void Controller::updateFromXMLNode(SimTK::Xml::Element& node,
                                   int versionNumber) {
    if(versionNumber < XMLDocument::getLatestVersion()) {
        if(versionNumber < 30509) {
            // Rename property 'isDisabled' to 'enabled' and
            // negate the contained value.
            std::string oldName{"isDisabled"};
            std::string newName{"enabled"};
            if(node.hasElement(oldName)) {
                auto elem = node.getRequiredElement(oldName);
                bool isDisabled = false;
                elem.getValue().tryConvertToBool(isDisabled);

                // now update tag name to 'enabled'
                elem.setElementTag(newName);
                // update its value to be the opposite of 'isDisabled'
                elem.setValue(SimTK::String(!isDisabled));
            }
        }
    }

    Super::updateFromXMLNode(node, versionNumber);
}
void Joint::updateFromXMLNode(SimTK::Xml::Element& aNode, int versionNumber)
{
    int documentVersion = versionNumber;
    //bool converting = false;
    if (documentVersion < XMLDocument::getLatestVersion()){
        if (documentVersion<30500){
            XMLDocument::renameChildNode(aNode, "location", "location_in_child"); 
            XMLDocument::renameChildNode(aNode, "orientation", "orientation_in_child");
        }
        // Version 30501 converted Connector_Body_ to Connector_PhysicalFrame_
        if (documentVersion < 30501) {
            // Handle any models that have the Joint connecting to Bodies instead
            // of PhyscialFrames
            XMLDocument::renameChildNode(aNode, "Connector_Body_",
                                                "Connector_PhysicalFrame_");
        }
        // Version 30505 changed "parent_body" connector name to "parent_frame"
        // Convert location and orientation into PhysicalOffsetFrames owned by the Joint
        if (documentVersion < 30505) {
            // Elements for the parent and child names the joint connects
            SimTK::Xml::element_iterator parentNameElt;
            SimTK::Xml::element_iterator childNameElt;
            // The names of the two PhysicalFrames this joint connects
            std::string parentFrameName("");
            std::string childFrameName("");

            SimTK::Xml::element_iterator connectors_node = aNode.element_begin("connectors");

            SimTK::Xml::element_iterator connectorElement =
                connectors_node->element_begin("Connector_PhysicalFrame_");
            while (connectorElement != aNode.element_end()) {
                // If connector name is "parent_body" rename it to "parent_frame"
                if (connectorElement->getRequiredAttributeValue("name") == "parent_body") {
                    connectorElement->setAttributeValue("name", "parent_frame");
                }
                // If connector name is "parent_frame" get the name of the connectee
                if (connectorElement->getRequiredAttributeValue("name") == "parent_frame"){
                    parentNameElt = connectorElement->element_begin("connectee_name");
                    parentNameElt->getValueAs<std::string>(parentFrameName);

                    const auto slashLoc = parentFrameName.rfind('/');
                    if (slashLoc != std::string::npos)
                        parentFrameName = parentFrameName.substr(slashLoc + 1);
                }
                if (connectorElement->getRequiredAttributeValue("name") == "child_body") {
                    connectorElement->setAttributeValue("name", "child_frame");
                }
                if (connectorElement->getRequiredAttributeValue("name") == "child_frame") {
                    childNameElt =  connectorElement->element_begin("connectee_name");
                    childNameElt->getValueAs<std::string>(childFrameName);
                    const auto slashLoc = childFrameName.rfind('/');
                    if (slashLoc != std::string::npos)
                        childFrameName = childFrameName.substr(slashLoc + 1);
                }
                ++connectorElement;
            }

            SimTK::Xml::element_iterator locParentElt =
                aNode.element_begin("location_in_parent");
            SimTK::Xml::element_iterator orientParentElt =
                aNode.element_begin("orientation_in_parent");
            SimTK::Xml::element_iterator locChildElt =
                aNode.element_begin("location_in_child");
            SimTK::Xml::element_iterator orientChildElt =
                aNode.element_begin("orientation_in_child");

            Vec3 location_in_parent(0);
            Vec3 orientation_in_parent(0);
            Vec3 location_in_child(0);
            Vec3 orientation_in_child(0);

            if (locParentElt != aNode.element_end()){
                locParentElt->getValueAs<Vec3>(location_in_parent);
            }
            if (orientParentElt != aNode.element_end()){
                orientParentElt->getValueAs<Vec3>(orientation_in_parent);
            }
            if (locChildElt != aNode.element_end()){
                locChildElt->getValueAs<Vec3>(location_in_child);
            }
            if (orientChildElt != aNode.element_end()){
                orientChildElt->getValueAs<Vec3>(orientation_in_child);
            }

