Expose get_node_names API from node. (#508)

* Exposing get_node_names from node handle

Signed-off-by: Sriram Raghunathan <rsriram7@visteon.com>

* Exposing get_node_names from node handle for lifecycle_nodes

Signed-off-by: Sriram Raghunathan <rsriram7@visteon.com>

* Fix stray demangle type

rclcpp/include/rclcpp/node.hpp

@@ -341,6 +341,10 @@ public:
   void
   register_param_change_callback(CallbackT && callback);
 
+  RCLCPP_PUBLIC
+  std::vector<std::string>
+  get_node_names() const;
+
   RCLCPP_PUBLIC
   std::map<std::string, std::vector<std::string>>
   get_topic_names_and_types() const;

rclcpp/src/rclcpp/node.cpp

@@ -173,6 +173,12 @@ Node::list_parameters(
   return node_parameters_->list_parameters(prefixes, depth);
 }
 
+std::vector<std::string>
+Node::get_node_names() const
+{
+  return node_graph_->get_node_names();
+}
+
 std::map<std::string, std::vector<std::string>>
 Node::get_topic_names_and_types() const
 {

rclcpp_lifecycle/include/rclcpp_lifecycle/lifecycle_node.hpp

@@ -300,6 +300,10 @@ public:
   void
   register_param_change_callback(CallbackT && callback);
 
+  RCLCPP_LIFECYCLE_PUBLIC
+  std::vector<std::string>
+  get_node_names() const;
+
   RCLCPP_LIFECYCLE_PUBLIC
   std::map<std::string, std::vector<std::string>>
   get_topic_names_and_types(bool no_demangle = false) const;

rclcpp_lifecycle/src/lifecycle_node.cpp

@@ -193,6 +193,12 @@ LifecycleNode::list_parameters(
   return node_parameters_->list_parameters(prefixes, depth);
 }
 
+std::vector<std::string>
+LifecycleNode::get_node_names() const
+{
+  return node_graph_->get_node_names();
+}
+
 std::map<std::string, std::vector<std::string>>
 LifecycleNode::get_topic_names_and_types(bool no_demangle) const
 {