Previewing localizations
Test localizations in the SwiftUI preview or the Interface Builder preview.
Overview
You can preview localizations early in development while you lay out your app’s interface for both SwiftUI and Interface Builder apps. For SwiftUI apps, you need to add the language or import the localization before you preview it, described in Adding support for languages and regions and Importing localizations. For Interface Builder apps, you can first preview the interface in pseudolanguages and then later in the localizations you add.
Add localizations to a SwiftUI preview
For SwiftUI apps, you can preview a localization by setting the locale environment variable in your code. Use the environment(_:_:) function to set the locale for all views in the view hierarchy of a SwiftUI preview. For example, if you add German to your project, you can set the locale to German (de):
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
.environment(\.locale, .init(identifier: "de"))
}
}To preview right-to-left languages, also set the layoutDirection key to LayoutDirection.rightToLeft.
To preview multiple localizations, add additional previews to your code and set the locale environment value for each. The localizations appear in the SwiftUI preview.
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Preview localizations in Interface Builder
For Interface Builder, you can preview localizations any time during development by choosing localizations including pseudolanguages in the preview. You don’t need to build and run your app to see the preview.
In Interface Builder, select the desired view controller. Click the Adjust Editor Options button in the upper-right corner, then choose Preview. A preview of the layout appears to the right of the canvas.
In the preview area, select a preview or click in the background to deselect all previews. If you don’t select a preview, you’ll change the language of all previews. Click the language button—for example, English—in the lower-right corner. In the pop-up menu that appears, choose a localization or pseudolanguage.
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