Default external folder is chosen when content is fetched, reporting …

…a warning in case that user prefers another place

CMakeLists.txt

@@ -11,12 +11,6 @@ target_include_directories(LangulusCore INTERFACE source)
 
 message("Compiler: ${CMAKE_CXX_COMPILER_ID} - ${CMAKE_CXX_COMPILER_VERSION}")
 
-if(NOT DEFINED LANGULUS_EXTERNAL_DIRECTORY)
-    set(LANGULUS_EXTERNAL_DIRECTORY "${CMAKE_SOURCE_DIR}/external" CACHE PATH
-        "Place where external dependencies will be downloaded and configured")
-    message(WARNING "LANGULUS_EXTERNAL_DIRECTORY not defined, using default: ${LANGULUS_EXTERNAL_DIRECTORY}")
-endif()
-
 if(CMAKE_CXX_FLAGS)
     # Make sure trigraphs are disabled                                  
     STRING(FIND ${CMAKE_CXX_FLAGS} "/Zc:trigraphs" TRIGRAPHS_ENABLED)

LangulusUtilities.cmake

@@ -1,6 +1,10 @@
+include(FetchContent)
+
 function(fetch_langulus_module NAME)
     if(NOT DEFINED LANGULUS_EXTERNAL_DIRECTORY)
-        message(FATAL_ERROR "LANGULUS_EXTERNAL_DIRECTORY is not defined")
+        set(LANGULUS_EXTERNAL_DIRECTORY "${CMAKE_SOURCE_DIR}/external" CACHE PATH
+            "Place where external dependencies will be downloaded and configured")
+        message(WARNING "LANGULUS_EXTERNAL_DIRECTORY not defined, using default: ${LANGULUS_EXTERNAL_DIRECTORY}")
     endif()
 
     message(STATUS "Fetching external Langulus${NAME}...")
@@ -18,7 +22,9 @@ endfunction()
 
 function(fetch_external_module NAME GIT_REPOSITORY REPO GIT_TAG TAG)
     if(NOT DEFINED LANGULUS_EXTERNAL_DIRECTORY)
-        message(FATAL_ERROR "LANGULUS_EXTERNAL_DIRECTORY is not defined")
+        set(LANGULUS_EXTERNAL_DIRECTORY "${CMAKE_SOURCE_DIR}/external" CACHE PATH
+            "Place where external dependencies will be downloaded and configured")
+        message(WARNING "LANGULUS_EXTERNAL_DIRECTORY not defined, using default: ${LANGULUS_EXTERNAL_DIRECTORY}")
     endif()
 
     message(STATUS "Fetching external library ${NAME}...")