Home > Articles > Operating Systems, Server > Microsoft Windows Desktop

This chapter is from the book

Elements of a Windows Store App

As we saw in the previous section, a Windows Store app is built using several technologies. A Windows Store app is built out of a combination of open and familiar web technologies, such as HTML5, JavaScript, and CSS3 and Microsoft technologies such as the Windows Library for JavaScript and the Windows Runtime. Let me say a little more about each of these elements of a Windows Store app.

JavaScript

This book is all about writing Windows Store apps using JavaScript. As an alternative to JavaScript, you also could write Windows Store apps using C#, Visual Basic, or even C++.

When writing Windows Store apps, you can take advantage of the features of ECMAScript 5 which is the latest version of JavaScript. This means that you can use the new JavaScript Array methods such as indexOf() and forEach(). You also can use property setters and getters and the use strict statement.

HTML5

When writing Windows Store apps, you can take advantage of many of the new features of HTML5 and related standards. Here is a list of some of the most important of these new features:

  • Form Validation Attributes—You can take advantage of the new validation attributes in the HTML5 standard to perform form validation. I discuss these new validation attributes and how you can use them in a Windows Store app in Chapter 5, “Creating Forms.”
  • data-*—The data dash star standard enables you to add custom attributes to existing HTML5 elements. The WinJS library uses data-* for declarative data-binding and declarative control instantiation.
  • Indexed Database API (IndexedDB)—The Indexed Database API exposes a database in the browser. If you need to store a list of products in a database within a Windows Store app, then you can take advantage of IndexedDB. I explain how to use IndexedDB in Chapter 9, “Creating Data Sources.”
  • File API—The HTML5 File API enables you work with files in the browser. We used the HTML5 API in the previous section when building our first Windows Store app (the URL.createObjectURL() method).
  • Canvas—Enables you to draw graphics using JavaScript. I provide you with an introduction to Canvas in Chapter 15, “Graphics and Games.”
  • Web Workers—Enables you to execute background tasks without blocking the user interface thread.
  • WebGL—This is new with Windows 8.1. WebGL enables you to build 3D games with JavaScript.

Cascading Style Sheets 3

When you build Windows Store apps, you can take advantage of several new features of the Cascading Style Sheets 3 standard (and related standards) including the following:

  • Media Queries—Enables you to apply different styles depending on the characteristics of a device, such as the height, width, or orientation of the device. I discuss Media Queries in Chapter 11.
  • CSS3 Grid Layout—Enables you to lay out HTML content in columns and rows without using HTML tables.
  • CSS3 Flexible Box Layout (FlexBox)—Enables you to preserve relative element position and size when displaying HTML content in different devices.

Windows Runtime

The Windows Runtime (WinRT) contains a class library that you can use in your Windows Store apps. These classes are projected directly into JavaScript, so they appear to be built-in JavaScript objects.

For example, when we wrote our first Windows Store app, we took advantage of the WinRT Windows.Media.Capture.CameraCaptureUI class. When we called the CameraCaptureUI.captureFileAsync() method, we were able to take a picture.

All of the WinRT classes are exposed in JavaScript from the root Windows namespace. For example, you create an instance of the CameraCaptureUI class with the following code:

var captureUI = new Windows.Media.Capture.CameraCaptureUI ();

The WinRT classes extend JavaScript with all of the functionality that you need when building a Windows application. These classes enable you to do fun and amazing things such as:

  • Geolocation—Use the WinRT Windows.Devices.Geolocation.Geolocator class to get your current latitude and longitude.
  • File Access—Read and write to the file system by taking advantage of the WinRT classes in the Windows.Storage namespace.
  • Compass—Always know the direction of True North with the Windows.Devices.Sensors.Compass class.
  • Print—Print from your Windows Store app by using the Windows.Printing.PrintManager class.
  • Compress Files—Compress and decompress files using the classes in the WinRT Windows.Storage.Compression namespace.

Windows Library for JavaScript

The Windows Library for JavaScript (WinJS) is a pure JavaScript library created by Microsoft specifically for building Windows Store apps. Understanding how to use this library is the primary focus of this book.

The WinJS library contains all of the WinJS controls. These are the controls that you use to build the user interface for your Windows Store app. For example, the WinJS library includes a DatePicker control that displays a user interface widget for selecting a date.

What About jQuery?

jQuery is the most popular JavaScript library in the universe. An obvious question, therefore, is can you use jQuery when building Windows store apps?

The answer is yes. You can use jQuery when building Windows Store apps. Let me show you.

The easiest way to add jQuery to a Windows Store app project is to use the Library Package Manager in Visual Studio. Select the menu option Tools, Library Package Manager, Package Manager Console. Enter the command install-package jQuery into the Package Manager Console window (see Figure 1.14).

FIGURE 1.14

FIGURE 1.14 Adding jQuery with the Library Package Manager Console

Executing the install-package jQuery command adds a Scripts folder with four files: the full version of jQuery, the minified version of jQuery, an IntelliSense file, and a source map. The IntelliSense file enables Visual Studio to provide jQuery intellisense when you use jQuery methods and the source map provides debugging support.

Listing 1.3 contains a combined HTML and JavaScript file that uses jQuery.

LISTING 1.3 Using jQuery in a Windows Store App

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title>jQueryWindows8</title>

    <!-- WinJS references -->
    <link href="//Microsoft.WinJS.2.0/css/ui-dark.css" rel="stylesheet" />
    <script src="//Microsoft.WinJS.2.0/js/base.js"></script>
    <script src="//Microsoft.WinJS.2.0/js/ui.js"></script>

    <!-- jQueryWindows8 references -->
    <script type="text/javascript" src="Scripts/jquery-2.0.2.js"></script>

    <style type="text/css">
        #divMessage {
            display:none;
            padding:10px;
            border: solid 1px white;
            background-color: #ff6a00;
        }
    </style>
</head>
<body>
    <button id="btnShow">Click Here</button>
    <div id="divMessage">
        Secret Message
    </div>

    <script type="text/javascript">
        $("#btnShow").click(function () {
            $("#divMessage").fadeToggle("slow");
        });
    </script>

</body>
</html>

The page in Listing 1.3 contains a Button and a DIV element. The contents of the DIV element are hidden by default (with display:none). When you click the button, the contents of the DIV fade slowly into view (see Figure 1.15).

FIGURE 1.15

FIGURE 1.15 Using jQuery to animate a DIV element

Microsoft worked directly with the jQuery team to ensure that jQuery 2.0 works correctly with Windows Store apps. As long as you are using a version of jQuery more recent than jQuery 2.0 then you should not encounter any issues.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020