getLanguage

Category: Application Control

Namespace: web.app.getLanguage

Description

Get the current language of the application. Returns the language that was actually loaded at startup — either the user's selection (if the app is configured for multilingual mode) or the project's default language.

In multilingual mode (Builder setting: "All Languages = True"), the user is prompted to choose a language on first launch, and their choice is remembered. This method returns that saved choice.

In single language mode, it returns the project's configured target language.

Syntax

const language = await web.app.getLanguage();

Parameters

None

Returns

Promise<string> - The language name as a string (e.g., "English", "Spanish", "French", "German")

Example

Simple example

const lang = await web.app.getLanguage();
console.log('App language:', lang);

Practical example — set page language attribute

const lang = await web.app.getLanguage();

const langMap = {
    'English': 'en',
    'Spanish': 'es',
    'French': 'fr',
    'German': 'de',
    'Portuguese': 'pt',
    'Italian': 'it',
    'Japanese': 'ja',
    'Chinese': 'zh',
    'Korean': 'ko',
    'Russian': 'ru'
};

document.documentElement.lang = langMap[lang] || 'en';

Advanced example — load translation strings

async function initLocalization() {
    const lang = await web.app.getLanguage();
    
    const translations = {
        'English': {
            greeting: 'Welcome',
            save: 'Save',
            cancel: 'Cancel',
            confirm: 'Are you sure?'
        },
        'Spanish': {
            greeting: 'Bienvenido',
            save: 'Guardar',
            cancel: 'Cancelar',
            confirm: '¿Estás seguro?'
        },
        'French': {
            greeting: 'Bienvenue',
            save: 'Enregistrer',
            cancel: 'Annuler',
            confirm: 'Êtes-vous sûr?'
        }
    };
    
    // Fall back to English if language not in our translations
    const t = translations[lang] || translations['English'];
    
    // Apply translations to UI
    document.getElementById('greeting').textContent = t.greeting;
    document.getElementById('btn-save').textContent = t.save;
    document.getElementById('btn-cancel').textContent = t.cancel;
}

document.addEventListener('DOMContentLoaded', initLocalization);

Use Cases

Set the lang attribute on <html> for accessibility and SEO
Load the correct translation strings for the UI
Format dates, numbers, and currency based on locale
Display language-specific content or instructions
Choose the right help documentation to show
Adjust text direction (LTR/RTL) based on language
Log the user's language for analytics

Error Handling

Falls back to "English" if the language cannot be determined.

const lang = await web.app.getLanguage();
// Always returns a string — never null or undefined
console.log('Language:', lang);

Performance Tips

Call at startup to initialize your UI language
The user can change the language at runtime via the tray menu — if your app needs to react to that, call getLanguage() again after a page reload or at key moments

let appLanguage = 'English';

document.addEventListener('DOMContentLoaded', async () => {
    appLanguage = await web.app.getLanguage();
    applyTranslations(appLanguage);
});

web.app.getCmdArgs() - Get command line arguments
web.app.licensed() - Check if licensed
web.app.packageName() - Get license package name

Notes

In multilingual apps, the user's language choice is stored in the Windows registry and persists across sessions
The user can change their language at runtime via the tray menu Language item (if multilingual mode is enabled) — getLanguage() returns the language at the time of the call
Language names match the resource names configured in the Builder (e.g., "English", "Spanish", not ISO codes like "en", "es")
If you need ISO language codes, create a mapping from the language name (see practical example above)