CMake.js Inclusion Function for ordinary CMake

readme.md

CMake.js Inclusion Function for ordinary CMake

I recently had an issue where my IDE (Visual Studio) had no support for CMake.js and this was my solution. This solution sets up all the CMake.js variables. By defining CMAKE_JS_INC and CMAKE_JS_LIB for use in your project. Just call setup_cmakejs() to define the variables. It is also compatible with Windows development environments. Linux and macOS are untested, but assumedly work just fine.

Happy coding!

Here's an example just in case you need it:

cmake_minimum_required(VERSION 3.2.2)

include("cmakejs.cmake")
setup_cmakejs()

project (my_project_name)
include_directories(${CMAKE_JS_INC})
file(GLOB SOURCE_FILES "main.cpp")
add_library(${PROJECT_NAME} SHARED ${SOURCE_FILES} ${CMAKE_JS_SRC})

set_target_properties(${PROJECT_NAME} PROPERTIES 
		PREFIX 				""
		SUFFIX 				".node"
        	RUNTIME_OUTPUT_DIRECTORY 	${ARTIFACTS_DIRECTORY}
        	LINKER_LANGUAGE 		CXX
		)

target_link_libraries(${PROJECT_NAME} ${CMAKE_JS_LIB})

cmakejs.cmake

# Authored by Graham Dianaty for Bitlogix Technologies. Based on code from Rene Hollander. ==========//
function(setup_cmakejs)
    find_program(CMAKEJS "cmake-js")
    find_program(NPM "npm")
    # first, check if we have NPM:
    if(NPM)
        message(VERBOSE "NPM found.")
    else()
        message(FATAL_ERROR "NPM not found. This project requires Node.js")
    endif()

    if(CMAKEJS)
        message(VERBOSE "CMake.js found.")
    else()
        message(ERROR "CMake.js not found, installing globally...")
        exec_program(${NPM_COMMAND} ${CMAKE_CURRENT_SOURCE_DIR} ARGS install -g cmake-js OUTPUT_VARIABLE NPM_OUTPUT)
        message(STATUS "CMake.js should now be installed.")
        message(VERBOSE ${NPM_OUTPUT})
    endif()


    if(WIN32)
        set(NPM_COMMAND ${NPM}.cmd)
        set(CMAKEJS_CMD ${CMAKEJS}.cmd)
    else()
        set(NPM_COMMAND ${NPM})
        set(CMAKEJS_CMD ${CMAKEJS})
    endif()

  function(GET_VARIABLE INPUT_STRING VARIABLE_TO_SELECT OUTPUT_VARIABLE)
    set(SEARCH_STRING "${VARIABLE_TO_SELECT}=\"")
    string(LENGTH "${SEARCH_STRING}" SEARCH_STRING_LENGTH)
    string(LENGTH "${INPUT_STRING}" INPUT_STRING_LENGTH)

    string(FIND "${INPUT_STRING}" "${VARIABLE_TO_SELECT}=\"" SEARCH_STRING_INDEX)

    math(EXPR SEARCH_STRING_INDEX "${SEARCH_STRING_INDEX}+${SEARCH_STRING_LENGTH}")

    string(SUBSTRING "${INPUT_STRING}" ${SEARCH_STRING_INDEX} ${INPUT_STRING_LENGTH} AFTER_SEARCH_STRING)
    string(FIND "${AFTER_SEARCH_STRING}" "\"" QUOTE_INDEX)
    string(SUBSTRING "${AFTER_SEARCH_STRING}" "0" "${QUOTE_INDEX}" RESULT_STRING)
    set("${OUTPUT_VARIABLE}" "${RESULT_STRING}" PARENT_SCOPE)
  endfunction(GET_VARIABLE)

  string(TOLOWER "${CMAKE_BUILD_TYPE}" CMAKE_BUILD_TYPE_LOWER)
  if (CMAKE_BUILD_TYPE_LOWER STREQUAL "debug")
    exec_program("${CMAKEJS_CMD}" ${CMAKE_CURRENT_SOURCE_DIR}
                 ARGS print-configure --debug
                 OUTPUT_VARIABLE CMAKE_JS_OUTPUT
    )
  else()
    exec_program("${CMAKEJS_CMD}" ${CMAKE_CURRENT_SOURCE_DIR}
                 ARGS print-configure
                 OUTPUT_VARIABLE CMAKE_JS_OUTPUT
    )
  endif ()

