Making the App World-Ready
At this point, our HelloRealWorld app still only says “hello” to the English-speaking parts of the world. The Windows Store serves hundreds of markets and over a hundred different languages, so ignoring them greatly reduces the audience for your app. Making your app world-ready involves two things: globalization and localization.
Globalization refers to making your app act appropriately for different markets without any changes or customizations. An example of this is formatting the display of currency correctly for the current region without writing special-case logic. The Windows.Globalization namespace contains a lot of functionality for handling dates and times, geographic regions, number formatting, and more. Plus, built-in XAML controls such as DatePicker and TimePicker, discussed in Chapter 15, are globalization-ready. For many apps, these features might not apply.
Localization, which is relevant for practically every app, refers to explicit activity to adapt an app to each new market. The primary example of this is translating text in your user interface to different languages and then displaying the translations when appropriate. Performing this localization activity is the focus of this section.
To make an app ready for localization, you should remove hardcoded English strings that are user-visible, and instead mark such elements with a special identifier unique within the app. Listing 1.6 updates our XAML from Listing 1.2 to do just that.
LISTING 1.6 MainPage.xaml—Markup with User-Visible English Text Removed
<
Page
x
:
Class
="HelloRealWorld.MainPage"
xmlns
="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns
:
x
="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns
:
local
="using:HelloRealWorld"
xmlns
:
d
="http://schemas.microsoft.com/expression/blend/2008"
xmlns
:
mc
="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc
:
Ignorable
="d">
<
Grid
Background
="{
ThemeResource
ApplicationPageBackgroundThemeBrush
}">
<
StackPanel
x
:
Uid
="Panel"
Name
="stackPanel"
Margin
="100">
<
TextBlock
x
:
Uid
="Greeting"
FontSize
="80"
TextWrapping
="WrapWholeWords"
Margin
="12,48"
/>
<
TextBlock
x
:
Uid
="EnterName"
FontSize
="28"
Margin
="12"
/>
<
Grid
>
<
Grid.ColumnDefinitions
>
<
ColumnDefinition
/>
<
ColumnDefinition
Width
="Auto"/>
</
Grid.ColumnDefinitions
>
<
TextBox
Name
="nameBox"
Margin
="12"/>
<
Button
x
:
Uid
="GoButton"
Grid.Column
="1"
Click
="Button_Click"
/>
</
Grid
>
<
TextBlock
Name
="result"
FontSize
="28"
Margin
="12"/>
</
StackPanel
>
</
Grid
>
</
Page
>
The x:Uid marking is completely independent from an element’s Name. The former is specifically for the localization process, and the latter is for the benefit of code-behind. Note that Listing 1.6 not only removes the three hardcoded strings from the two TextBlocks and the Button, but it also removes the explicit "Blue" color from the StackPanel! This way, we can customize the color for different languages in addition to the text.
With the IDs in place and the text and color for English removed, we need to add them back in a way that identifies them as English-only. To do this, add a new folder to the solution called en. This is the language code for all variations of English. If you want to target the United Kingdom separately, you could add a folder called en-GB. If you want to target Canada separately, you could add a folder called en-CA. And so forth.
Right-click on the en folder and select Add, New Item, then pick Resources file from the General tab. The default name of Resources.resw is fine. This file is a table for all your language-specific strings. Figure 1.10 shows this file populated for English.
FIGURE 1.10 The Resources.resw file in the en folder is populated with English-specific values.
Each value must be given a name of the form UniqueId.PropertyName. UniqueId must match the x:Uid value for the relevant element, so the Panel.Background entry in Figure 1.10 sets Background to Blue on the StackPanel marked with x:Uid="Panel" in Listing 1.6. From the listing, it’s not obvious that GoButton’s relevant property is called Content, unlike the TextBlocks’ property called Text, but as you learn about the different elements throughout this book, you’ll understand which properties to set.
After filling out the Resources.resw file, you can run the HelloRealWorld app and the result is identical to what we saw earlier in Figures 1.6 and 1.7. However, the app is now ready to be localized for other languages.
We could add additional folders named after language codes and manually populate translated resources with the help of a knowledgeable friend, a professional translator, or translation software. Depending on the current user’s language settings, the appropriate resources are chosen at runtime, with a fallback to the default language if no such resources exist.
However, a better option exists. To take advantage of it, you must download and install the Multilingual App Toolkit from the Windows Dev Center. Once you do this, you can select Enable Multilingual App Toolkit from Visual Studio’s Tools menu. This automatically adds an .xlf file to a new subfolder added to your project called MultilingualResources for a test-only language called Pseudo Language.
We’ll leverage the Pseudo Language in a moment, but first let’s add support for a second real language: Traditional Chinese. To do this, right-click on your project in Solution Explorer and select Add translation languages.... This produces the dialog shown in Figure 1.11.
FIGURE 1.11 The Multilingual App Toolkit automates the process for supporting new languages.
In this dialog, Pseudo Language and our default English language is already selected, but we can scroll down and select Chinese (Traditional) [zh-Hant] from the list. After pressing OK, the MultilingualResources folder now has two .xlf files: one for Pseudo Language, and one for Traditional Chinese.
Now rebuild the HelloRealWorld app. This populates each .xlf file with a “translation” for each item from the default language .resw file. Initially, each translation is just the duplicated English text. However, for some languages, such as the two we’ve chosen, you can generate machine translations based on the Microsoft Translator service! To do this for the entire file, right-click on each .xlf file and select Generate machine translations. Voilà! Now we’ve got initial translations for all of our resources, which you can see by opening each .xlf file and examining the list inside the multilingual editor. This is shown in Figure 1.12.
FIGURE 1.12 Each .xlf file contains machine-generated initial translations, courtesy of Microsoft Translator.
Your willingness to trust the results from machine translation is a personal decision, but at least machine translation is a good starting point. (Notice that the generated translations are automatically placed in a “Needs Review” state.) That said, we definitely don’t want the Blue text translated to ! This isn’t a user-visible string, and is not a valid value for Background. Instead, let’s “translate” it to Red, which will serve as our language-specific background color. Similarly, we don’t want Blue’s Pseudo Language translation of , so let’s change that to Green.
We have one more change to make. We don’t want “Hello, English-speaking world!” to be translated to Chinese, but rather “Hello, Chinese-speaking world!” Both Microsoft Translator and a colleague tell me that “!” is a valid translation, so we can paste that into the appropriate spot of the Chinese .xlf file.
After rebuilding the project, we are now ready to test the localized versions of HelloRealWorld. Just as if we had manually added separate .resw files in per-language folders, the translated resources are used automatically based on the current Windows language settings.
To change the default language used by Windows, you can either use the PC Settings app or the desktop Control Panel. In PC Settings, this can be found under Time & language; Region & language. In Control Panel, it’s under Clock, Language, and Region; Language. Add Chinese (Traditional) and make it the default language to test the Traditional Chinese resources.
To add Pseudo Language (and make it the default language), you have to use a hidden trick in Control Panel. After clicking Add languages, type qps-ploc in the search box for the entry called English (qps-ploc) to appear. You must type the whole thing for this to work! This language is hidden in this way because no normal user should ever enable it.
Figure 1.13 shows the result of running HelloRealWorld when Windows is set to use each of the two non-English languages. These changes are handled completely by the resource-loading mechanism. Other than the switch to marking elements with x:Uid, no code changes were needed. This figure also highlights Pseudo Language’s knack for using really long strings that can highlight potential weaknesses in your app’s layout.
FIGURE 1.13 HelloRealWorld now acts appropriately for Traditional Chinese and for the test-only Pseudo Language.