diff --git a/nav2_common/nav2_common/launch/__init__.py b/nav2_common/nav2_common/launch/__init__.py index 1f0638f81a..c25fadb220 100644 --- a/nav2_common/nav2_common/launch/__init__.py +++ b/nav2_common/nav2_common/launch/__init__.py @@ -12,5 +12,6 @@ # See the License for the specific language governing permissions and # limitations under the License. +from .has_node_params import HasNodeParams from .rewritten_yaml import RewrittenYaml from .replace_string import ReplaceString diff --git a/nav2_common/nav2_common/launch/has_node_params.py b/nav2_common/nav2_common/launch/has_node_params.py new file mode 100644 index 0000000000..21b8a32f9e --- /dev/null +++ b/nav2_common/nav2_common/launch/has_node_params.py @@ -0,0 +1,61 @@ +# Copyright (c) 2021 PAL Robotics S.L. +# +# 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. + +from typing import List +from typing import Text + +import yaml +import launch + + +class HasNodeParams(launch.Substitution): + """ + Substitution that checks if a param file contains parameters for a node. + + Used in launch system + """ + + def __init__(self, + source_file: launch.SomeSubstitutionsType, + node_name: Text) -> None: + super().__init__() + """ + Construct the substitution + + :param: source_file the parameter YAML file + :param: node_name the name of the node to check + """ + + # import here to avoid loop + from launch.utilities import normalize_to_list_of_substitutions + self.__source_file = normalize_to_list_of_substitutions(source_file) + self.__node_name = node_name + + @property + def name(self) -> List[launch.Substitution]: + """Getter for name.""" + return self.__source_file + + def describe(self) -> Text: + """Return a description of this substitution as a string.""" + return '' + + def perform(self, context: launch.LaunchContext) -> Text: + yaml_filename = launch.utilities.perform_substitutions( + context, self.name) + data = yaml.safe_load(open(yaml_filename, 'r')) + + if self.__node_name in data.keys(): + return "True" + return "False"