Load models by calling AppConfig.get_model method instead.

mayan/apps/document_states/apps.py

@@ -12,10 +12,6 @@ from documents.models import Document
 from navigation import SourceColumn
 
 from .handlers import launch_workflow
-from .models import (
-    Workflow, WorkflowInstance, WorkflowInstanceLogEntry, WorkflowState,
-    WorkflowTransition
-)
 from .links import (
     link_document_workflow_instance_list, link_setup_workflow_document_types,
     link_setup_workflow_create, link_setup_workflow_delete,
@@ -37,6 +33,12 @@ class DocumentStatesApp(MayanAppConfig):
     def ready(self):
         super(DocumentStatesApp, self).ready()
 
+        Workflow = self.get_model('Workflow')
+        WorkflowInstance = self.get_model('WorkflowInstance')
+        WorkflowInstanceLogEntry = self.get_model('WorkflowInstanceLogEntry')
+        WorkflowState = self.get_model('WorkflowState')
+        WorkflowTransition = self.get_model('WorkflowTransition')
+
         SourceColumn(
             source=Workflow, label=_('Initial state'),
             func=lambda context: context['object'].get_initial_state() or _('None')