Internationalization (i18n)

MiTensión supports multiple languages to make blood pressure tracking accessible to users worldwide. The app currently includes Spanish (default), English, and Galician localizations.

Supported Languages

Español (Spanish)

Default Languageres/values/strings.xmlApp name: MiTension

English

English Translationres/values-en/strings.xmlApp name: MyPressure

Galego (Galician)

Galician Translationres/values-gl/strings.xmlApp name: A miña Tensión

How It Works

Android’s resource system automatically selects the appropriate language based on the user’s device settings. If a translation isn’t available for the user’s language, the app falls back to Spanish (default).

The app responds immediately to language changes without requiring a restart.

String Resources Structure

All user-facing text is stored in XML resource files organized by category:

Resource Files Location

app/src/main/res/
├── values/              # Spanish (default)
│   └── strings.xml
├── values-en/           # English
│   └── strings.xml
└── values-gl/           # Galician
    └── strings.xml

String Categories

App Basics

Core app identification strings:

<string name="app_name">MiTension</string>

Translations:

Spanish: MiTension
English: MyPressure
Galician: A miña Tensión

Time Periods

Labels for the three daily measurement periods:

<string name="periodo_manana">Mañana</string>
<string name="periodo_tarde">Tarde</string>
<string name="periodo_noche">Noche</string>

English translations:

Morning, Afternoon, Night

Galician translations:

Mañá, Tarde, Noite

Measurement Labels

Blood pressure measurement terminology:

<string name="tension_alta_label">La Alta (sistólica)</string>
<string name="tension_alta_label_corta">La Alta</string>
<string name="tension_baja_label">La Baja (diastólica)</string>
<string name="tension_baja_label_corta">La Baja</string>
<string name="media_label">Media</string>

The app uses both long and short versions for different UI contexts.

Screen Titles

Dynamic titles with parameter placeholders:

<string name="titulo_medicion">%1$s - Medición %2$d/3</string>
<string name="detalle_dia_titulo">Detalles del día %1$d</string>
<string name="titulo_calendario">Calendario de Mi Tensión</string>

Action Buttons

Interactive button labels:

<string name="guardar">Guardar</string>
<string name="confirmar">Confirmar</string>
<string name="ver_calendario">Ver Calendario</string>
<string name="volver_al_calendario">Volver al Calendario</string>
<string name="anadir_nuevo_registro">Añadir Nuevo Registro</string>
<string name="pulsa_para_anadir">Pulsa para añadir</string>

Calendar Navigation

Messages and Feedback

User feedback messages:

<string name="error_campos_obligatorios">
  Ambos campos, Alta y Baja, son obligatorios.
</string>
<string name="guardado_con_exito">
  ¡Medición guardada con éxito!
</string>
<string name="error_periodo_lleno">
  Ya has completado los 3 registros para este período. 
  El siguiente período empieza en %s.
</string>
<string name="error_no_numerico">
  Error: Valor numérico inválido.
</string>

Notifications

Push notification content:

<string name="canal_notificaciones_nombre">
  Recordatorios de Medición
</string>
<string name="canal_notificaciones_descripcion">
  Notificaciones para recordar tomar la tensión.
</string>
<string name="notificacion_titulo">
  ¡Es hora de registrar tu tensión!
</string>
<string name="notificacion_texto">
  Aún te faltan %d mediciones para completar el período de la %s.
</string>

Blood Pressure Legend

Color-coded blood pressure classification:

<string name="leyenda_titulo">Leyenda de Tensión</string>
<string name="leyenda_normal">Normal</string>
<string name="leyenda_elevada">Elevada</string>
<string name="leyenda_alta_1">Alta (Hipertensión 1)</string>
<string name="leyenda_alta_2">Alta (Hipertensión 2)</string>
<string name="leyenda_crisis">Crisis Hipertensiva</string>
<string name="leyenda_baja">Baja (Hipotensión)</string>

These classifications follow standard medical guidelines.

String Formatting

MiTensión uses Android’s string formatting for dynamic content:

Format Specifiers

String Parameters

Use %1$s, %2$s, etc. for string values:

<string name="titulo_medicion">
  %1$s - Medición %2$d/3
</string>

getString(R.string.titulo_medicion, "Mañana", 2)
// Output: "Mañana - Medición 2/3"

Integer Parameters

Use %d or %1$d for numbers:

<string name="notificacion_texto">
  Aún te faltan %d mediciones para 
  completar el período de la %s.
</string>

getString(
  R.string.notificacion_texto, 
  2, 
  "tarde"
)

Adding New Languages

To add support for a new language:

Create Resource Directory

Create a new values directory with the language code:

mkdir app/src/main/res/values-fr  # For French

Common language codes:

values-fr - French
values-de - German
values-pt - Portuguese
values-it - Italian

Copy String Template

Copy the default strings.xml to the new directory:

cp app/src/main/res/values/strings.xml \
   app/src/main/res/values-fr/strings.xml

Translate Strings

Open the new strings.xml and translate all string values.

Keep the XML structure and parameter placeholders (%1$s, %d) identical. Only translate the visible text.

Example:

<!-- Original (Spanish) -->
<string name="guardar">Guardar</string>

<!-- French translation -->
<string name="guardar">Enregistrer</string>

Test Translations

Test the app with the new language:

Open device Settings → Language
Add and select the new language
Open MiTensión and verify all screens
Check for truncated text or layout issues

Translation Guidelines

Follow these best practices when adding or updating translations.

