add IncludeLaunchDescription action (#120)

fixes #115

Signed-off-by: William Woodall <[email protected]>

launch/launch/__init__.py

@@ -23,6 +23,7 @@
 from .launch_context import LaunchContext
 from .launch_description import LaunchDescription
 from .launch_description_entity import LaunchDescriptionEntity
+from .launch_description_source import LaunchDescriptionSource
 from .launch_introspector import LaunchIntrospector
 from .launch_service import LaunchService
 from .some_actions_type import SomeActionsType
@@ -41,6 +42,7 @@
     'LaunchContext',
     'LaunchDescription',
     'LaunchDescriptionEntity',
+    'LaunchDescriptionSource',
     'LaunchIntrospector',
     'LaunchService',
     'SomeActionsType',

launch/launch/actions/__init__.py

@@ -16,6 +16,7 @@
 
 from .emit_event import EmitEvent
 from .execute_process import ExecuteProcess
+from .include_launch_description import IncludeLaunchDescription
 from .log_info import LogInfo
 from .opaque_function import OpaqueFunction
 from .register_event_handler import RegisterEventHandler
@@ -25,6 +26,7 @@
 __all__ = [
     'EmitEvent',
     'ExecuteProcess',
+    'IncludeLaunchDescription',
     'LogInfo',
     'OpaqueFunction',
     'RegisterEventHandler',

launch/launch/actions/include_launch_description.py

@@ -0,0 +1,40 @@
+# Copyright 2018 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.
+
+"""Module for the IncludeLaunchDescription action."""
+
+from typing import List
+
+from ..action import Action
+from ..launch_context import LaunchContext
+from ..launch_description_entity import LaunchDescriptionEntity
+from ..launch_description_source import LaunchDescriptionSource
+
+
+class IncludeLaunchDescription(Action):
+    """Action that includes a launch description source and yields its entities when visited."""
+
+    def __init__(self, launch_description_source: LaunchDescriptionSource) -> None:
+        """Constructor."""
+        super().__init__()
+        self.__launch_description_source = launch_description_source
+
+    @property
+    def launch_description_source(self) -> LaunchDescriptionSource:
+        """Getter for self.__launch_description_source."""
+        return self.__launch_description_source
+
+    def visit(self, context: LaunchContext) -> List[LaunchDescriptionEntity]:
+        """Override visit to return an Entity rather than an action."""
+        return [self.__launch_description_source.launch_description]

launch/launch/launch_description_source.py

@@ -0,0 +1,57 @@
+# Copyright 2018 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.
+
+"""Module for the LaunchDescriptionSource class."""
+
+from .launch_description import LaunchDescription
+
+
+class LaunchDescriptionSource:
+    """Encapsulation of a launch description, where it comes from, and how it was generated."""
+
+    def __init__(
+        self,
+        launch_description: LaunchDescription,
+        location: str = '<string>',
+        method: str = 'unspecified mechanism from a script',
+    ) -> None:
+        """
+        Constructor.
+
+        For example, loading a file called ``example.launch.py`` for inclusion
+        might end up setting `location` to ``/path/to/example.launch.py`` and
+        the ``method`` to be ``interpreted python launch file``.
+
+        :param launch_description: the launch description that this source represents
+        :param location: the location from where this launch description was loaded if applicable
+        :param method: the method by which the launch description was generated
+        """
+        self.__launch_description = launch_description
+        self.__location = location
+        self.__method = method
+
+    @property
+    def launch_description(self) -> LaunchDescription:
+        """Getter for self.__launch_description."""
+        return self.__launch_description
+
+    @property
+    def location(self) -> str:
+        """Getter for self.__location."""
+        return self.__location
+
+    @property
+    def method(self) -> str:
+        """Getter for self.__method."""
+        return self.__method

launch/test/launch/actions/test_include_launch_description.py

@@ -0,0 +1,46 @@
+# Copyright 2018 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 IncludeLaunchDescription action class."""
+
+from launch import LaunchDescription
+from launch import LaunchDescriptionSource
+from launch.actions import IncludeLaunchDescription
+
+
+def test_include_launch_description_constructors():
+    """Test the constructors for IncludeLaunchDescription class."""
+    IncludeLaunchDescription(LaunchDescriptionSource(LaunchDescription()))
+
+
+def test_include_launch_description_methods():
+    """Test the methods of the Action class."""
+    class MockLaunchContext:
+        ...
+
+    ld = LaunchDescription()
+    action = IncludeLaunchDescription(LaunchDescriptionSource(ld))
+    assert 'IncludeLaunchDescription' in action.describe()
+    assert isinstance(action.describe_sub_entities(), list)
+    assert isinstance(action.describe_conditional_sub_entities(), list)
+    assert action.visit(MockLaunchContext()) == [ld]
+    assert action.get_asyncio_future() is None
+
+    ld2 = LaunchDescription([action])
+    action2 = IncludeLaunchDescription(LaunchDescriptionSource(ld2))
+    assert 'IncludeLaunchDescription' in action2.describe()
+    assert isinstance(action2.describe_sub_entities(), list)
+    assert isinstance(action2.describe_conditional_sub_entities(), list)
+    assert action2.visit(MockLaunchContext()) == [ld2]
+    assert action2.get_asyncio_future() is None

launch/test/launch/test_action.py

@@ -23,7 +23,7 @@ def test_action_constructors():
 
 
 def test_action_methods():
-    """Test the moethods of the Action class."""
+    """Test the methods of the Action class."""
     class MockLaunchContext:
         ...