Method DefineClass

napi-inl.h:4932–5005

template <typename T>
inline Function ObjectWrap<T>::DefineClass(
    Napi::Env env,
    const char* utf8name,
    const size_t props_count,
    const napi_property_descriptor* descriptors,
    void* data) {
  napi_status status;
  std::vector<napi_property_descriptor> props(props_count);

  // We copy the descriptors to a local array because before defining the class
  // we must replace static method property descriptors with value property
  // descriptors such that the value is a function-valued `napi_value` created
  // with `CreateFunction()`.
  //
  // This replacement could be made for instance methods as well, but V8 aborts
  // if we do that, because it expects methods defined on the prototype template
  // to have `FunctionTemplate`s.
  for (size_t index = 0; index < props_count; index++) {
    props[index] = descriptors[index];
    napi_property_descriptor* prop = &props[index];
    if (prop->method == T::StaticMethodCallbackWrapper) {
      status =
          CreateFunction(env,
                         utf8name,
                         prop->method,
                         static_cast<StaticMethodCallbackData*>(prop->data),
                         &(prop->value));
      NAPI_THROW_IF_FAILED(env, status, Function());
      prop->method = nullptr;
      prop->data = nullptr;
    } else if (prop->method == T::StaticVoidMethodCallbackWrapper) {
      status =
          CreateFunction(env,
                         utf8name,
                         prop->method,
                         static_cast<StaticVoidMethodCallbackData*>(prop->data),
                         &(prop->value));
      NAPI_THROW_IF_FAILED(env, status, Function());
      prop->method = nullptr;
      prop->data = nullptr;
    }
  }

  napi_value value;
  status = napi_define_class(env,
                             utf8name,
                             NAPI_AUTO_LENGTH,
                             T::ConstructorCallbackWrapper,
                             data,
                             props_count,
                             props.data(),
                             &value);
  NAPI_THROW_IF_FAILED(env, status, Function());

  // After defining the class we iterate once more over the property descriptors
  // and attach the data associated with accessors and instance methods to the
  // newly created JavaScript class.
  for (size_t idx = 0; idx < props_count; idx++) {