Do’s and Don’ts

Maintain Consistency

✅ Use consistent terminology throughout the app✅ Keep the same tone and formality level✅ Preserve parameter placeholders exactly❌ Don’t translate technical terms unnecessarily❌ Don’t change parameter order without updating code

Consider Text Length

Some languages use longer words than others. Consider:

Button labels should be concise
Allow for 30-40% text expansion
Test UI layouts with different languages
Use short versions where space is limited

Example:

<string name="tension_alta_label">
  La Alta (sistólica)
</string>
<string name="tension_alta_label_corta">
  La Alta
</string>

Handle Plurals

For quantities that may be singular or plural, use plural resources:

<plurals name="measurement_count">
  <item quantity="one">%d medición</item>
  <item quantity="other">%d mediciones</item>
</plurals>

Preserve Special Characters

XML special characters must be escaped:

& for &
< for <
> for >
" for ”
' or \' for ’

Example:

<string name="notificacion_titulo">
  It\'s time to record your blood pressure!
</string>

Accessing Strings in Code

In Composables

Use stringResource() in Jetpack Compose:

import androidx.compose.ui.res.stringResource

@Composable
fun MeasurementScreen() {
    val title = stringResource(R.string.titulo_medicion, "Mañana", 1)
    
    Text(text = title)
}

In ViewModels

ViewModels should NOT access string resources directly. Pass formatted strings from the UI layer.

Correct approach:

// In Composable
val errorMessage = stringResource(R.string.error_campos_obligatorios)
LaunchedEffect(viewModel.error) {
    if (viewModel.error) {
        showSnackbar(errorMessage)
    }
}

// In ViewModel
fun validateFields(alta: Int?, baja: Int?) {
    if (alta == null || baja == null) {
        _error.value = true  // Emit error state
    }
}

In Background Workers

Workers have access to Context:

class ReminderWorker(context: Context, params: WorkerParameters) 
    : Worker(context, params) {
    
    override fun doWork(): Result {
        val title = applicationContext.getString(
            R.string.notificacion_titulo
        )
        val text = applicationContext.getString(
            R.string.notificacion_texto,
            2,
            "tarde"
        )
        
        showNotification(title, text)
        return Result.success()
    }
}

Testing Translations

Manual Testing

Change Device Language

Settings → System → Languages & input → Languages

Verify All Screens

Navigate through every screen and check:

All text is translated
No truncated text
Layouts adjust properly
Dialogs display correctly

Test Edge Cases

Very long text strings
Special characters
Notifications
Error messages

Automated Testing

While automated translation testing is limited, you can verify resource completeness:

@Test
fun `all languages have same string keys`() {
    val defaultStrings = getStringKeys("values")
    val englishStrings = getStringKeys("values-en")
    val galicianStrings = getStringKeys("values-gl")
    
    assertEquals(defaultStrings, englishStrings)
    assertEquals(defaultStrings, galicianStrings)
}

Current Translation Coverage

Spanish

100% Complete52 strings

English

100% Complete52 strings

Galician

100% Complete52 strings

All supported languages have complete translation coverage with no missing strings.

Best Practices Summary

Always translate all strings - Incomplete translations break the user experience
Test with actual devices - Emulators may not catch all layout issues
Keep strings.xml organized - Use comments to group related strings
Avoid hardcoded text - Never put user-visible text directly in code
Consider RTL languages - If adding Arabic or Hebrew, test right-to-left layouts
Update all languages together - When adding new features, translate immediately
Review translations - Have native speakers review translations when possible

Need Help?

For questions about internationalization:

Check the Contributing Guidelines
Review Android’s Localization documentation
Open an issue on GitHub for translation help

Additional Resources

Internationalization (i18n)

Supported Languages

Español (Spanish)

English

Galego (Galician)

How It Works

String Resources Structure

Resource Files Location

String Categories

String Formatting

Format Specifiers

String Parameters

Integer Parameters

Adding New Languages

Translation Guidelines

Do’s and Don’ts

Accessing Strings in Code

In Composables

In ViewModels

In Background Workers

Testing Translations

Manual Testing

Automated Testing

Current Translation Coverage

Spanish

English

Galician

Best Practices Summary

Need Help?

Build docs developers (and LLMs) love

Additional Resources

​Supported Languages

Español (Spanish)

English

Galego (Galician)

​How It Works

​String Resources Structure

​Resource Files Location

​String Categories

​String Formatting

​Format Specifiers

String Parameters

Integer Parameters

​Adding New Languages

​Translation Guidelines

​Do’s and Don’ts

​Accessing Strings in Code

​In Composables

​In ViewModels

​In Background Workers

​Testing Translations

​Manual Testing

​Automated Testing

​Current Translation Coverage

Spanish

English

Galician

​Best Practices Summary

​Need Help?

Build docs developers (and LLMs) love

Supported Languages

How It Works

String Resources Structure

Resource Files Location

String Categories

String Formatting

Format Specifiers

Adding New Languages

Translation Guidelines

Do’s and Don’ts

Accessing Strings in Code

In Composables

In ViewModels

In Background Workers

Testing Translations

Manual Testing

Automated Testing

Current Translation Coverage

Best Practices Summary

Need Help?