--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/modeltranslation/fields.py	Thu Jan 21 18:41:10 2010 +0100
@@ -0,0 +1,98 @@
+    
+from django.conf import settings
+from django.db.models.fields import Field, CharField
+from django.utils.translation import get_language
+
+from modeltranslation.utils import build_localized_fieldname
+
+class TranslationField(Field):
+    """
+    The translation field functions as a proxy to the original field which is
+    wrapped. 
+    
+    For every field defined in the model's ``TranslationOptions`` localized
+    versions of that field are added to the model depending on the languages
+    given in ``settings.LANGUAGES``.
+
+    If for example there is a model ``News`` with a field ``title`` which is
+    registered for translation and the ``settings.LANGUAGES`` contains the
+    ``de`` and ``en`` languages, the fields ``title_de`` and ``title_en`` will
+    be added to the model class. These fields are realized using this 
+    descriptor.
+    
+    The translation field needs to know which language it contains therefore
+    that needs to be specified when the field is created.            
+    """
+    def __init__(self, translated_field, language, *args, **kwargs):
+        # Store the originally wrapped field for later
+        self.translated_field = translated_field
+        self.language = language
+        
+        # Update the dict of this field with the content of the original one
+        # This might be a bit radical?! Seems to work though...
+        self.__dict__.update(translated_field.__dict__)        
+        
+        # Translation are always optional (for now - maybe add some parameters
+        # to the translation options for configuring this)
+        self.null = True
+        self.blank = True
+        
+        # Adjust the name of this field to reflect the language
+        self.attname = build_localized_fieldname(translated_field.name, language)
+        self.name = self.attname
+        
+        # Copy the verbose name and append a language suffix (will e.g. in the
+        # admin). This might be a proxy function so we have to check that here.
+        if hasattr(translated_field.verbose_name, '_proxy____unicode_cast'):            
+            verbose_name = translated_field.verbose_name._proxy____unicode_cast()
+        else:
+            verbose_name = translated_field.verbose_name                       
+        self.verbose_name = '%s [%s]' % (verbose_name, language)
+                
+    def pre_save(self, model_instance, add):              
+        val = super(TranslationField, self).pre_save(model_instance, add)
+        if get_language() == self.language and not add:            
+            # Rule is: 3. Assigning a value to a translation field of the default language
+            #             also updates the original field
+            model_instance.__dict__[self.translated_field.name] = val
+            #setattr(model_instance, self.attname, orig_val)
+            # Also return the original value
+            #return orig_val
+        return val
+                    
+    #def get_attname(self):
+        #return self.attname       
+                
+    def get_internal_type(self):
+        return self.translated_field.get_internal_type()
+        
+    def contribute_to_class(self, cls, name):                      
+        
+        super(TranslationField, self).contribute_to_class(cls, name)
+        
+        #setattr(cls, 'get_%s_display' % self.name, curry(cls._get_FIELD_display, field=self))
+    
+#class CurrentLanguageField(CharField):
+    #def __init__(self, **kwargs):
+        #super(CurrentLanguageField, self).__init__(null=True, max_length=5, **kwargs)
+        
+    #def contribute_to_class(self, cls, name):
+        #super(CurrentLanguageField, self).contribute_to_class(cls, name)
+        #registry = CurrentLanguageFieldRegistry()
+        #registry.add_field(cls, self)
+        
+        
+#class CurrentLanguageFieldRegistry(object):
+    #_registry = {}
+    
+    #def add_field(self, model, field):
+        #reg = self.__class__._registry.setdefault(model, [])
+        #reg.append(field)
+        
+    #def get_fields(self, model):
+        #return self.__class__._registry.get(model, [])
+    
+    #def __contains__(self, model):
+        #return model in self.__class__._registry
+    
+        
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