App: migrate old SubElements in Link

src/App/Link.cpp

@@ -44,7 +44,7 @@ using namespace Base;
 EXTENSION_PROPERTY_SOURCE(App::LinkBaseExtension, App::DocumentObjectExtension)
 
 LinkBaseExtension::LinkBaseExtension(void)
-    :enableLabelCache(false),myOwner(0)
+    :myOwner(0),enableLabelCache(false),hasOldSubElement(false)
 {
     initExtensionType(LinkBaseExtension::getExtensionClassTypeId());
     EXTENSION_ADD_PROPERTY_TYPE(_LinkTouched, (false), " Link", 
@@ -1076,12 +1076,57 @@ void LinkBaseExtension::syncElementList() {
 
 void LinkBaseExtension::onExtendedDocumentRestored() {
     inherited::onExtendedDocumentRestored();
-    auto parent = getContainer();
     myHiddenElements.clear();
-    if(parent) {
-        update(parent,getVisibilityListProperty());
-        update(parent,getLinkedObjectProperty());
-        update(parent,getElementListProperty());
+    auto parent = getContainer();
+    if(!parent)
+        return;
+    if(hasOldSubElement) {
+        hasOldSubElement = false;
+        // SubElements was stored as a PropertyStringList. It is now migrated to be
+        // stored inside PropertyXLink.
+        auto xlink = freecad_dynamic_cast<PropertyXLink>(getLinkedObjectProperty());
+        if(!xlink) 
+            FC_ERR("Failed to restore SubElements for " << parent->getFullName());
+        else if(!xlink->getValue())
+            FC_ERR("Discard SubElements of " << parent->getFullName() << " due to null link");
+        else if(xlink->getSubValues().size() > 1)
+            FC_ERR("Failed to restore SubElements for " << parent->getFullName() 
+                    << " due to conflict subnames");
+        else if(xlink->getSubValues().empty()) {
+            auto subs = xlink->getSubValues();
+            xlink->setSubValues(std::move(subs));
+        } else {
+            std::set<std::string> subset(mySubElements.begin(),mySubElements.end());
+            auto sub = xlink->getSubValues().front();
+            auto element = Data::ComplexGeoData::findElementName(sub.c_str());
+            if(element && element[0]) {
+                subset.insert(element);
+                sub.resize(element - sub.c_str());
+            }
+            std::vector<std::string> subs;
+            for(auto &s : subset)
+                subs.push_back(sub + s);
+            xlink->setSubValues(std::move(subs));
+        }
+    }
+    update(parent,getVisibilityListProperty());
+    update(parent,getLinkedObjectProperty());
+    update(parent,getElementListProperty());
+}
+
+void LinkBaseExtension::_handleChangedPropertyName(
+        Base::XMLReader &reader, const char * TypeName, const char *PropName)
+{
+    if(strcmp(PropName,"SubElements")==0
+        && strcmp(TypeName,PropertyStringList::getClassTypeId().getName())==0)
+    {
+        PropertyStringList prop;
+        prop.setContainer(getContainer());
+        prop.Restore(reader);
+        if(prop.getSize()) {
+            mySubElements = prop.getValues();
+            hasOldSubElement = true;
+        }
     }
 }
 

src/App/Link.h

@@ -204,7 +204,7 @@ public:
         return static_cast<LINK_PPTYPE(_param) *>(prop);\
     }\
 
-    // defines get##Name() and get##Name##Property() accessor
+    // defines get##Name##Property() and get##Name##Value() accessor
     BOOST_PP_SEQ_FOR_EACH(LINK_PROP_GET,_,LINK_PARAMS)
 
     PropertyLinkList *_getElementListProperty() const;
@@ -284,6 +284,8 @@ public:
     void cacheChildLabel(int enable=-1) const;
 
 protected:
+    void _handleChangedPropertyName(Base::XMLReader &reader, 
+            const char * TypeName, const char *PropName);
     void parseSubName() const;
     void update(App::DocumentObject *parent, const Property *prop);
     void syncElementList();
@@ -302,10 +304,12 @@ protected:
     std::unordered_map<const App::DocumentObject*, 
         boost::signals2::scoped_connection> plainGroupConns;
 
+    long myOwner;
+
     mutable std::unordered_map<std::string,int> myLabelCache; // for label based subname lookup
     mutable bool enableLabelCache;
 
-    long myOwner;
+    bool hasOldSubElement;
 };
 
 ///////////////////////////////////////////////////////////////////////////
@@ -452,6 +456,12 @@ public:
         inherited::onDocumentRestored();
     }
 
+    void handleChangedPropertyName(Base::XMLReader &reader, 
+            const char * TypeName, const char *PropName) override
+    {
+        _handleChangedPropertyName(reader,TypeName,PropName);
+    }
+
     bool canLinkProperties() const override;
 };
 
@@ -485,6 +495,12 @@ public:
     }
 
     bool canDelete() const;
+
+    void handleChangedPropertyName(Base::XMLReader &reader, 
+            const char * TypeName, const char *PropName) override
+    {
+        _handleChangedPropertyName(reader,TypeName,PropName);
+    }
 };
 
 typedef App::FeaturePythonT<LinkElement> LinkElementPython;