Tools for using Babel with Django
This package contains various utilities for integration of Babel
_ into the
Django
_ web framework:
- A message extraction plugin for Django templates.
- A middleware class that adds the Babel
Locale
_ object to requests. - A set of template tags for date and number formatting.
Babel provides a message extraction framework similar to GNU xgettext
, but
more extensible and geared towards Python applications. While Django does
provide wrapper scripts
_ for making the use of xgettext
more
convenient, the extraction functionality is rather limited. For example, you
can't use template files with an extension other than .html
, and everything
needs to be in your project package directory.
Extraction Method Mapping
^^^^^^^^^^^^^^^^^^^^^^^^^
So enmerkar comes with an extraction method plugin that can extract
localizable messages from Django template files. Python is supported out of the
box by Babel. To use this extraction functionality, create a file called
babel.cfg
in your project directory (the directory above your project
package), with the content:
.. code-block:: ini
[django: templates/**.*]
[django: mypkg/*/templates/**.*]
[python: mypkg/**.py]
This instructs Babel to look for any files in the top-level templates
directory, or any files in application templates
directories, and use the
extraction method named “django” to extract messages from those template files.
You'll need to adjust those glob patterns to wherever you my be storing your
templates.
Also, any files with the extension .py
inside your package directory (replace
“mypkg” with the actual name of your Django project package) are processed by
the “python” extraction method.
If you don't use setuptools, or for some reason haven't installed enmerkar
using setuptools/pip, you'll need to define what function the extraction method
“django” maps to. This is done in an extra section at the top of the
configuration file:
.. code-block:: ini
[extractors]
django = enmerkar.extract:extract_django
The encoding of the templates is assumed to be UTF-8. If you are using a
different encoding, you will need to specify it in the configuration. For
example:
.. code-block:: ini
[django: templates/**.*]
encoding = iso-8859-1
Running the Extraction Process
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Once you've set up the configuration file, the actual extraction is performed
by executing the command-line program pybabel
which is installed alongside
the Babel package:
.. code-block:: bash
$ cd projectdir
$ pybabel extract -F babel.cfg -o mypkg/locale/django.pot .
This creates the PO file template in mypkg/locale/django.pot
.
Creating and Updating Translations Catalogs
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
If you don't already have translation catalogs, you need to create them. This
is done using the pybabel init
command:
.. code-block:: bash
$ pybabel init -D django -i mypkg/locale/django.pot -d mypkg/locale -l en_US
$ pybabel init -D django -i mypkg/locale/django.pot -d mypkg/locale -l de_DE
This should create two files: mypkg/locale/en_US/django.po
and
mypkg/locale/de_DE/django.po
. These files are where you put the actual
translations.
When you modify your Python source files or your templates, you genereally need
to sync the translation catalogs. For that, you first perform a fresh
extraction as described in the previous section, so that the django.pot
file
gets updated.
Then, you run the pybabel update
command to merge the changes into the
translation catalogs:
$ pybabel update -D django -i mypkg/locale/django.pot -d mypkg/locale
This will update all the .po
files found in the mypkg/locale
directory.
Compiling Translations Catalogs
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Finally, you need to compile those .po
files to binary .mo
files. Use the
pybabel compile
command for that:
.. code-block:: bash
$ pybabel compile -D django -d mypkg/locale
Add the --statistics
option to get information about the completeness of your
translations:
.. code-block:: bash
$ pybabel compile -D django -d mypkg/locale --statistics
Using setup.py
^^^^^^^^^^^^^^^^^^
Much of the above process can be automated if you add a setup.py
script to
your project and use the distutils/setuptools commands that come with Babel.
This is described at Distutils/Setuptools Integration
_.
Using the Middleware
To use the enmerkar middleware, add it to the list of MIDDLEWARE_CLASSES
in your
settings module. If you're also using Django's own LocaleMiddleware
to vary
the locale based on user preference, the enmerkar middleware must be inserted
after the Django one:
.. code-block:: python
MIDDLEWARE_CLASSES = (
...
'django.middleware.locale.LocaleMiddleware',
'enmerkar.middleware.LocaleMiddleware',
...
)
This adds a locale
attribute to the request object, which is an instance of
the Babel Locale
class. You can access the locale via request.locale
when
the request object is available, or otherwise use the
django_babel.middleware.get_current_locale()
function to get the current
locale from a thread-local cache.
Using the Template Tags
The template filters provided by enmerkar allow formatting of date/time and
number values in a locale-sensitive manner, providing much more powerful
alternatives to the date
, time
, and floatformat
filters that come with
Django.
To make the template filters/tags available, you need to add enmerkar to
the list of INSTALLED_APPS
in your settings module:
.. code-block:: python
INSTALLED_APPS = (
...
'enmerkar',
...
)
And in every template you want to use the filters, you need to explicitly load
the library:
.. code-block:: django
{% load babel %}
General information on date/time and number formatting can be found at
Date Formatting
_ and Number Formatting
_.
The following filters are made available. The examples assume a locale of
en_US
.
datefmt
^^^^^^^^^^^
Renders a string representation of a date.
