N-API provides a set of APIs that allow JavaScript code to
call back into native code. N-API APIs that support calling back
into native code take in a callback functions represented by
the napi_callback
type. When the JavaScript VM calls back to
native code, the napi_callback
function provided is invoked. The APIs
documented in this section allow the callback function to do the
following:
- Get information about the context in which the callback was invoked.
- Get the arguments passed into the callback.
- Return a
napi_value
back from the callback.
Additionally, N-API provides a set of functions which allow calling JavaScript functions from native code. One can either call a function like a regular JavaScript function call, or as a constructor function.
Any non-NULL
data which is passed to this API via the data
field of the
napi_property_descriptor
items can be associated with object
and freed
whenever object
is garbage-collected by passing both object
and the data to
[napi_add_finalizer
][].