[foxy] Do not use event handler for loading composable nodes (#170)

launch_ros/launch_ros/actions/composable_node_container.py

@@ -19,8 +19,6 @@
 import warnings
 
 from launch.action import Action
-from launch.actions import RegisterEventHandler
-from launch.event_handlers.on_process_start import OnProcessStart
 from launch.launch_context import LaunchContext
 from launch.some_substitutions_type import SomeSubstitutionsType
 
@@ -100,16 +98,9 @@ def execute(self, context: LaunchContext) -> Optional[List[Action]]:
             from .load_composable_nodes import LoadComposableNodes
             # Perform load action once the container has started.
             load_actions = [
-                RegisterEventHandler(
-                    event_handler=OnProcessStart(
-                        target_action=self,
-                        on_start=[
-                            LoadComposableNodes(
-                                composable_node_descriptions=self.__composable_node_descriptions,
-                                target_container=self
-                            )
-                        ]
-                    )
+                LoadComposableNodes(
+                    composable_node_descriptions=self.__composable_node_descriptions,
+                    target_container=self
                 )
             ]
         container_actions = super().execute(context)  # type: Optional[List[Action]]

test_launch_ros/test/test_launch_ros/actions/test_composable_node_container.py

@@ -0,0 +1,104 @@
+# Copyright 2020 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tests for the ComposableNodeContainer Action."""
+
+import asyncio
+
+from launch import LaunchDescription
+from launch import LaunchService
+from launch.actions import DeclareLaunchArgument
+from launch.actions import GroupAction
+from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import ComposableNodeContainer
+from launch_ros.descriptions import ComposableNode
+from launch_ros.utilities import get_node_name_count
+
+import osrf_pycommon.process_utils
+
+TEST_CONTAINER_NAME = 'test_component_container_node_name'
+TEST_CONTAINER_NAMESPACE = 'test_component_container_namespace'
+TEST_NODE_NAME = 'test_composable_node_name'
+TEST_NODE_NAMESPACE = 'test_composable_node_namespace'
+
+
+def _assert_launch_no_errors(actions, *, timeout_sec=1):
+    ld = LaunchDescription(actions)
+    ls = LaunchService(debug=True)
+    ls.include_launch_description(ld)
+
+    loop = osrf_pycommon.process_utils.get_loop()
+    launch_task = loop.create_task(ls.run_async())
+    loop.run_until_complete(asyncio.sleep(timeout_sec))
+    if not launch_task.done():
+        loop.create_task(ls.shutdown())
+        loop.run_until_complete(launch_task)
+    assert 0 == launch_task.result()
+    return ls.context
+
+
+def test_composable_node_container():
+    """Nominal test for launching a ComposableNodeContainer."""
+    actions = [
+        ComposableNodeContainer(
+            package='rclcpp_components',
+            executable='component_container',
+            name=TEST_CONTAINER_NAME,
+            namespace=TEST_CONTAINER_NAMESPACE,
+            composable_node_descriptions=[
+                ComposableNode(
+                    package='composition',
+                    plugin='composition::Listener',
+                    name=TEST_NODE_NAME,
+                    namespace=TEST_NODE_NAMESPACE,
+                )
+            ],
+        ),
+    ]
+
+    context = _assert_launch_no_errors(actions)
+    assert get_node_name_count(context, f'/{TEST_CONTAINER_NAMESPACE}/{TEST_CONTAINER_NAME}') == 1
+    assert get_node_name_count(context, f'/{TEST_NODE_NAMESPACE}/{TEST_NODE_NAME}') == 1
+
+
+def test_composable_node_container_in_group_with_launch_configuration_in_description():
+    """
+    Test launch configuration is passed to ComposableNode description inside GroupAction.
+
+    This is a regression test for #114.
+    """
+    actions = [
+        GroupAction([
+            DeclareLaunchArgument(name='test_arg', default_value='True'),
+            ComposableNodeContainer(
+                package='rclcpp_components',
+                executable='component_container',
+                name=TEST_CONTAINER_NAME,
+                namespace=TEST_CONTAINER_NAMESPACE,
+                composable_node_descriptions=[
+                    ComposableNode(
+                        package='composition',
+                        plugin='composition::Listener',
+                        name=TEST_NODE_NAME,
+                        namespace=TEST_NODE_NAMESPACE,
+                        parameters=[{'use_sim_time': LaunchConfiguration('test_arg')}],
+                    )
+                ],
+            ),
+        ], scoped=True),
+    ]
+
+    context = _assert_launch_no_errors(actions)
+    assert get_node_name_count(context, f'/{TEST_CONTAINER_NAMESPACE}/{TEST_CONTAINER_NAME}') == 1
+    assert get_node_name_count(context, f'/{TEST_NODE_NAMESPACE}/{TEST_NODE_NAME}') == 1