example/README.md

Example #

Step 1: Add dependencies #

dependencies:
  fast_i18n: ^1.1.2

dev_dependencies:
  build_runner: any

Step 2: Create JSON files #

Create these files inside your lib directory. Preferably in one common package like lib/i18n.

strings.i18n.json

{
  "hello": "Hello $name",
  "save": "Save",
  "login": {
    "success": "Logged in successfully",
    "fail": "Logged in failed"
  }
}

strings_de.i18n.json

{
  "hello": "Hallo $name",
  "save": "Speichern",
  "login": {
    "success": "Login erfolgreich",
    "fail": "Login fehlgeschlagen"
  }
}

Step 3: Generate the dart code #

flutter packages pub run build_runner build

Step 4: Initialize #

Widget build(BuildContext context) {                                    

    // a: use device locale (StatefulWidget for rerendering)
    LocaleSettings.useDeviceLocale().then((_) {
      setState((){});
    });
 
    // b: use specific locale
    LocaleSettings.setLocale('de');
 
    // c: use default locale
    // *do nothing*

    return MaterialApp(
      // [...]
    );

Step 5: Use your translations #

// raw string
String translated = t.hello(name: 'Tom');

// inside component
Text(t.login.success)

Useful functions #

When the dart code has been generated, you will see some useful classes and functions

t - the most important translate variable

LocaleSettings.useDeviceLocale() - use the locale of the device

LocaleSettings.setLocale('de') - change the locale

LocaleSettings.currentLocale - get the current locale