| # HandleScope | |
| The HandleScope class is used to manage the lifetime of object handles | |
| which are created through the use of node-addon-api. These handles | |
| keep an object alive in the heap in order to ensure that the objects | |
| are not collected while native code is using them. | |
| A handle may be created when any new node-addon-api Value or one | |
| of its subclasses is created or returned. For more details refer to | |
| the section titled [Object lifetime management](object_lifetime_management.md). | |
| ## Methods | |
| ### Constructor | |
| Creates a new handle scope on the stack. | |
| ```cpp | |
| Napi::HandleScope::HandleScope(Napi::Env env); | |
| ``` | |
| - `[in] env`: The environment in which to construct the `Napi::HandleScope` object. | |
| Returns a new `Napi::HandleScope` | |
| ### Constructor | |
| Creates a new handle scope on the stack. | |
| ```cpp | |
| Napi::HandleScope::HandleScope(Napi::Env env, Napi::HandleScope scope); | |
| ``` | |
| - `[in] env`: `Napi::Env` in which the scope passed in was created. | |
| - `[in] scope`: pre-existing `Napi::HandleScope`. | |
| Returns a new `Napi::HandleScope` instance which wraps the `napi_handle_scope` | |
| handle passed in. This can be used to mix usage of the C Node-API | |
| and node-addon-api. | |
| ```cpp | |
| operator Napi::HandleScope::napi_handle_scope() const | |
| ``` | |
| Returns the Node-API `napi_handle_scope` wrapped by the `Napi::EscapableHandleScope` object. | |
| This can be used to mix usage of the C Node-API and node-addon-api by allowing | |
| the class to be used be converted to a `napi_handle_scope`. | |
| ### Destructor | |
| ```cpp | |
| Napi::HandleScope::~HandleScope(); | |
| ``` | |
| Deletes the `Napi::HandleScope` instance and allows any objects/handles created | |
| in the scope to be collected by the garbage collector. There is no | |
| guarantee as to when the garbage collector will do this. | |
| ### Env | |
| ```cpp | |
| Napi::Env Napi::HandleScope::Env() const; | |
| ``` | |
| Returns the `Napi::Env` associated with the `Napi::HandleScope`. | |
| ## Example | |
| ```cpp | |
| for (int i = 0; i < LOOP_MAX; i++) { | |
| Napi::HandleScope scope(info.Env()); | |
| std::string name = std::string("inner-scope") + std::to_string(i); | |
| Napi::Value newValue = Napi::String::New(info.Env(), name.c_str()); | |
| // do something with newValue | |
| }; | |
| ``` | |
| For more details refer to the section titled [Object lifetime | |
| management](object_lifetime_management.md). |