- exported targets go to separate generated file and package config file generated from template to use automatic package resolving and resolution logic

 CMake  provides helpers to generate config file. Generated config file has usefull macro check_required_components() to set necessary variables like PackageName_FOUND if requirements has been satisfied. An absence of dedicated config file confuses user project as necessary variables are not set.

Author: sergeyrachev

CMakeLists.txt

@@ -177,11 +177,13 @@ if(JSONCPP_WITH_CMAKE_PACKAGE)
     include(CMakePackageConfigHelpers)
     install(EXPORT jsoncpp
         DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/jsoncpp
-        FILE        jsoncppConfig.cmake)
+        FILE        jsoncpp-targets.cmake)
+    configure_package_config_file(jsoncppConfig.cmake.in ${CMAKE_CURRENT_BINARY_DIR}/jsoncppConfig.cmake INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/jsoncpp)
+
     write_basic_package_version_file("${CMAKE_CURRENT_BINARY_DIR}/jsoncppConfigVersion.cmake"
         VERSION ${PROJECT_VERSION}
         COMPATIBILITY SameMajorVersion)
-    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/jsoncppConfigVersion.cmake
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/jsoncppConfigVersion.cmake ${CMAKE_CURRENT_BINARY_DIR}/jsoncppConfig.cmake
         DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/jsoncpp)
 endif()
 

jsoncppConfig.cmake.in

@@ -0,0 +1,10 @@
+cmake_policy(PUSH)
+cmake_policy(VERSION 3.0)
+
+@PACKAGE_INIT@
+
+include ( "${CMAKE_CURRENT_LIST_DIR}/jsoncpp-targets.cmake" )
+
+check_required_components(JsonCpp)
+
+cmake_policy(POP)