- Input:
datetime.date
, datetime.datetime
, or a float/int timestamp - Parameters: the format name or pattern (optional)
Assuming that book.pubdate
returns a datetime.date
or
datetime.datetime
object:
.. code-block:: django
{{ book.pubdate|datefmt:"short" }}
would render: 4/1/07, and
.. code-block:: django
{{ book.pubdate|datefmt:"E, MMM dd yyyy GGG" }}
would render: Sun, Apr 01 2007 AD
datetimefmt
^^^^^^^^^^^^^^^
Renders a string representation of a date and time.
- Input:
datetime.datetime
, or a float/int timestamp - Parameters: the format name or pattern (optional)
Examples:
.. code-block:: django
{{ book.pubdate|datetimefmt:"short" }}
would render: 4/1/07 3:30 PM, and
.. code-block:: django
{{ book.pubdate|datetimefmt:"E, MMM dd yyyy GGG' - 'HH:mm:ss'" }}
would render: Sun, Apr 01 2007 AD - 15:30:00
timefmt
^^^^^^^^^^^
Renders a string representation of a time.
- Input:
datetime.datetime
, datetime.time
, or a float/int timestamp - Parameters: the format name or pattern (optional)
Examples:
.. code-block:: django
{{ book.pubdate|timefmt:"short" }}
would render: 3:30 PM, and
.. code-block:: django
{{ book.pubdate|timefmt:"h 'o''clock' a'" }}
would render: 3 o'clock PM
decimalfmt
^^^^^^^^^^^^^^
Renders a string representation of a decimal number.
- Input: a
Decimal
object, or a float/int/long value - Parameters: the format name or pattern (optional)
Examples:
.. code-block:: django
{{ book.pagecount|decimalfmt }}
would render: 1,234, and
.. code-block:: django
{{ book.pagecount|decimalfmt:"#,##0.00" }}
would render: 1,234.00
currencyfmt
^^^^^^^^^^^^^^^
Renders a number formatted as a currency value.
- Input: a
Decimal
object, or a float/int/long value - Parameters: the currency code
Examples:
.. code-block:: django
{{ book.price|currencyfmt:"USD" }}
would render: $49.90
percentfmt
^^^^^^^^^^^^^^
Renders a string representation of a number as a percentage.
- Input: a
Decimal
object, or a float/int/long value - Parameters: the format name or pattern (optional)
Examples:
Assuming book.rebate
would return 0.15
,
.. code-block:: django
{{ book.rebate|percentfmt }}
would render 15%, and
.. code-block:: django
{{ book.rebate|percentfmt:"#,##0.00%" }}
would render 15.00%.
scientificfmt
^^^^^^^^^^^^^^^^^
Renders a string representation of a number using scientific notation.
- Input: a
Decimal
object, or a float/int/long value - Parameters: none
Examples:
Assuming book.numsold
would return 1.000.000,
.. code-block:: django
{{ book.numsold|scientificfmt }}
would render 10E5.
.. _Babel: http://babel.pocoo.org/
.. _Django: https://www.djangoproject.com/
.. _wrapper scripts: https://docs.djangoproject.com/en/dev/topics/i18n/translation/#localization-how-to-create-language-files
.. _Distutils/Setuptools Integration: http://babel.pocoo.org/en/stable/setup.html
.. _Date Formatting: http://babel.pocoo.org/en/stable/dates.html
.. _Number Formatting: http://babel.pocoo.org/en/stable/numbers.html
.. _Locale: http://babel.pocoo.org/en/stable/api/core.html#babel.core.Locale
Changelog
0.7.1 (2019-12-02)
- compatibility with Django 3.0
- drop support for Python < 3.5, Django < 2.2
0.7.0 (2019-10-21)
0.6.2 (2017-12-18)
- compatibility with Django 2.0 added
0.6.1 (2017-12-18)
- compatibility with Django 1.11 added
0.6.0 - 2017-04-25
- compatibility with unsupported Django versions (<1.8) is dropped
- compatibility with Django 1.10+ middlewares was added
0.5.1 - 2016-03-30
- make imports absolute in babel templatetags
- strip quotes from translations via _()
- fix links in docs
- Add support for "trimmed" blocktrans content
0.5.0 - 2016-02-29
- Add compatibility for Django-1.9
0.4.0 - 2015-04-22
- Add compatibility for Django 1.8
- Add compatibility for latest django master
- Various python 3 fixes
0.3.9 - 2014-12-24
- Fix dependencies on Django/Babel to use lower-case egg names.
0.3.8 - 2014-10-14
- Fix old reference to
babeldjango
module in entry points.
0.3.7 - 2014-10-14
- Fix Python 3.x compatibility in
babel makemessages
command.
0.3.6 - 2014-10-05
0.3.5 - 2014-09-10
- Create .po and .pot files if not existing, plus it's specific base directories.
0.3.4 - 2014-05-25
- Fixed django compatibility
0.3.3 - 2014-04-22
0.3.2 - 2014-04-22
- Initial testing infrastructure
- Add management command
babel
with makemessages
and compilemessages
labels. Mimics django's makemessages
and compilemessages
commands. - Various unicode fixes
0.3.1 - 2013-12-11
- fix relative import in template tags
0.3.0 - 2013-12-11
- Rename package to django_babel
0.2.3 - 2013-12-11
- Rename package on PyPI
- Use GitHub as source control
.. _master
: https://github.com/Zegocover/enmerkar