django-keyed-urls

An app for those cases when you need language-specific URLs in the database for use in templates or as redirects.

Installation

Install django-keyed-urls with pip:

pip install django-keyed-urls

Add keyed_urls and modeltranslation to INSTALLED_APPS.

Specify a custom location for South migrations for keyed_urls -- you really want to use South to handle schema changes when adding or removing languages from LANGUAGES:

SOUTH_MIGRATION_MODULES = {
    'keyed_urls': 'yourapp.migrate.keyed_urls',
}

Create and run database migrations:

python manage.py schemamigration keyed_urls --initial
python manage.py migrate keyed_urls

If you want to use the forwarding URLs, add an entry to your URLconf file. It is recommended to use i18n_patterns because that means that language-specific redirection URLs are automatically handled correctly:

from django.conf.urls import include, url
from django.conf.urls.i18n import i18n_patterns

urlpatterns += i18n_patterns(
    '',
    url(r'', include('keyed_urls.urls'),
)

Usage

Template tags

Usage is simple:

{% load keyed_urls %}

{% keyed_url 'some_key' as url %}

<a href="{{ url }}">bla</a>

<a href="{% keyed_url 'some_other_key' %}">bla</a>

Or:

{% load keyed_urls %}

{% keyed_url 'some_key' language='en' as url %}

<a href="{{ url }}">bla</a>

If a key does not exist and the tag is used as an assignment tag, the variable is set to None. Otherwise, a KeyDoesNotExist exception is raised which also aborts template rendering. The behavior is equal to the behavior of Django's own {% url %} template tag in this regard.

Helpers

Two additional helpers are available. If you need URLs in python code, use the following snippet:

from keyed_urls import get_url

some_url = get_url('some_key')
some_other_url = get_url('some_key', language='en')

The advantage of using get_url compared to fetching a KeyedURL model from the database and accessing its url attribute is that get_url is caching all results. Since get_url is also used internally by the template tag described above this means that you do not have to worry about performance as much as when using models directly. get_url raises a KeyDoesNotExist exception if a particular URL cannot be found. This can be prevented by passing fail_silently=True.

The following snippet can be used to fetch the forwarding URL:

from keyed_urls import get_forwarding_url

url = get_forwarding_url('some_key')
url = get_forwarding_url('some_key', language='de')

get_forwarding_url is nothing more but a thin wrapper around Django's own reverse method. This method raises a NoReverseMatch exception if the key is invalid, but does not check whether the given key exists at all in the database. When visiting the link, users will get a 404 response. For get_forwarding_url to work you have to include keyed_urls.urls somewhere in your URLconf as described above, preferrably inside an i18n_patterns block.