add I18nField and replace the title JSONField with it

src/c3nav/mapdata/fields.py

@@ -2,11 +2,14 @@ import json
 import logging
 import typing
 
+from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.core.validators import RegexValidator
 from django.db import models
-from django.utils.functional import cached_property
+from django.utils.functional import cached_property, lazy
+from django.utils.text import format_lazy
 from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import get_language
 from shapely import validation
 from shapely.geometry import LineString, MultiPolygon, Point, Polygon, mapping, shape
 from shapely.geometry.base import BaseGeometry
@@ -126,3 +129,67 @@ class JSONField(models.TextField):
     def value_to_string(self, obj):
         value = self.value_from_object(obj)
         return self.get_prep_value(value)
+
+
+def get_i18n_value(i18n_dict, fallback_language, fallback_any, fallback_value):
+    lang = get_language()
+    if i18n_dict:
+        if lang in i18n_dict:
+            return i18n_dict[lang]
+        if fallback_language in i18n_dict:
+            return i18n_dict[fallback_language]
+        if fallback_any:
+            return next(iter(i18n_dict.values()))
+    return str(fallback_value)
+
+
+lazy_get_i18n_value = lazy(get_i18n_value, str)
+
+
+class I18nDescriptor:
+    def __init__(self, field):
+        self.field = field
+
+    def __get__(self, instance, cls=None):
+        if instance is None:
+            return self
+
+        fallback_value = self.field.fallback_value
+        if fallback_value is not None:
+            fallback_value = format_lazy(fallback_value, model_name=instance._meta.verbose_name, pk=instance.pk)
+        return lazy_get_i18n_value(getattr(instance, self.field.attname),
+                                   fallback_language=self.field.fallback_language,
+                                   fallback_any=self.field.fallback_any,
+                                   fallback_value=fallback_value)
+
+
+class I18nField(JSONField):
+    def __init__(self, plural_name=None, fallback_language=settings.LANGUAGE_CODE,
+                 fallback_any=False, fallback_value=None, default=None):
+        self.plural_name = plural_name
+        self.fallback_language = fallback_language
+        self.fallback_any = fallback_any
+        self.fallback_value = fallback_value
+        super().__init__(default=(dict(default) if default else {}), null=False)
+
+    def deconstruct(self):
+        name, path, args, kwargs = super().deconstruct()
+        kwargs = {}
+        if self.default != {}:
+            kwargs['default'] = self.default
+        if self.plural_name is not None:
+            kwargs['plural_name'] = self.plural_name
+        if self.fallback_language != settings.LANGUAGE_CODE:
+            kwargs['fallback_language'] = self.fallback_language
+        if self.fallback_any:
+            kwargs['fallback_any'] = self.fallback_any
+        if self.fallback_value is not None:
+            kwargs['fallback_value'] = self.fallback_value
+        return name, path, args, kwargs
+
+    def contribute_to_class(self, cls, name, *args, **kwargs):
+        super().contribute_to_class(cls, name, *args, **kwargs)
+        setattr(cls, self.name, I18nDescriptor(self))
+
+    def get_attname(self):
+        return self.name+'_i18n' if self.plural_name is None else self.plural_name

