Added support for ESP-IDF component build (closes #1562)

CHANGELOG.md

@@ -13,6 +13,7 @@ HEAD
 * Fixed warning `definition of implicit copy constructor for 'MsgPackDeserializer' is deprecated because it has a user-declared copy assignment operator`
 * Added `JsonArray::clear()` (issue #1597)
 * Fixed `JsonVariant::as<unsigned>()` (issue #1601)
+* Added support for ESP-IDF component build (PR #1562 by @qt1)
 
 v6.18.0 (2021-05-05)
 -------

CMakeLists.txt

@@ -4,6 +4,13 @@
 
 cmake_minimum_required(VERSION 3.3)
 
+if(ESP_PLATFORM)
+   # Build ArduinoJson as an ESP-IDF component
+   idf_component_register(INCLUDE_DIRS src)
+   target_compile_definitions(${COMPONENT_LIB} INTERFACE ARDUINOJSON_EMBEDDED_MODE=1)
+   return()
+endif()
+
 project(ArduinoJson VERSION 6.18.0)
 
 if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME)