update to create config file which is independent from actual install location

CMakeLists.txt

@@ -173,15 +173,35 @@ install(DIRECTORY example/
 # Provide config and version files to be used by other applications
 # ===============================
 
-export(PACKAGE ${PROJECT_NAME})
-
-# cmake-modules
-CONFIGURE_FILE(${PROJECT_NAME}Config.cmake.in
-    ${PROJECT_NAME}Config.cmake
-    @ONLY)
-CONFIGURE_FILE(${PROJECT_NAME}ConfigVersion.cmake.in
-    ${PROJECT_NAME}ConfigVersion.cmake
-    @ONLY)
+################################################################################
+# Export package for use from the build tree
+EXPORT( PACKAGE ${PROJECT_NAME} )
+
+# Create the RapidJSONConfig.cmake file for other cmake projects.
+# ... for the build tree
+SET( CONFIG_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+SET( CONFIG_DIR ${CMAKE_CURRENT_BINARY_DIR})
+CONFIGURE_FILE( ${CMAKE_CURRENT_SOURCE_DIR}/${PROJECT_NAME}Config.cmake.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake @ONLY )
+CONFIGURE_FILE(${CMAKE_CURRENT_SOURCE_DIR}/${PROJECT_NAME}ConfigVersion.cmake.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake @ONLY)
+
+# ... for the install tree
+SET( CMAKECONFIG_INSTALL_DIR lib/cmake/${PROJECT_NAME} )
+FILE( RELATIVE_PATH REL_INCLUDE_DIR
+    "${CMAKE_INSTALL_PREFIX}/${CMAKECONFIG_INSTALL_DIR}"
+    "${CMAKE_INSTALL_PREFIX}/include" )
+
+SET( ${PROJECT_NAME}_INCLUDE_DIR "\${${PROJECT_NAME}_CMAKE_DIR}/${REL_INCLUDE_DIR}" )
+SET( CONFIG_SOURCE_DIR )
+SET( CONFIG_DIR )
+CONFIGURE_FILE( ${CMAKE_CURRENT_SOURCE_DIR}/${PROJECT_NAME}Config.cmake.in
+    ${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/${PROJECT_NAME}Config.cmake @ONLY )
+
+INSTALL(FILES "${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/${PROJECT_NAME}Config.cmake"
+        DESTINATION ${CMAKECONFIG_INSTALL_DIR} )
+
+# Install files
 INSTALL(FILES
     ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake
     ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake

RapidJSONConfig.cmake.in

-get_filename_component(RAPIDJSON_CMAKE_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
-set(RAPIDJSON_INCLUDE_DIRS "@INCLUDE_INSTALL_DIR@")
-message(STATUS "RapidJSON found. Headers: ${RAPIDJSON_INCLUDE_DIRS}")
+################################################################################
+# RapidJSON source dir
+set( RapidJSON_SOURCE_DIR "@CONFIG_SOURCE_DIR@")
+
+################################################################################
+# RapidJSON build dir
+set( RapidJSON_DIR "@CONFIG_DIR@")
+
+################################################################################
+# Compute paths
+get_filename_component(RapidJSON_CMAKE_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
+
+set( RapidJSON_INCLUDE_DIR  "@RapidJSON_INCLUDE_DIR@" )
+set( RapidJSON_INCLUDE_DIRS  "@RapidJSON_INCLUDE_DIR@" )
+message(STATUS "RapidJSON found. Headers: ${RapidJSON_INCLUDE_DIRS}")