Make custom_validators accessible from external library

[christophfroehlich]

With #213 it is straightforward to use a complete cpp library within another package. But how can I use a custom_validator file from a different package?

Is there a smarter way to include the file from here to another library than

find_package(control_toolbox)
# get include dirs from control_toolbox for the custom validators
get_target_property(TB_INCLUDE_DIRS control_toolbox::rate_limiter_parameters INTERFACE_INCLUDE_DIRECTORIES)
generate_parameter_library(diff_drive_controller_parameters
  src/diff_drive_controller_parameter.yaml
  ${TB_INCLUDE_DIRS}/control_toolbox/custom_validators.hpp
)

@AugusteBourgois any suggestions?
Changing the macro here to avoid a COPY but just use the correct include path control_toolbox/custom_validators.hpp?

generate_parameter_library/generate_parameter_library/cmake/generate_parameter_library.cmake

Lines 42 to 54 in 891c291

	if(${ARGC} EQUAL 3)
	cmake_path(SET IN_VALIDATE_HEADER ${CMAKE_CURRENT_SOURCE_DIR})
	cmake_path(APPEND IN_VALIDATE_HEADER ${ARGV2})
	cmake_path(GET IN_VALIDATE_HEADER FILENAME VALIDATE_HEADER_FILENAME)
	cmake_path(SET VALIDATE_HEADER ${LIB_INCLUDE_DIR})
	cmake_path(APPEND VALIDATE_HEADER ${VALIDATE_HEADER_FILENAME})
	# Copy the header file into the include directory
	file(COPY ${IN_VALIDATE_HEADER} DESTINATION ${LIB_INCLUDE_DIR})
	# necessary so that #include <param_file.hpp> can be used in the local package (deprecated)
	file(COPY ${IN_VALIDATE_HEADER} DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/include)
	endif()

[pac48]

@christophfroehlich I think inserting the include directly as specified, e.g. <control_toolbox/custom_validators.hpp> makes the most sense. That way, you can call target_include_directories or target_link_libraries on the generated target to make sure your custom header is in the included paths. For now, maybe the file should still be copied if the relative path exists, but otherwise, just insert it in the generated code anyway.

[AugusteBourgois]

@christophfroehlich to be sure I understand you problem correctly :

• You have two packages, A and B.
• You want to generate the parameter files in A, i.e. your .yaml config file is located there, and you call generate_parameter_library from A's CMakeLists.txt
• You have a custom validator, i.e. a .hpp file located in B, which you want to use in A's .yaml file.

Am I correct ?

[christophfroehlich]

exactly 🤔

[AugusteBourgois]

@pac48 do you mean you could write in A's CMakeLists.txt :

find_package(B REQUIRED)

generate_parameter_library(my_parameters_target
src/my_parameters_definition.yaml
B/custom_validator.hpp
)
target_link_libraries(my_parameters_target B::custom_validator)

[pac48]

@AugusteBourgois That looks right. I think one additional step would be to ensure custom_validator.hpp is installed by B in its CMake.