How to install multiple, doxygen-generated documentation conditionally with CMake?

Question

I am having a CMakeLists.txt that conditionally generates various formats of documentation based on the user configuration in the command line.

set(DOXYGEN_INPUT ${PROJECT_SOURCE_DIR}/docs/doxygen/Doxyfile.in)
set(DOXY_OUT ${PROJECT_SOURCE_DIR}/docs/Doxyfile)

if(GENERATE_QHP)
    message("Enabled the .qhp documentation")
    set(qch "qch")
    find_program(QHELPGEN_EXECUTABLE qhelpgenerator)
    if(NOT QHELPGEN_EXECUTABLE)
        message(FATAL_ERROR "Unable to build API documentation in qch format.")
    endif()
endif(GENERATE_QHP)

if(GENERATE_MAN)
    message("Enabled the unix man page documentation")
    set(man "man")
endif(GENERATE_MAN)

configure_file(${DOXYGEN_INPUT} ${DOXY_OUT} @ONLY)
message("Doxygen build started")

add_custom_target(doc ALL
    COMMAND ${DOXYGEN_EXECUTABLE} ${DOXY_OUT}
    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
    COMMENT "Generating API documentation with Doxygen"
    VERBATIM
    )

One way to install conditionally, is by writing multiple install inside ifs : if(GENERATE_HTML) install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/html DESTINATION ${CMAKE_INSTALL_DOCDIR}) endif(GENERATE_HTML) if(GENERATE_MAN) install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/man DESTINATION ${CMAKE_INSTALL_DOCDIR}) endif(GENERATE_MAN)

Is there any better way, like :

foreach(doc_type html;man;qch )
    install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/${doc_type} DESTINATION ${CMAKE_INSTALL_DOCDIR})
endforeach()

Answer 1

You nearly found the solution by yourself. Having a list of documentation strings is the way to go.

set(doc_types_to_install)

if(GENERATE_MAN)
...
list(APPEND doc_types_to_install "man")
endif()
#continue for other doc_types
foreach(doc_type ${doc_types_to_install})
...
endforeach()