src/c3nav/mapdata/migrations/0053_i18nfield.py

@@ -0,0 +1,104 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.6 on 2017-11-29 23:28
+from __future__ import unicode_literals
+
+import c3nav.mapdata.fields
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('mapdata', '0052_auto_20171125_1335'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='accessrestriction',
+            name='titles',
+            field=c3nav.mapdata.fields.I18nField(fallback_any=True, fallback_value='{model_name} {pk}',
+                                                 plural_name='titles'),
+        ),
+        migrations.AlterField(
+            model_name='area',
+            name='titles',
+            field=c3nav.mapdata.fields.I18nField(fallback_any=True, fallback_value='{model_name} {pk}',
+                                                 plural_name='titles'),
+        ),
+        migrations.AlterField(
+            model_name='level',
+            name='titles',
+            field=c3nav.mapdata.fields.I18nField(fallback_any=True, fallback_value='{model_name} {pk}',
+                                                 plural_name='titles'),
+        ),
+        migrations.AlterField(
+            model_name='locationgroup',
+            name='titles',
+            field=c3nav.mapdata.fields.I18nField(fallback_any=True, fallback_value='{model_name} {pk}',
+                                                 plural_name='titles'),
+        ),
+        migrations.AlterField(
+            model_name='locationgroupcategory',
+            name='titles',
+            field=c3nav.mapdata.fields.I18nField(fallback_any=True, fallback_value='{model_name} {pk}',
+                                                 plural_name='titles'),
+        ),
+        migrations.AlterField(
+            model_name='poi',
+            name='titles',
+            field=c3nav.mapdata.fields.I18nField(fallback_any=True, fallback_value='{model_name} {pk}',
+                                                 plural_name='titles'),
+        ),
+        migrations.AlterField(
+            model_name='space',
+            name='titles',
+            field=c3nav.mapdata.fields.I18nField(fallback_any=True, fallback_value='{model_name} {pk}',
+                                                 plural_name='titles'),
+        ),
+        migrations.AlterField(
+            model_name='waytype',
+            name='titles',
+            field=c3nav.mapdata.fields.I18nField(fallback_any=True, fallback_value='{model_name} {pk}',
+                                                 plural_name='titles'),
+        ),
+        migrations.RenameField(
+            model_name='accessrestriction',
+            old_name='titles',
+            new_name='title',
+        ),
+        migrations.RenameField(
+            model_name='area',
+            old_name='titles',
+            new_name='title',
+        ),
+        migrations.RenameField(
+            model_name='level',
+            old_name='titles',
+            new_name='title',
+        ),
+        migrations.RenameField(
+            model_name='locationgroup',
+            old_name='titles',
+            new_name='title',
+        ),
+        migrations.RenameField(
+            model_name='locationgroupcategory',
+            old_name='titles',
+            new_name='title',
+        ),
+        migrations.RenameField(
+            model_name='poi',
+            old_name='titles',
+            new_name='title',
+        ),
+        migrations.RenameField(
+            model_name='space',
+            old_name='titles',
+            new_name='title',
+        ),
+        migrations.RenameField(
+            model_name='waytype',
+            old_name='titles',
+            new_name='title',
+        ),
+    ]

src/c3nav/mapdata/models/base.py

@@ -5,7 +5,7 @@ from django.db import models
 from django.utils.translation import ugettext_lazy as _
 from django.utils.translation import get_language, get_language_info
 
-from c3nav.mapdata.fields import JSONField
+from c3nav.mapdata.fields import I18nField
 from c3nav.mapdata.models import MapUpdate
 
 
@@ -47,7 +47,7 @@ class SerializableMixin(models.Model):
 
 
 class TitledMixin(SerializableMixin, models.Model):
-    titles = JSONField(default={})
+    title = I18nField(plural_name='titles', fallback_any=True, fallback_value='{model_name} {pk}')
 
     class Meta:
         abstract = True
@@ -75,15 +75,6 @@ class TitledMixin(SerializableMixin, models.Model):
             result['display'].append((language, title))
         return result
 
-    @property
-    def title(self):
-        lang = get_language()
-        if self.titles:
-            if lang in self.titles:
-                return self.titles[lang]
-            return next(iter(self.titles.values()))
-        return super().title
-
 
 class BoundsMixin(SerializableMixin, models.Model):
     bottom = models.DecimalField(_('bottom coordinate'), max_digits=6, decimal_places=2)

src/c3nav/mapdata/models/locations.py

@@ -117,12 +117,6 @@ class Location(LocationSlug, AccessRestrictionMixin, TitledMixin, models.Model):
                 return code+':'+str(self.id)
         return self.slug
 
-    @property
-    def title(self):
-        if not self.titles and self.slug:
-            return self._meta.verbose_name + ' ' + self.slug
-        return super().title
-
     @property
     def subtitle(self):
         return ''