Add functionality to clear registered behavior trees

include/behaviortree_cpp_v3/bt_factory.h

@@ -316,6 +316,11 @@ class BehaviorTreeFactory
   /// registerBehaviorTreeFromFile or registerBehaviorTreeFromText.
   std::vector<std::string> registeredBehaviorTrees() const;
 
+  /**
+   * @brief Clear previously-registered behavior trees.
+   */
+  void clearRegisteredBehaviorTrees();
+
   /**
      * @brief instantiateTreeNode creates an instance of a previously registered TreeNode.
      *

include/behaviortree_cpp_v3/bt_parser.h

@@ -40,6 +40,8 @@ class Parser
 
   virtual Tree instantiateTree(const Blackboard::Ptr& root_blackboard,
                                std::string tree_name = {}) = 0;
+
+  virtual void clearInternalState() {};
 };
 
 }   // namespace BT

include/behaviortree_cpp_v3/xml_parsing.h

@@ -31,6 +31,8 @@ class XMLParser : public Parser
   Tree instantiateTree(const Blackboard::Ptr& root_blackboard,
                        std::string main_tree_to_execute = {}) override;
 
+  void clearInternalState() override;
+
 private:
   struct Pimpl;
   Pimpl* _p;

src/bt_factory.cpp

@@ -227,14 +227,19 @@ void BehaviorTreeFactory::registerBehaviorTreeFromFile(const std::string& filena
 
 void BehaviorTreeFactory::registerBehaviorTreeFromText(const std::string& xml_text)
 {
-  parser_->loadFromText(xml_text);
+  parser_->loadFromText(xml_text, true /* add_includes */);
 }
 
 std::vector<std::string> BehaviorTreeFactory::registeredBehaviorTrees() const
 {
   return parser_->registeredBehaviorTrees();
 }
 
+void BehaviorTreeFactory::clearRegisteredBehaviorTrees()
+{
+    parser_->clearInternalState();
+}
+
 std::unique_ptr<TreeNode> BehaviorTreeFactory::instantiateTreeNode(
     const std::string& name, const std::string& ID, const NodeConfiguration& config) const
 {

src/xml_parsing.cpp

@@ -484,6 +484,11 @@ Tree XMLParser::instantiateTree(const Blackboard::Ptr& root_blackboard,
   return output_tree;
 }
 
+void XMLParser::clearInternalState()
+{
+    _p->clear();
+}
+
 TreeNode::Ptr XMLParser::Pimpl::createNodeFromXML(const XMLElement* element,
                                                   const Blackboard::Ptr& blackboard,
                                                   const TreeNode::Ptr& node_parent)

tests/gtest_factory.cpp

@@ -407,3 +407,49 @@ TEST(BehaviorTreeFactory, DecoratorWithTwoChildrenThrows)
 
   ASSERT_THROW(factory.createTreeFromText(xml_text), BehaviorTreeException);
 }
+
+TEST(BehaviorTreeFactory, ParserClearRegisteredBehaviorTrees)
+{
+  const std::string tree_xml = R"(
+<root>
+    <BehaviorTree ID="Main">
+        <AlwaysSuccess />
+    </BehaviorTree>
+</root>
+)";
+
+  BehaviorTreeFactory factory;
+  XMLParser parser(factory);
+
+  ASSERT_NO_THROW(parser.loadFromText(tree_xml));
+
+  const auto trees = parser.registeredBehaviorTrees();
+  ASSERT_FALSE(trees.empty());
+
+  parser.clearInternalState();
+
+  const auto trees_after_clear = parser.registeredBehaviorTrees();
+  EXPECT_TRUE(trees_after_clear.empty());
+}
+
+TEST(BehaviorTreeFactory, FactoryClearRegisteredBehaviorTrees)
+{
+  BehaviorTreeFactory factory;
+  const std::string tree_xml = R"(
+<root>
+    <BehaviorTree ID="Main">
+        <AlwaysSuccess />
+    </BehaviorTree>
+</root>
+)";
+
+  ASSERT_NO_THROW(factory.registerBehaviorTreeFromText(tree_xml));
+
+  const auto trees = factory.registeredBehaviorTrees();
+  ASSERT_FALSE(trees.empty());
+
+  factory.clearRegisteredBehaviorTrees();
+
+  const auto trees_after_clear = factory.registeredBehaviorTrees();
+  EXPECT_TRUE(trees_after_clear.empty());
+}