rewrite loadmap implementation

src/c3nav/mapdata/models/level.py

@@ -1,6 +1,8 @@
 from django.db import models
 from django.utils.translation import ugettext_lazy as _
 
+from c3nav.mapdata.models import Package
+
 
 class Level(models.Model):
     """
@@ -9,20 +11,20 @@ class Level(models.Model):
     name = models.SlugField(_('level name'), primary_key=True, max_length=50,
                             help_text=_('Usually just an integer (e.g. -1, 0, 1, 2)'))
     altitude = models.DecimalField(_('level altitude'), null=True, max_digits=6, decimal_places=2)
-    package = models.ForeignKey('Package', on_delete=models.CASCADE, related_name='levels',
+    package = models.ForeignKey(Package, on_delete=models.CASCADE, related_name='levels',
                                 verbose_name=_('map package'))
 
+    path_regex = r'^levels/'
+
     @classmethod
-    def fromfile(cls, data, package, name):
+    def fromfile(cls, data):
         if 'altitude' not in data:
-            raise ValueError('%s.json: missing altitude.' % name)
+            raise ValueError('missing altitude.')
 
         if not isinstance(data['altitude'], (int, float)):
-            raise ValueError('%s.json: altitude has to be in or float.')
+            raise ValueError('altitude has to be int or float.')
 
         return {
-            'name': name,
-            'package': package,
             'altitude': data['altitude'],
         }