replace_string.py

# Copyright (c) 2019 Intel Corporation
#
# 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.
 
import tempfile
from typing import Dict, List, Optional, Text
 
import launch
 
 
class ReplaceString(launch.Substitution):
    """
    Substitution that replaces strings on a given file.
 
    Used in launch system
    """
 
    def __init__(
        self,
        source_file: launch.SomeSubstitutionsType,
        replacements: Dict,
        condition: Optional[launch.Condition] = None,
    ) -> None:
        super().__init__()
 
        from launch.utilities import (
            normalize_to_list_of_substitutions,
        )  # import here to avoid loop
 
        self.__source_file__source_file = normalize_to_list_of_substitutions(source_file)
        self.__replacements__replacements = {}
        for key in replacements:
            self.__replacements__replacements[key] = normalize_to_list_of_substitutions(
                replacements[key]
            )
        self.__condition__condition = condition
 
    @property
    def name(self) -> List[launch.Substitution]:
        """Getter for name."""
        return self.__source_file__source_file
 
    @property
    def condition(self) -> Optional[launch.Condition]:
        """Getter for condition."""
        return self.__condition__condition
 
    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.namename)
        if self.__condition__condition is None or self.__condition__condition.evaluate(context):
            output_file = tempfile.NamedTemporaryFile(mode='w', delete=False)
            replacements = self.resolve_replacementsresolve_replacements(context)
            try:
                input_file = open(yaml_filename, 'r')
                self.replacereplace(input_file, output_file, replacements)
            except Exception as err:  # noqa: B902
                print('ReplaceString substitution error: ', err)
            finally:
                input_file.close()
                output_file.close()
            return output_file.name
        else:
            return yaml_filename
 
    def resolve_replacements(self, context):
        resolved_replacements = {}
        for key in self.__replacements__replacements:
            resolved_replacements[key] = launch.utilities.perform_substitutions(
                context, self.__replacements__replacements[key]
            )
        return resolved_replacements
 
    def replace(self, input_file, output_file, replacements):
        for line in input_file:
            for key, value in replacements.items():
                if isinstance(key, str) and isinstance(value, str):
                    if key in line:
                        line = line.replace(key, value)
                else:
                    raise TypeError(
                        'A provided replacement pair is not a string. Both key and value should be'
                        'strings.'
                    )
            output_file.write(line)