Changed handling of supported fields. By default CharField, TextField and subclasses of these fields are supported. Supported fields can be extended through the setting MODELTRANSLATION_CUSTOM_FIELDS. Support for related fields is experimental and these fields explicitly raise a FutureWarning now.

CHANGELOG.txt

@@ -11,6 +11,7 @@
          ManyToManyField and OneToOneField.
          (resolves issue 15)
 
+CHANGED: Custom fields are extended instead of overridden.
 CHANGED: Factored out settings into a separate settings.py and consistently
          used an app specific settings prefix.
 CHANGED: Refactored creation of translation fields and added handling of

docs/modeltranslation/modeltranslation.txt

@@ -303,6 +303,24 @@ the ``django.utils.i18n.get_language`` function to determine the current
 language.
 
 
+Supported fields
+----------------
+``Modeltranslation`` officially supports CharField and TextField.
+
+*New in development version*
+In most cases subclasses of these fields will work fine, too. Other fields
+aren't supported and will throw an ``ImproperlyConfigured`` exception.
+
+The list of supported fields can be extended. Just define a tuple of field names in your settings.py like this::
+
+    MODELTRANSLATION_CUSTOM_FIELDS = ('MyField', 'MyOtherField',)
+
+*Note:* This just prevents ``modeltranslation`` from throwing an
+``ImproperlyConfigured`` exception. Any non text-like field will most likely
+fail in one way or another. The feature is considered experimental and might be
+replaced by a more sophisticated mechanism in future versions.
+
+
 Set a default value
 -------------------
 *New in development version*
@@ -334,8 +352,8 @@ following:
 1. Removes the original field from every admin form by setting it
    ``editable=False``.
 2. Copies the widget of the original field to each of it's translation fields.
-3. Checks if the - now removed - original field was required and if so makes the
-   default translation field required instead.
+3. Checks if the - now removed - original field was required and if so makes
+   the default translation field required instead.
 
 
 TranslationAdmin in combination with other admin classes

modeltranslation/fields.py

@@ -4,7 +4,7 @@ from warnings import warn
 
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
-from django.db.models.fields import Field, CharField
+from django.db.models.fields import Field, CharField, TextField
 from django.db.models.fields.related import (ForeignKey, OneToOneField,
                                              ManyToManyField)
 
@@ -16,20 +16,28 @@ from modeltranslation.utils import (get_language,
 
 def create_translation_field(model, field_name, lang):
     """
-    Translation field factory.
+    Translation field factory. Returns a ``TranslationField`` based on a
+    fieldname and a language.
 
     Tries to create an object in the form  ``'Translation%s' % cls_name``
     (e.g. ``TranslationForeignKey``, ``TranslationManyToManyField``) based on
     ``model`` and ``field_name``. The class is usually a subclass of
-    ``TranslationField`` and is supposed to be implemented in this module. If
-    the class is listed in ``STD_TRANSLATION_FIELDS`` then ``TranslationField``
-    will be used to instantiate the object. If the class is neither implemented
-    nor in ``STD_TRANSLATION_FIELDS`` ``ImproperlyConfigured`` will be raised.
+    ``TranslationField`` and is supposed to be implemented in this module.
+
+    The list of supported fields can be extended. Just define a tuple of field
+    names in your settings.py like this::
+
+        MODELTRANSLATION_CUSTOM_FIELDS = ('MyField', 'MyOtherField',)
+
+    If the class is a subclass of CharField or TextField then the standard
+    ``TranslationField`` will be used to instantiate the object. If the class
+    is neither a subclass of CharField or TextField, nor implemented here, nor
+    in ``CUSTOM_FIELDS`` an ``ImproperlyConfigured`` exception will be raised.
     """
     field = model._meta.get_field(field_name)
     cls_name = field.__class__.__name__
-    # No subclass required for text fields
-    if cls_name in STD_TRANSLATION_FIELDS:
+    # No subclass required for text-like fields
+    if isinstance(field, (CharField, TextField)) or cls_name in CUSTOM_FIELDS:
         return TranslationField(translated_field=field, language=lang)
     # Try to instantiate translation field subclass
     try:
@@ -41,11 +49,11 @@ def create_translation_field(model, field_name, lang):
     # Handle related fields
     if cls_name in ('ForeignKey', 'OneToOneField', 'ManyToManyField'):
         warn('Support for related fields is experimental and known to has '
-             'flaws. Only use it if you know what you are doing.', UserWarning)
-        to = field.rel.to._meta.object_name
-        return translation_field(translated_field=field, language=lang, to=to)
-    # TODO: Should never be reached?
-    return TranslationField(field, lang)
+             'flaws. Only use it if you know what you are doing.',
+             FutureWarning)
+        return translation_field(translated_field=field, language=lang,
+                                 to=field.rel.to._meta.object_name)
+    return TranslationField(translated_field=field, language=lang)
 
 
 class TranslationField(Field):

modeltranslation/settings.py

@@ -26,20 +26,13 @@ if DEFAULT_LANGUAGE and DEFAULT_LANGUAGE not in AVAILABLE_LANGUAGES:
 elif not DEFAULT_LANGUAGE:
     DEFAULT_LANGUAGE = AVAILABLE_LANGUAGES[0]
 
-# Only override this setting if you know what you are doing! It merely exist
-# to test currently unsupported fields.
 # FIXME: We can't seem to override this particular setting in tests.py
-STD_TRANSLATION_FIELDS =\
-getattr(settings, 'MODELTRANSLATION_STD_TRANSLATION_FIELDS',
-        ('CharField', 'TextField', 'URLField', 'EmailField', 'XMLField',))
-#try:
-    #if sys.argv[1] == 'test':
-        #STD_TRANSLATION_FIELDS =\
-        #getattr(settings, 'MODELTRANSLATION_STD_TRANSLATION_FIELDS',
-                #('CharField', 'TextField', 'URLField', 'EmailField',
-                 #'XMLField', 'BooleanField', 'NullBooleanField',
-                 #'IntegerField', 'BigIntegerField', 'PositiveIntegerField',
-                 #'PositiveSmallIntegerField', 'SmallIntegerField',
-                 #'CommaSeparatedIntegerField'))
-#except IndexError:
-    #pass
+CUSTOM_FIELDS =\
+getattr(settings, 'MODELTRANSLATION_CUSTOM_FIELDS', ())
+try:
+    if sys.argv[1] == 'test':
+        CUSTOM_FIELDS =\
+        getattr(settings, 'MODELTRANSLATION_CUSTOM_FIELDS',
+                ('BooleanField',))
+except IndexError:
+    pass

modeltranslation/translator.py

@@ -55,6 +55,9 @@ def add_localized_fields(model):
     for field_name in translation_opts.fields:
         localized_fields[field_name] = list()
         for l in settings.LANGUAGES:
+            # Create a dynamic translation field
+            translation_field = create_translation_field(model=model,\
+                                field_name=field_name, lang=l[0])
             # Construct the name for the localized field
             localized_field_name = build_localized_fieldname(field_name, l[0])
             # Check if the model already has a field by that name
@@ -63,9 +66,6 @@ def add_localized_fields(model):
                                  "already contains a field named '%s'." %\
                                  (instance.__class__.__name__,
                                   localized_field_name))
-            # Create a dynamic translation field
-            translation_field = create_translation_field(model=model,\
-                                field_name=field_name, lang=l[0])
             # This approach implements the translation fields as full valid
             # django model fields and therefore adds them via add_to_class
             localized_field = model.add_to_class(localized_field_name,