  message(VERBOSE ${CMAKE_JS_OUTPUT})

  get_variable("${CMAKE_JS_OUTPUT}" "CMAKE_JS_INC" CMAKE_JS_INC)
  set(CMAKE_JS_INC "${CMAKE_JS_INC}" PARENT_SCOPE)

  get_variable("${CMAKE_JS_OUTPUT}" "CMAKE_JS_LIB" CMAKE_JS_LIB)
  set(CMAKE_JS_LIB "${CMAKE_JS_LIB}" PARENT_SCOPE)

  get_variable("${CMAKE_JS_OUTPUT}" "CMAKE_LIBRARY_OUTPUT_DIRECTORY" CMAKE_LIBRARY_OUTPUT_DIRECTORY)
  set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_LIBRARY_OUTPUT_DIRECTORY}" PARENT_SCOPE)
  
  message(STATUS "[CMakeJS] Set up variables.")
endfunction(setup_cmakejs)

I tried this code and fine that my cmake-js on Windows don't quote the parameter, so the string search failed. Here's my GET_VARIABLE that make it works:

function(GET_VARIABLE INPUT_STRING VARIABLE_TO_SELECT OUTPUT_VARIABLE)
    set(SEARCH_STRING "${VARIABLE_TO_SELECT}=\"")
    string(LENGTH "${SEARCH_STRING}" SEARCH_STRING_LENGTH)
    string(LENGTH "${INPUT_STRING}" INPUT_STRING_LENGTH)

    string(REPLACE "\\\\" "\\" INPUT_STRING "${INPUT_STRING}")

    string(FIND "${INPUT_STRING}" "${VARIABLE_TO_SELECT}=\"" SEARCH_STRING_INDEX)

    if(SEARCH_STRING_INDEX EQUAL -1)
        string(FIND "${INPUT_STRING}" "${VARIABLE_TO_SELECT}=" SEARCH_STRING_INDEX)

        math(EXPR SEARCH_STRING_INDEX "${SEARCH_STRING_INDEX}+${SEARCH_STRING_LENGTH}-1")

        string(SUBSTRING "${INPUT_STRING}" ${SEARCH_STRING_INDEX} ${INPUT_STRING_LENGTH} AFTER_SEARCH_STRING)
        string(FIND "${AFTER_SEARCH_STRING}" "'" QUOTE_INDEX)
        string(SUBSTRING "${AFTER_SEARCH_STRING}" "0" "${QUOTE_INDEX}" RESULT_STRING)
        set("${OUTPUT_VARIABLE}" "${RESULT_STRING}" PARENT_SCOPE)

    else()

        math(EXPR SEARCH_STRING_INDEX "${SEARCH_STRING_INDEX}+${SEARCH_STRING_LENGTH}")

        string(SUBSTRING "${INPUT_STRING}" ${SEARCH_STRING_INDEX} ${INPUT_STRING_LENGTH} AFTER_SEARCH_STRING)
        string(FIND "${AFTER_SEARCH_STRING}" "\"" QUOTE_INDEX)
        string(SUBSTRING "${AFTER_SEARCH_STRING}" "0" "${QUOTE_INDEX}" RESULT_STRING)
        set("${OUTPUT_VARIABLE}" "${RESULT_STRING}" PARENT_SCOPE)

    endif()
endfunction(GET_VARIABLE)

Full disclosure: all of my knowledge about CMake-js has fallen out of my brain, and these scripts are now Martian to me. Not entirely sure how to help.

Hi, How about add a switch for pnpm, yarn and other package manager support?

If you define the CMake variable for NPM_COMMAND with the desired package manager's executable elsewhere in your project (i.e. prior to function being called) you should be able to get this functionality. As far as I know, the syntax used above should work with yarn and will
almost definitely work with pnpm.