Tree parent filtering

- Prevents recursion

InvenTree/InvenTree/models.py

@@ -0,0 +1,83 @@
+from __future__ import unicode_literals
+
+from django.db import models
+from django.core.exceptions import ObjectDoesNotExist
+from django.contrib.contenttypes.models import ContentType
+
+class InvenTreeTree(models.Model):
+    name = models.CharField(max_length=100)
+    description = models.CharField(max_length=250)
+    parent = models.ForeignKey('self',
+                               on_delete=models.CASCADE,
+                               blank=True,
+                               null=True)
+                               #limit_choices_to={id: getAcceptableParents})
+    
+    # Return a flat set of all child items under this node
+    def getUniqueChildren(self, unique=None):
+        
+        if unique is None:
+            unique = set()
+        
+        if self.id in unique:
+            return unique
+        
+        unique.add(self.id)
+            
+        # Some magic to get around the limitations of abstract models
+        contents = ContentType.objects.get_for_model(type(self))
+        children = contents.get_all_objects_for_this_type(parent = self.id)
+        
+        for child in children:
+            child.getUniqueChildren(unique)
+            
+        return unique
+    
+    # Return a list of acceptable other parents
+    def getAcceptableParents(self):
+        contents = ContentType.objects.get_for_model(type(self))
+        
+        available = contents.get_all_objects_for_this_type()
+        
+        # List of child IDs 
+        childs = getUniqueChildren()
+        
+        acceptable = [None]
+        
+        for a in available:
+            if a.id not in childs:
+                acceptable.append(a)
+                
+        return acceptable
+    
+    # Return the parent path of this category
+    @property
+    def path(self):
+        if self.parent:
+            return self.parent.path + [self.parent]
+        else:
+            return []
+        
+        return parent_path
+    
+    # Custom SetAttribute function to prevent parent recursion
+    def __setattr__(self, attrname, val):
+        # Prevent parent from being set such that it would cause a recursion loop
+        if attrname == 'parent_id':
+            # Parent cannot be set to same ID (this would cause looping)
+            if val == self.id:
+                return
+            # Null parent is OK
+            elif val is None:
+                pass
+            # Ensure that the new parent is not already a child 
+            else:
+                kids = self.getUniqueChildren()
+                if val in kids:
+                    print("ALREADY A CHILD")
+                    return
+                
+        super(InvenTreeTree, self).__setattr__(attrname, val)
+    
+    class Meta:
+        abstract = True

InvenTree/InvenTree/settings.py

@@ -38,7 +38,8 @@ INSTALLED_APPS = [
     'django.contrib.messages',
     'django.contrib.staticfiles',
     
-    'part.apps.PartConfig'
+    'part.apps.PartConfig',
+    'stock.apps.StockConfig'
 ]
 
 MIDDLEWARE = [