napi create external

napi_status napi_create_external(napi_env env,
                                 void* data,
                                 napi_finalize finalize_cb,
                                 void* finalize_hint,
                                 napi_value* result)

• [in] env: The environment that the API is invoked under.
• [in] data: Raw pointer to the external data.
• [in] finalize_cb: Optional callback to call when the external value is being collected. [napi_finalize][] provides more details.
• [in] finalize_hint: Optional hint to pass to the finalize callback during collection.
• [out] result: A napi_value representing an external value.

Returns napi_ok if the API succeeded.

This API allocates a JavaScript value with external data attached to it. This is used to pass external data through JavaScript code, so it can be retrieved later by native code using [napi_get_value_external][].

The API adds a napi_finalize callback which will be called when the JavaScript object just created is ready for garbage collection. It is similar to napi_wrap() except that:

• the native data cannot be retrieved later using napi_unwrap(),
• nor can it be removed later using napi_remove_wrap(), and
• the object created by the API can be used with napi_wrap().

The created value is not an object, and therefore does not support additional properties. It is considered a distinct value type: calling napi_typeof() with an external value yields napi_external.