Enable pre save hook

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/checkouts/apps.py

@@ -22,6 +22,7 @@ from .events import (
     event_document_check_out, event_document_forceful_check_in
 )
 from .handlers import handler_check_new_version_creation
+from .hooks import hook_is_new_version_allowed
 from .links import (
     link_document_check_in, link_document_checkout, link_document_checkout_info,
     link_document_checkout_list, link_document_multiple_check_in,
@@ -70,6 +71,10 @@ class CheckoutsApp(MayanAppConfig):
             name='is_checked_out', value=method_is_checked_out
         )
 
+        DocumentVersion.register_pre_save_hook(
+            func=hook_is_new_version_allowed
+        )
+
         ModelEventType.register(
             model=Document, event_types=(
                 event_document_auto_check_in, event_document_check_in,

mayan/apps/checkouts/hooks.py

@@ -9,5 +9,5 @@ def hook_is_new_version_allowed(document_version):
     )
 
     NewVersionBlock.objects.new_versions_allowed(
-        document_version=document_version.document
+        document=document_version.document
     )

mayan/apps/checkouts/managers.py

@@ -118,7 +118,7 @@ class NewVersionBlockManager(models.Manager):
         return self.filter(document=document).exists()
 
     def new_versions_allowed(self, document):
-        if self.filter(document=document).exist():
+        if self.filter(document=document).exists():
             raise NewDocumentVersionNotAllowed
 
     def unblock(self, document):