Django Country Context

This module solves a small problem that can be found in many sites, where the website has to support multiple countries, e.g. e-commerce website with different stores for different countries, this module allows the developer to define a context per thread, this context holds all the information about the currently available country, and allows the developer to rely on the context always to get the current country instead of passing it through the different levels of code. This module is thread-safe, it defines a different context for each thread.

Using The Context

To use the country context

1. You activate the country of choice when you start to process the request, one place for activating the country is by writing a Django middleware that activates the country in the process_request method.
2. After that your code should depend on the country_context.get_current_country_code to get the current country code, and that should be everywhere, so that you don’t have to pass the current country from the view to the controllers and to other parts of your code.
3. In the end when you finish processing the request you should deactivate the country, also you can do that in the middleware in the process_response method.

If you want to create a middleware you can extend the CountryContextMiddleware included with this package.

Settings

You should have the following two variables:

1. DEFAULT_COUNTRY: The default country code that will be the active country by default.
2. ENABLED_COUNTRIES: A list of country codes that are enabled for your site. Codes are in ISO 3166-1 Alpha 2 format.

Example Usage

We will imagine a Django site, an e-commerce site that serves multiple stores in US and UK, by default it’ll be serving the US site, but if the URL was prefixed with UK then the site will serve the UK store.

# site/settings.py
# ...
DEFAULT_COUNTRY = 'US'
ENABLED_COUNTRIES = ['US', 'UK']
# ...
MIDDLEWARE_CLASSES = (
  # ...
  'site.country_context_middleware.SiteCountryContextMiddleware',
  # ...
)

# site/country_context_middleware.py
import re

from django_country_context.country_context_middleware import CountryContextMiddleware


class SiteCountryContextMiddleware(CountryContextMiddleware):
  def get_country_code_from_request(self, request):
    if re.match(r'^/UK/', request.path_info, re.I):
      return 'UK'
    return 'US'

# site/urls.py

from django.contrib import admin
from django.conf import settings
from django.conf.urls import patterns, include, url

urlpatterns = patterns('',
  url(r'^(?:%s)?/' % '|'.join(
    ''.join(
      '[%s%s]' % (c.upper(), c.lower()) for c in country
    ) for country in settings.ENABLED_COUNTRIES
  ), include('app.urls')),
)

# app/models.py

from django.db import models
from django_country_context import country_context, countries_data


class StoreManager(models.Manager):
  def __init__(self, countries_enabled=True):
    super(StoreManager, self).__init__()
    self.countries_enabled = countries_enabled

  def get_query_set(self):
    qs = super(StoreManager, self).get_query_set()
    if self.countries_enabled:
      qs = qs.filter(country=country_context.get_current_country_code())
    return qs


class Store(models.Model):
  # ...
  country = models.CharField(max_length=2, default=country_context.get_current_country_code, choices=countries_data.ENABLED_COUNTRIES_TUPLE, db_index=True)

  objects = StoreManager()
  objects_no_countries = StoreManager(countries_enabled=False)

# app/admin.py

from django.contrib import admin
from models import Store


class StoreAdmin(admin.ModelAdmin):
  model = Store
  def queryset(self, request):
    self.model._default_manager = self.model.objects_no_countries
    return super(StoreAdmin, self).queryset(request)
  # ...

admin.site.register(Store, StoreAdmin)

Using the setup above will allow the views to call the query the Store model without handling special cases for countries, and you can change the logic of getting the current country without any change to your views, this way we’ve separated the country context completely from the logic of the site. And when you need to get the current country name or code you can use country_context.get_current_country_name() and country_context.get_current_country_code() respectively. Please note that the setup above was written for a Django 1.4.x.

Download

Django Country Context on source code on GitHub