I18nModelFormMixin

src/c3nav/mapdata/forms.py

@@ -0,0 +1,63 @@
+from collections import OrderedDict
+
+from django.conf import settings
+from django.core.exceptions import ValidationError
+from django.forms import CharField, ModelForm
+from django.utils.text import format_lazy
+from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import get_language_info
+
+from c3nav.mapdata.fields import I18nField
+
+
+class I18nModelFormMixin(ModelForm):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        new_fields = OrderedDict()
+        self.i18n_fields = []
+        for name, form_field in self.fields.items():
+            model_field = self.instance._meta.get_field(name)
+
+            if not isinstance(model_field, I18nField):
+                new_fields[name] = form_field
+                continue
+
+            values = OrderedDict((lang_code, '') for lang_code, language in settings.LANGUAGES)
+            if self.instance is not None and self.instance.pk:
+                values.update(getattr(self.instance, model_field.attname))
+
+            has_values = False
+            for language in values.keys():
+                sub_field_name = '%s__%s' % (name, language)
+                new_value = self.data.get(sub_field_name)
+                if new_value is not None:
+                    has_values = True
+                    values[language] = new_value
+                language_info = get_language_info(language)
+                field_title = format_lazy(_('{field_name} ({lang})'),
+                                          field_name=model_field.verbose_name,
+                                          lang=language_info['name_translated'])
+                new_fields[sub_field_name] = CharField(label=field_title,
+                                                       required=False,
+                                                       initial=values[language].strip(),
+                                                       max_length=model_field.i18n_max_length)
+
+            if has_values:
+                self.i18n_fields.append((model_field, values))
+
+        self.fields = new_fields
+
+    def clean(self):
+        for field, values in self.i18n_fields:
+            if not field.blank and not any(values.values()):
+                raise ValidationError(_('You have to choose a value for {field} in at least one language.').format(
+                    field=field.verbose_name
+                ))
+
+        super().clean()
+
+    def full_clean(self):
+        super().full_clean()
+        for field, values in self.i18n_fields:
+            setattr(self.instance, field.attname, {lang: value for lang, value in values.items() if value})