# Flask Babel

***

**1. Basic Internationalization (I18n) with Flask-Babel**

```python
from flask import Flask, render_template
from flask_babel import Babel

app = Flask(__name__)
babel = Babel(app)

@babel.localeselector
def get_locale():
    return request.accept_languages.best_match(["en", "fr"])

@app.route("/")
def index():
    return render_template("index.html")
```

**2. Set Default Locale**

```python
babel.default_locale = "en"
```

**3. Automatic Contextualization**

```python
with app.test_request_context():
    get_locale() == "en"
```

**4. Get Current Locale**

```python
from flask_babel import get_locale

get_locale() == "en"
```

**5. Get List of Available Locales**

```python
from flask_babel import get_available_locales

get_available_locales() == ["en", "fr"]
```

**6. Set Default Timezone**

```python
babel.default_timezone = "UTC"
```

**7. Automatic Contextualization (Timezones)**

```python
with app.test_request_context():
    get_timezone() == "UTC"
```

**8. Get Current Timezone**

```python
from flask_babel import get_timezone

get_timezone() == "UTC"
```

**9. Get List of Available Timezones**

```python
from flask_babel import get_available_timezones

get_available_timezones() == ["UTC", "America/New_York"]
```

**10. Custom Locale Selector**

```python
@babel.localeselector
def get_locale():
    cookie = request.cookies.get("lang")
    if cookie in ["en", "fr"]:
        return cookie
    return request.accept_languages.best_match(["en", "fr"])
```

**11. Using the `gettext` Function**

```python
from flask_babel import gettext

gettext("Hello") == "Bonjour"
```

**12. Using the `ngettext` Function (Pluralization)**

```python
from flask_babel import ngettext

ngettext("apple", "apples", 2) == "2 apples"
```

**13. Using Lazy Translation Objects**

```python
from flask_babel import lazy_gettext

translation = lazy_gettext("Hello")
str(translation) == "Bonjour"
```

**14. Using the `translate` Filter in Templates**

```python

<div data-gb-custom-block data-tag="trans" data-0='Hello'></div>

 == "Bonjour"
```

**15. Using the `ngettext` Filter in Templates (Pluralization)**

```python

<div data-gb-custom-block data-tag="trans" data-0='apples' data-n='2'></div>

 == "2 apples"
```

**16. Lazy Translation Objects in Templates**

```python

<div data-gb-custom-block data-tag="trans" data-0='Hello' data-1='Hello'></div>

 == "Bonjour"
```

**17. Custom Translation Functions**

```python
babel.add_domain("messages")

@babel.localeselector
def get_lang():
    return request.cookies["lang"]

@babel.domain_selector
def get_domain():
    return "messages"
```

**18. Translations in Different Files**

```python
babel.messagespath = ["/path/to/translations", "/path/to/fallback"]
```

**19. Using the `lazy_gettext` Function in Forms**

```python
from flask_wtf import FlaskForm
from wtforms.fields import StringField
from flask_babel import lazy_gettext

class MyForm(FlaskForm):
    name = StringField(lazy_gettext("Name"))
```

**20. Translations in Forms with Validation Messages**

```python
class MyForm(FlaskForm):
    name = StringField(
        lazy_gettext("Name"),
        validators=[validators.Required(lazy_gettext("Name is required."))]
    )
```

**21. Automatic Translation Context in Forms**

```python
with app.test_request_context("/fr"):
    f = MyForm()
    f.name.label.text == "Nom"
```

**22. Flask-WTForms Integration with Lazy Translation**

```python
class MyForm(Form):
    name = StringField(lazy_gettext("Name"), render_kw={"placeholder": lazy_gettext("Enter your name")})
```

**23. Flask-Admin Integration**

```python
from flask_admin import Admin, BaseView

class MyView(BaseView):
    @babel.localeselector
    def get_locale(self):
        return request.args.get("lang")
```

**24. Jinja2 Integration**

```python

<div data-gb-custom-block data-tag="if" data-0='en' data-1='en'>

    English content

<div data-gb-custom-block data-tag="elif" data-0='fr' data-1='fr'></div>

    French content

</div>
```

**25. Flask-Script Integration**

```python
from flask_script import Manager

manager = Manager(app)

@manager.command
def translate():
    from flask_babel import compile_catalog
    compile_catalog(app.config["BABEL_COMPILE_CATALOG"])
```

**26. Loading Translations from Files**

```python
from os import path

babel.load_translations(
    path.abspath(path.join(path.abspath(path.dirname(__file__)), "../translations"))
)
```

**27. Using Translations from Different Directories**

```python
babel.messagespath = ["/path/to/translations", "/path/to/fallback"]
```

**28. Get the Translation for a Specific Domain**

```python
from flask_babel import gettext

gettext("Hello", domain="messages") == "Bonjour"
```

**29. Translation Extensibility**

```python
class MyTemplate(MTSafeTemplate):
    def __getitem__(self, key):
        translation = gettext(key)
        if translation != key:
            return translation
        return super().__getitem__(key)
```

**30. Using Translations with String Formatting**

```python
from flask_babel import gettext

gettext("Hello %s", "Alice") == "Hello Alice"
```

**31. Dynamic Translation Context**

```python
with app.test_request_context("/fr?foo=bar"):
    gettext("Hello") == "Bonjour"
```

**32. Setting Locale in the Query String**

```python
@babel.localeselector
def get_locale():
    return request.args.get("lang")
```

**33. Translation for Multiple Languages**

```python
babel.available_languages = ["en", "fr", "es"]
```

**34. Using Translations in SQL Queries**

```python
from flask_babel import get_sqlalchemy_connector

db.engine.dialect.connector = get_sqlalchemy_connector()
```

**35. Custom Timezone Selector**

```python
@babel.timezoneselector
def get_timezone():
    return request.cookies.get("tz")
```

**36. Using the `Render` Function to Format Dates**

```python
from flask_babel import render_template

render_template("date.html", date=datetime.utcnow())
```