            // now append updated frames to the property list for
            // both parent and child
            XMLDocument::addPhysicalOffsetFrame30505_30517(aNode, parentFrameName+"_offset",
                parentFrameName, location_in_parent, orientation_in_parent);
            parentNameElt->setValue(parentFrameName + "_offset");

            XMLDocument::addPhysicalOffsetFrame30505_30517(aNode, childFrameName + "_offset",
                childFrameName, location_in_child, orientation_in_child);
            childNameElt->setValue(childFrameName + "_offset");
        }

        // Version 30507 replaced Joint's CoordinateSet with a "coordinates"
        // list property.
        if (documentVersion < 30507) {
            if (aNode.hasElement("CoordinateSet")) {
                auto coordSetIter = aNode.element_begin("CoordinateSet");
                if (coordSetIter->hasElement("objects")) {
                    auto coordIter = coordSetIter->getRequiredElement("objects")
                                                   .element_begin("Coordinate");
                    if (coordIter != aNode.element_end()) {
                        // A "CoordinateSet" element exists, it contains an
                        // "objects" element, and the "objects" element contains
                        // at least one "Coordinate" element.

                        // Create an element for the new layout.
                        Xml::Element coordinatesElement("coordinates");
                        // Copy all "Coordinate" elements from the old layout.
                        while (coordIter != aNode.element_end()) {
                            coordinatesElement.appendNode(coordIter->clone());
                            ++coordIter;
                        }
                        // Insert new "coordinates" element.
                        aNode.insertNodeAfter(coordSetIter, coordinatesElement);
                    }
                }

                // Remove old "CoordinateSet" element.
                aNode.eraseNode(coordSetIter);
            }
        }

        // Version 30514 removed the user-facing "reverse" property from Joint.
        // The parent and child frames are swapped if a "reverse" element is
        // found and its value is "true".
        if (documentVersion < 30514) {
            auto reverseElt = aNode.element_begin("reverse");

            if (reverseElt != aNode.element_end()) {
                bool swapFrames = false;
                reverseElt->getValue().tryConvertToBool(swapFrames);

                if (swapFrames) {
                    std::string oldParentFrameName = "";
                    std::string oldChildFrameName  = "";

                    // Find names of parent and child frames. If more than one
                    // "parent_frame" or "child_frame" element exists, keep the
                    // first one. The "parent_frame" and "child_frame" elements
                    // may be listed in either order.
                    SimTK::Xml::element_iterator connectorsNode =
                        aNode.element_begin("connectors");
                    SimTK::Xml::element_iterator connectorElt = connectorsNode->
                        element_begin("Connector_PhysicalFrame_");
                    SimTK::Xml::element_iterator connecteeNameElt;

                    while (connectorElt != connectorsNode->element_end())
                    {
                        if (connectorElt->getRequiredAttributeValue("name") ==
                            "parent_frame" && oldParentFrameName.empty())
                        {
                            connecteeNameElt = connectorElt->
                                               element_begin("connectee_name");
                            connecteeNameElt->getValueAs<std::string>(
                                oldParentFrameName);
                        }
                        else if (connectorElt->getRequiredAttributeValue("name")
                                 == "child_frame" && oldChildFrameName.empty())
                        {
                            connecteeNameElt = connectorElt->
                                               element_begin("connectee_name");
                            connecteeNameElt->getValueAs<std::string>(
                                oldChildFrameName);
                        }
                        ++connectorElt;
                    }

                    // Swap parent and child frame names. If more than one
                    // "parent_frame" or "child_frame" element exists, assign
                    // the same value to all such elements.
                    connectorsNode = aNode.element_begin("connectors");
                    connectorElt = connectorsNode->element_begin(
                                   "Connector_PhysicalFrame_");

                    while (connectorElt != connectorsNode->element_end())
                    {
                        if (connectorElt->getRequiredAttributeValue("name") ==
                            "parent_frame")
                        {
                            connecteeNameElt = connectorElt->
                                               element_begin("connectee_name");
                            connecteeNameElt->setValue(oldChildFrameName);
                        }
                        else if (connectorElt->getRequiredAttributeValue("name")
                                 == "child_frame")
                        {
                            connecteeNameElt = connectorElt->
                                               element_begin("connectee_name");
                            connecteeNameElt->setValue(oldParentFrameName);
                        }
                        ++connectorElt;
                    }
                }

                // Remove "reverse" element regardless of its value (it is no
                // longer a property of Joint).
                aNode.eraseNode(reverseElt);
            }
        }

    }

    Super::updateFromXMLNode(aNode, versionNumber);
}