Building Windows Store Apps with with HTML5 and JavaScript
In this chapter, I introduce you to the basics of building Windows Store apps. I start off by explaining how a Windows Store app differs from a traditional Windows desktop application. You learn what makes a Windows Store app a Windows Store app.
Feeling fearless and bold, and hoping that you too feel fearless and bold, I next guide you through building your first Windows store app. You learn how to take advantage of the features of Microsoft Visual Studio 2013 to build, run, and debug a Windows Store app.
Next, we dive into a discussion of the fundamental elements of a Windows Store app. You learn how a Windows Store app is forged out of HTML5, JavaScript, the Windows Library for JavaScript, and the Windows Runtime.
Finally, we get to the money part. I explain how you can publish your Windows Store app to the Windows Store and start collecting those dollars.
What Is a Windows Store App?
I can still remember the first time that I used an iPhone. When you scroll the screen on an iPhone, the screen actually bounces! And when you add an email to the trash, the email gets sucked into the trashcan! It’s as if there is a little universe inside an iPhone and it follows our physical laws.
For some reason—that I have not explored and that I do not completely understand—this illusion that there is a second universe inside my iPhone makes me happy. It makes interacting with an iPhone fun.
Now we come to Windows. Except for the dancing card thing in Windows Solitaire, I can’t think of anything in Windows that has ever created this same sense of fun. I can’t remember the last time that Windows made me laugh or brought me joy.
With Windows Store apps, Microsoft has finally acknowledged that user experience matters—in a big way. The heart of Windows Store apps is a set of user experience principles named the Microsoft design style principles. By embracing the Microsoft design style principles, you can create Windows Store apps that seem more alive and that are a pleasure to use.
Microsoft Design Style Principles
The Microsoft design style principles is a set of user experience design principles developed by Microsoft in the context of building the Windows Phone, Xbox Live, and the (now defunct) Zune. You also can see the Microsoft design principles applied to Microsoft websites such as Microsoft SkyDrive and the Windows Azure Portal. Get ready. Here they are:
Show pride in craftsmanship
- Devote time and energy to small things that are seen often by many.
- Engineer the experience to be complete and polished at every stage.
Do more with less
- Solve for distractions, not discoverability. Let people be immersed in what they love and they will explore the rest.
- Create a clean and purposeful experience by leaving only the most relevant elements on screen so people can be immersed in the content.
Be fast and fluid
- Let people interact directly with content, and respond to actions quickly with matching energy.
- Bring life to the experience, create a sense of continuity and tell a story through meaningful use of motion.
Be authentically digital
- Take full advantage of the digital medium. Remove physical boundaries to create experiences that are more efficient and effortless than reality.
- Embrace the fact that we are pixels on a screen. Design with bold, vibrant and crisp colors and images that go beyond the limits of real-world material.
Win as one
- Leverage the ecosystem and work together with other apps, devices and the system to complete scenarios for people.
- Fit into the UI model to reduce redundancy. Take advantage of what people already know to provide a sense of familiarity, control, and confidence.
When I first read these principles, my initial reaction was that they seemed overly abstract and squishy. Exactly the type of principles that would be created by beret-wearing user experience guys.
But then, when I saw how the principles were applied in practice—when building actual Windows Store apps—I started to develop a better appreciation for these principles.
Take the “Do more with less” design principle. One of the distinctive features of a Windows Store app is the lack of chrome. Ironically, a Windows Store app is a Windows app without the window. Windows Store apps are full-screen apps.
This lack of chrome makes it easier to concentrate on the content of the application. For example, Windows 8 includes two version of Internet Explorer: a desktop version and a full-throated Windows 8 version that follows the Microsoft design style principles.
I really prefer using the Windows 8 version of Internet Explorer over the desktop version. When using the Windows 8 version, all you see is the web page, which is the point of the application in the first place.
Or consider the “Be fast and fluid” principle. The reason that I like interacting with my iPhone so much is the illusion of motion, and this illusion is created by the judicious use of animations: On an iPhone, objects bounce and wobble.
When building a Windows Store app, you are encouraged to take advantage of animations. For example, if you use the standard ListView control—which we discuss in detail later in this book—then you get animations when you add or remove items. When you add an item to a ListView, it not only appears, it glides into place. When you remove an item, it doesn’t just disappear, items above and below it collapse into place.
Common Features of Windows Store Apps
Windows Store apps are applications that follow the Microsoft design style principles. Furthermore, Windows Store apps are designed to run on the Windows 8 or Windows RT operating system.
All Windows Store apps have a common set of features. Let me explain these features by pointing them out in the context of the Bing News app that’s included with Windows 8.
