Added setting to override the default language. Resolves issue 2.

CHANGELOG.txt

@@ -1,3 +1,5 @@
+  ADDED: Setting to override the default language.
+         (thanks to jaap, resolves issue 2)
   ADDED: Support for related fields - ForeignKey, ManyToManyField and
          OneToOneField.
          (resolves issue 15)

docs/modeltranslation/modeltranslation.txt

@@ -96,8 +96,17 @@ modeltranslation app, but rather required for Django to be able to
 (statically) translate the verbose names of the languages using the standard
 ``i18n`` solution.
 
+**settings.MODELTRANSLATION_DEFAULT_LANGUAGE**
+
+*New in development version*
+To override the default language as described in settings.LANGUAGES, define
+``MODELTRANSLATION_DEFAULT_LANGUAGE``. Note that the value has to be in
+settings.LANGUAGES, otherwise an exception will be raised.
+
 **settings.TRANSLATION_REGISTRY**
 
+TODO: Rename setting to MODELTRANSLATION_TRANSLATION_REGISTRY.
+
 In order to be able to import the project's ``translation.py`` registration
 file the ``TRANSLATION_REGISTRY`` must be set to a value in the form
 ``<PROJECT_MODULE>.translation``. E.g. if your project is located in a folder
@@ -366,7 +375,7 @@ custom admin class and that's done in the example above. After that the
 
 Inlines
 -------
-*New in development version*
+*New in 0.2*
 Support for tabular and stacked inlines, common and generic ones.
 
 A translated inline must derive from one of the following classes:

modeltranslation/models.py

@@ -13,6 +13,7 @@ from modeltranslation.translator import translator
 
 # Import the project's global "translation.py" which registers model
 # classes and their translation options with the translator object.
+# TODO: Rename setting to MODELTRANSLATION_TRANSLATION_REGISTRY.
 if getattr(settings, 'TRANSLATION_REGISTRY', False):
     try:
         __import__(settings.TRANSLATION_REGISTRY, {}, {}, [''])

modeltranslation/utils.py

@@ -1,19 +1,24 @@
 # -*- coding: utf-8 -*-
 from django.db import models
 from django.conf import settings
-from django.core.exceptions import ValidationError
+from django.core.exceptions import ValidationError, ImproperlyConfigured
 from django.contrib.contenttypes.models import ContentType
 from django.utils.translation import get_language as _get_language
 from django.utils.functional import lazy
 
 
+def get_available_languages():
+    """Returns a list of the language codes in settings.LANGUAGES"""
+    return [l[0] for l in settings.LANGUAGES]
+
+
 def get_language():
     """
     Return an active language code that is guaranteed to be in
     settings.LANGUAGES (Django does not seem to guarantee this for us.)
     """
     lang = _get_language()
-    available_languages = [l[0] for l in settings.LANGUAGES]
+    available_languages = get_available_languages()
     if lang not in available_languages and '-' in lang:
         lang = lang.split('-')[0]
     if lang in available_languages:
@@ -22,12 +27,26 @@ def get_language():
 
 
 def get_default_language():
-    return settings.LANGUAGES[0][0]
+    """
+    Returns the language to use as the default language. This is either
+    the value of settings.DEFAULT_LANGUAGE (if it's in the list of
+    settings.LANGUAGES) or the first item in settings.LANGUAGES.
+    """
+    available_languages = get_available_languages()
+    default_language = getattr(settings,
+                               'MODELTRANSLATION_DEFAULT_LANGUAGE', None)
+    if default_language and default_language not in available_languages:
+        raise ImproperlyConfigured('MODELTRANSLATION_DEFAULT_LANGUAGE not '
+                                   'in LANGUAGES setting.')
+    if not default_language:
+        default_language = available_languages[0]
+    return default_language
 
 
 def get_translation_fields(field):
     """Returns a list of localized fieldnames for a given field."""
-    return [build_localized_fieldname(field, l[0]) for l in settings.LANGUAGES]
+    return [build_localized_fieldname(field, l) for l in\
+            get_available_languages()]
 
 
 def build_localized_fieldname(field_name, lang):