BT interface node works with web-service

rbs_bt_executor/launch/rbs_bt_web.launch.py

@@ -0,0 +1,59 @@
+"""
+  rbs_bt_web
+  ROS 2 launch program for Robossembler
+
+  @shalenikol release 0.1
+"""
+import os
+# import json
+
+from launch import LaunchDescription
+from launch_ros.actions import Node
+from launch.actions import DeclareLaunchArgument, OpaqueFunction, RegisterEventHandler
+from launch.substitutions import LaunchConfiguration
+from launch.event_handlers import OnExecutionComplete
+
+FILE_BT = "bt.xml"
+
+def launch_setup(context, *args, **kwargs):
+    # Initialize Arguments
+    bt_path = LaunchConfiguration("bt_path")
+    bt_path = bt_path.perform(context)
+
+    rbs_bt = Node(
+        package = "behavior_tree",
+        executable = "bt_engine",
+        parameters = [
+            {"bt_file_path": os.path.join(bt_path, FILE_BT)},
+            {"plugins": ["rbs_interface"]}
+        ]
+    )
+
+    bt_param = Node(
+        package="rbs_interface",
+        executable="bt_param.py",
+        parameters = [{"bt_path": bt_path}]
+    )
+    # nodes_to_start = [rbs_bt]
+    # return nodes_to_start
+    # return [bt_param]
+    return [
+            RegisterEventHandler(
+                event_handler=OnExecutionComplete(
+                    target_action=bt_param,
+                    on_completion=[rbs_bt],
+                )
+            ),
+            bt_param
+        ] # the order of elements is strictly required
+
+def generate_launch_description():
+    declared_arguments = []
+    declared_arguments.append(
+        DeclareLaunchArgument(
+            "bt_path",
+            default_value="''",
+            description="path to Behavior tree instance"
+        )
+    )
+    return LaunchDescription(declared_arguments + [OpaqueFunction(function=launch_setup)])