Added Subschema.extend method

ldapserver/schema/types.py

@@ -583,6 +583,20 @@ class Subschema(Object):
 		self['matchingRules'] = [matching_rule.encode_syntax_definition() for matching_rule in self.matching_rules.values()]
 		self['attributeTypes'] = [attribute_type.schema_encoding for attribute_type in self.attribute_types.values()]
 
+	def extend(self, *subschemas, dn=None, object_classes=None, attribute_types=None, matching_rules=None, syntaxes=None):
+		if dn is None:
+			dn = self.dn
+		object_classes = list(self.object_classes.values()) + list(object_classes or [])
+		attribute_types = list(self.attribute_types.values()) + list(attribute_types or [])
+		matching_rules = list(self.matching_rules.values()) + list(matching_rules or [])
+		syntaxes = list(self.syntaxes.values()) + list(syntaxes or [])
+		for subschema in subschemas:
+			object_classes += list(subschema.object_classes.values())
+			attribute_types += list(subschema.attribute_types.values())
+			matching_rules += list(subschema.matching_rules.values())
+			syntaxes += list(subschema.syntaxes.values())
+		return Subschema(dn, object_classes, attribute_types, matching_rules, syntaxes)
+
 	def lookup_attribute(self, oid_or_name, fail_if_not_found=False):
 		if isinstance(oid_or_name, AttributeType):
 			if self.attribute_types.get(oid_or_name.oid) != oid_or_name: