Invenio-i18n

3.5.0 verified Fri May 01 auth: no python

Invenio internationalization (I18N) module. Provides Flask-based i18n support, locale selector, and translation utilities for Invenio repositories. Current version 3.5.0, requires Python >=3.9.

pip install invenio-i18n

Common errors

error ImportError: cannot import name 'InvenioI18N' from 'invenio_i18n' ↓

cause Older version of invenio-i18n (pre-1.0) had different import path.

fix

Upgrade to latest: pip install --upgrade invenio-i18n

error RuntimeError: babel data directory not found ↓

cause Missing translation files; often due to incomplete pip install or without Flask-BabelEx.

fix

Ensure Flask-BabelEx is installed and translation data is packaged: pip install Flask-BabelEx

Warnings

breaking Invenio-i18n 3.x requires Flask-BabelEx >= 2.x and is not compatible with plain Flask-Babel. Ensure Flask-Babel is not installed. ↓

fix Use Flask-BabelEx explicitly: pip install Flask-BabelEx. Do not install Flask-Babel.

deprecated The 'I18N_LANGUAGES' config key is deprecated in favor of 'I18N_AVAILABLE_LANGUAGES' since version 3.3.0. ↓

fix Use app.config['I18N_AVAILABLE_LANGUAGES'] instead of I18N_LANGUAGES.

gotcha If you override 'current_i18n' from Flask-BabelEx, ensure you import from invenio_i18n, not flask_babelex, as the internal wrapper may change. ↓

fix Always import current_i18n from invenio_i18n.

Imports

InvenioI18N
```
from invenio_i18n import InvenioI18N
```
current_i18n
wrong
```
from flask_babelex import current_i18n
```
correct
```
from invenio_i18n import current_i18n
```
Flask-BabelEx is a dependency but its symbols are re-exported via invenio_i18n

Quickstart

Minimal Flask app with Invenio-I18N initialization and language detection.

from flask import Flask
from invenio_i18n import InvenioI18N

app = Flask(__name__)
app.config['I18N_LANGUAGES'] = [('en', 'English'), ('fr', 'Fran\u00e7ais')]
ext = InvenioI18N(app)

@app.route('/')
def index():
    from invenio_i18n import current_i18n
    return current_i18n.locale.language

if __name__ == '__main__':
    app.run()