Use lazy model evaluation for fixed type constraints

1 files changed, 54 insertions, 0 deletions

diff --git a/ishtar_common/models.py b/ishtar_common/models.py
index 3453a53c5..814387bb4 100644
--- a/ishtar_common/models.py
+++ b/ishtar_common/models.py
@@ -43,6 +43,7 @@ from django.db.utils import DatabaseError
 from django.db.models import Q, Max, Count
 from django.db.models.base import ModelBase
 from django.db.models.signals import post_save, pre_delete, post_delete
+from django.utils.functional import lazy
 from django.utils.translation import ugettext_lazy as _, ugettext, \
     pgettext_lazy
 
@@ -334,6 +335,51 @@ class GeneralType(Cached, models.Model):
         return self.label
 
     @classmethod
+    def get_or_create(cls, slug, label=''):
+        """
+        Get or create a new item.
+
+        :param slug: textual id
+        :param label: label for initialization if the item doesn't exist (not
+        mandatory)
+
+        :return: instancied item of the base class
+        """
+
+        item = cls.get_cache(slug)
+        if item:
+            return item
+        item, created = cls.objects.get_or_create(
+                txt_idx=slug, defaults={'label': label})
+        return item
+
+    @classmethod
+    def get_or_create_pk(cls, slug):
+        """
+        Get an id from a slug. Create the associated item if needed.
+
+        :param slug: textual id
+
+        :return: the id of the item
+        """
+        return cls.get_or_create(slug).pk
+
+    @classmethod
+    def get_or_create_pks(cls, slugs):
+        """
+        Get and merge a list of ids from a slug list. Create the associated
+        items if needed.
+
+        :param slugs: textual ids
+
+        :return: string with ids separated by "_"
+        """
+        items = []
+        for slug in slugs:
+            items.append(str(cls.get_or_create(slug).pk))
+        return "_".join(items)
+
+    @classmethod
     def get_help(cls, dct={}, exclude=[]):
         help_text = cls.HELP_TEXT
         c_rank = -1
@@ -1534,6 +1580,10 @@ class OrganizationType(GeneralType):
 post_save.connect(post_save_cache, sender=OrganizationType)
 post_delete.connect(post_save_cache, sender=OrganizationType)
 
+organization_type_lazy = lazy(OrganizationType.get_or_create, OrganizationType)
+organization_type_pk_lazy = lazy(OrganizationType.get_or_create_pk, int)
+organization_type_pks_lazy = lazy(OrganizationType.get_or_create_pks, unicode)
+
 IMPORTER_CLASSES = {}
 
 IMPORTER_CLASSES.update({
@@ -2324,6 +2374,10 @@ class PersonType(GeneralType):
 post_save.connect(post_save_cache, sender=PersonType)
 post_delete.connect(post_save_cache, sender=PersonType)
 
+person_type_lazy = lazy(PersonType.get_or_create_pk, PersonType)
+person_type_pk_lazy = lazy(PersonType.get_or_create_pk, int)
+person_type_pks_lazy = lazy(PersonType.get_or_create_pks, unicode)
+
 
 class TitleType(GeneralType):
     class Meta: