Method recursivelyCreateSubtree

src/xml_parsing.cpp:1042–1262

}

void BT::XMLParser::PImpl::recursivelyCreateSubtree(
    const std::string& tree_ID, const std::string& tree_path,
    const std::string& prefix_path, Tree& output_tree, Blackboard::Ptr blackboard,
    const TreeNode::Ptr& root_node, std::unordered_set<std::string>& ancestors)
{
  if(!ancestors.insert(tree_ID).second)
  {
    throw RuntimeError("Recursive behavior tree cycle detected: tree '", tree_ID,
                       "' references itself (directly or indirectly)");
  }
  constexpr int kMaxNestingDepth = 256;
  std::function<void(const TreeNode::Ptr&, Tree::Subtree::Ptr, std::string,
                     const XMLElement*, int)>
      recursiveStep;

  recursiveStep = [&](TreeNode::Ptr parent_node, Tree::Subtree::Ptr subtree,
                      std::string prefix, const XMLElement* element, int depth) {
    if(depth > kMaxNestingDepth)
    {
      throw RuntimeError("Maximum XML nesting depth exceeded during tree "
                         "instantiation (limit: ",
                         std::to_string(kMaxNestingDepth),
                         "). The XML is too deeply nested.");
    }
    // create the node
    auto node = createNodeFromXML(element, blackboard, parent_node, prefix, output_tree);
    subtree->nodes.push_back(node);

    // common case: iterate through all children
    if(node->type() != NodeType::SUBTREE)
    {
      for(auto child_element = element->FirstChildElement(); child_element != nullptr;
          child_element = child_element->NextSiblingElement())
      {
        recursiveStep(node, subtree, prefix, child_element, depth + 1);
      }
    }
    else  // special case: SubTreeNode
    {
      auto new_bb = Blackboard::create(blackboard);
      // Inherit polymorphic cast registry from factory (Issue #943)
      new_bb->setPolymorphicCastRegistry(factory->polymorphicCastRegistryPtr());
      const std::string subtree_ID = element->Attribute("ID");
      std::unordered_map<std::string, std::string> subtree_remapping;
      bool do_autoremap = false;

      for(auto attr = element->FirstAttribute(); attr != nullptr; attr = attr->Next())
      {
        const std::string attr_name = attr->Name();
        std::string attr_value = attr->Value();
        if(attr_value == "{=}")
        {
          attr_value = StrCat("{", attr_name, "}");
        }

        if(attr_name == "_autoremap")
        {
          do_autoremap = convertFromString<bool>(attr_value);