of the publication date at any given time, and as more chapters are delivered, the more accurate the delivery date will become.

How will I know when new chapters are ready? Chevron down icon Chevron up icon

We'll let you know every time there has been an update to a course that you've bought in Early Access. You'll get an email to let you know there has been a new chapter, or a change to a previous chapter. The new chapters are automatically added to your account, so you can also check back there any time you're ready and download or read them online.

I am a Packt subscriber, do I get Early Access? Chevron down icon Chevron up icon

Yes, all Early Access content is fully available through your subscription. You will need to have a paid for or active trial subscription in order to access all titles.

How is Early Access delivered? Chevron down icon Chevron up icon

Early Access is currently only available as a PDF or through our online reader. As we make changes or add new chapters, the files in your Packt account will be updated so you can download them again or view them online immediately.

How do I buy Early Access content? Chevron down icon Chevron up icon

Early Access is a way of us getting our content to you quicker, but the method of buying the Early Access course is still the same. Just find the course you want to buy, go through the check-out steps, and you’ll get a confirmation email from us with information and a link to the relevant Early Access courses.

What is Early Access? Chevron down icon Chevron up icon

Keeping up to date with the latest technology is difficult; new versions, new frameworks, new techniques. This feature gives you a head-start to our content, as it's being created. With Early Access you'll receive each chapter as it's written, and get regular updates throughout the product's development, as well as the final course as soon as it's ready.We created Early Access as a means of giving you the information you need, as soon as it's available. As we go through the process of developing a course, 99% of it can be ready but we can't publish until that last 1% falls in to place. Early Access helps to unlock the potential of our content early, to help you start your learning when you need it most. You not only get access to every chapter as it's delivered, edited, and updated, but you'll also get the finalized, DRM-free product to download in any format you want when it's published. As a member of Packt, you'll also be eligible for our exclusive offers, including a free course every day, and discounts on new and popular titles.