Make extra sure cache is emptied when objects get altered.

See the (new) cachePerInstance decorator in UM/Decorators, and the accompanying CachedMemberFunction handler-class.

part of CURA-11761

plugins/XmlMaterialProfile/XmlMaterialProfile.py

@@ -11,6 +11,7 @@ import xml.etree.ElementTree as ET
 from UM.PluginRegistry import PluginRegistry
 from UM.Resources import Resources
 from UM.Logger import Logger
+from UM.Decorators import CachedMemberFunctions
 import UM.Dictionary
 from UM.Settings.InstanceContainer import InstanceContainer
 from UM.Settings.ContainerRegistry import ContainerRegistry
@@ -71,6 +72,8 @@ class XmlMaterialProfile(InstanceContainer):
             Logger.log("w", "Can't change metadata {key} of material {material_id} because it's read-only.".format(key = key, material_id = self.getId()))
             return
 
+        CachedMemberFunctions.clearInstanceCache(self)
+
         # Some metadata such as diameter should also be instantiated to be a setting. Go though all values for the
         # "properties" field and apply the new values to SettingInstances as well.
         new_setting_values_dict = {}
@@ -480,6 +483,7 @@ class XmlMaterialProfile(InstanceContainer):
                     first.append(element)
 
     def clearData(self):
+        CachedMemberFunctions.clearInstanceCache(self)
         self._metadata = {
             "id": self.getId(),
             "name": ""
@@ -519,6 +523,8 @@ class XmlMaterialProfile(InstanceContainer):
     def deserialize(self, serialized, file_name = None):
         """Overridden from InstanceContainer"""
 
+        CachedMemberFunctions.clearInstanceCache(self)
+
         containers_to_add = []
         # update the serialized data first
         from UM.Settings.Interfaces import ContainerInterface