Support for Keyboard, Mouse, Touch, and Stylus
One of the most distinctive characteristics of a Windows Store app is its oversized tiles and buttons and generous use of whitespace. All of this user interface (UI) roominess makes Windows Store apps friendly to fat fingers.
Windows Store apps are designed to work equally well when used on a touch-only tablet and when used on a desktop computer with a keyboard and mouse. Windows Store apps are designed to be gropeable.
The nice thing about how Windows 8 works is that you don’t need to put a lot of thought into supporting touch as a developer. As long as you stick with the standard WinJS controls, you get both keyboard and touch support for free.
Using the App Bar and Nav Bar
Figure 1.1 contains a screenshot of the Windows 8 Bing News app with the home page of Fox News open. Notice that the only thing that you see is the content of Fox News. No toolbars, no menus, no status bars.
FIGURE 1.1 Windows 8 Bing News app
In a Windows Store app, you hide all of your commands in the app bar. The app bar appears only when you swipe from the bottom or top of the screen or you right-click the screen.
The app bar for the Bing News app includes commands such as Pin to Start, Refresh, and Help. You can see the app bar at the bottom of Figure 1.2.
FIGURE 1.2 Using the app bar and nav bar
Notice in Figure 1.2 that there is another bar at the top of the screen. This bar is called the nav bar and you use it to navigate. In the case of the Bing News app, the nav bar enables you to navigate to different news sources such as the Wall Street Journal, Fox News, and the New York Times.
Using Charms
If you swipe from the right edge of the screen or mouse to either of the right corners or press the keyboard combination Win+C then the charms are revealed (see Figure 1.3).
FIGURE 1.3 Viewing charms
Here’s a list of the standard charms:
- Search—Enables you to search content in the current app and other apps
- Share—Enables you to share content in the current app with other apps
- Start—Navigates you to the Start screen
- Devices—Enables you to connect to a device
- Settings—Enables you to configure both app settings and system settings
These charms provide you with standard locations to place common application functionality. For example, all Windows Store app settings should appear in the Settings charm (see Figure 1.4). This makes it much easier for users to find your settings.
FIGURE 1.4 The Settings charm
When you are building a Windows Store app, you don’t build your own Settings menu. Instead, you extend the Settings charm with your custom app settings. I discuss the details of doing this in Chapter 6, “Menus and Flyouts.”
Different App Sizes and Orientations
Every Windows 8.1 app supports a minimum width of either 500 pixels or 320 pixels. For example, if a Windows 8.1 app has a minimum horizontal size of 500 pixels then the app can be resized to any size between 500 pixels and the maximum screen size of the device where the app is displayed.
If you are lucky enough to have a sufficiently large screen, then you can display multiple running apps side by side (up to four apps per monitor). For example, Figure 1.5 illustrates three Windows 8.1 apps running side by side (the Calendar, Maps, and News apps).
FIGURE 1.5 Three Windows 8.1 apps side by side
A Windows Store app also must work when used with different device orientations. For example, when an app is viewed on a tablet computer, the user always has the option of rotating your app from a landscape to a portrait orientation.
When building Windows Store apps, you need to design the app so it works with different screen resolutions and orientations. At any moment, the horizontal resolution of your app could be dramatically changed. I discuss how to handle switching between different resolutions in Chapter 11, “App Events and States.”
People, Not Machines, Use Windows Store Apps
When you buy a Windows Store app, the app is licensed per user and not per machine. When you buy an app, you can use the app on up to five machines—including both tablets and desktops—associated with your user account. You can view and install all of your purchased apps from the Windows Store by right-clicking within the Store app and selecting Your Apps.
Better yet, data from your apps can be shared across multiple machines (roaming application data). So, if you are using an app to read an article on your tablet PC on the bus and then you open the same app on your desktop PC at work, you won’t lose your place in the article.
Currently, every Windows Store app gets 100KB of roaming application data. Windows 8.1 handles synchronizing this data between different machines for you automatically.
Closing a Windows Store App
Now close a Windows Store app by moving your cursor over the x at the top-right of the screen. Ha! Tricked you! There is no close button in a Windows Store app because there is no chrome.
When interacting with Windows Store apps, there is no obvious way to close an app. This is intentional. Instead of closing a Windows Store app, you are encouraged to simply switch to another running app (by swiping from the left edge of the screen) or launch a new app (by selecting a new app from the Start screen).
When you design a Windows Store app, you must design the app with the knowledge that a user might switch back and forth to your running app at any time. In Chapter 11 I discuss how you can gracefully resume an app after it has been suspended.