| ## Miscellaneous V8 Helpers |
| |
| - <a href="#api_nan_utf8_string"><b><code>Nan::Utf8String</code></b></a> |
| - <a href="#api_nan_get_current_context"><b><code>Nan::GetCurrentContext()</code></b></a> |
| - <a href="#api_nan_set_isolate_data"><b><code>Nan::SetIsolateData()</code></b></a> |
| - <a href="#api_nan_get_isolate_data"><b><code>Nan::GetIsolateData()</code></b></a> |
| - <a href="#api_nan_typedarray_contents"><b><code>Nan::TypedArrayContents</code></b></a> |
| |
| |
| <a name="api_nan_utf8_string"></a> |
| ### Nan::Utf8String |
| |
| Converts an object to a UTF-8-encoded character array. If conversion to a string fails (e.g. due to an exception in the toString() method of the object) then the length() method returns 0 and the * operator returns NULL. The underlying memory used for this object is managed by the object. |
| |
| An implementation of [`v8::String::Utf8Value`](https://v8docs.nodesource.com/node-8.16/d4/d1b/classv8_1_1_string_1_1_utf8_value.html) that is consistent across all supported versions of V8. |
| |
| Definition: |
| |
| ```c++ |
| class Nan::Utf8String { |
| public: |
| Nan::Utf8String(v8::Local<v8::Value> from); |
| |
| int length() const; |
| |
| char* operator*(); |
| const char* operator*() const; |
| }; |
| ``` |
| |
| <a name="api_nan_get_current_context"></a> |
| ### Nan::GetCurrentContext() |
| |
| A call to [`v8::Isolate::GetCurrent()->GetCurrentContext()`](https://v8docs.nodesource.com/node-8.16/d5/dda/classv8_1_1_isolate.html#a81c7a1ed7001ae2a65e89107f75fd053) that works across all supported versions of V8. |
| |
| Signature: |
| |
| ```c++ |
| v8::Local<v8::Context> Nan::GetCurrentContext() |
| ``` |
| |
| <a name="api_nan_set_isolate_data"></a> |
| ### Nan::SetIsolateData() |
| |
| A helper to provide a consistent API to [`v8::Isolate#SetData()`](https://v8docs.nodesource.com/node-8.16/d5/dda/classv8_1_1_isolate.html#a7acadfe7965997e9c386a05f098fbe36). |
| |
| Signature: |
| |
| ```c++ |
| void Nan::SetIsolateData(v8::Isolate *isolate, T *data) |
| ``` |
| |
| |
| <a name="api_nan_get_isolate_data"></a> |
| ### Nan::GetIsolateData() |
| |
| A helper to provide a consistent API to [`v8::Isolate#GetData()`](https://v8docs.nodesource.com/node-8.16/d5/dda/classv8_1_1_isolate.html#aabd223436bc1100a787dadaa024c6257). |
| |
| Signature: |
| |
| ```c++ |
| T *Nan::GetIsolateData(v8::Isolate *isolate) |
| ``` |
| |
| <a name="api_nan_typedarray_contents"></a> |
| ### Nan::TypedArrayContents<T> |
| |
| A helper class for accessing the contents of an ArrayBufferView (aka a typedarray) from C++. If the input array is not a valid typedarray, then the data pointer of TypedArrayContents will default to `NULL` and the length will be 0. If the data pointer is not compatible with the alignment requirements of type, an assertion error will fail. |
| |
| Note that you must store a reference to the `array` object while you are accessing its contents. |
| |
| Definition: |
| |
| ```c++ |
| template<typename T> |
| class Nan::TypedArrayContents { |
| public: |
| TypedArrayContents(v8::Local<Value> array); |
| |
| size_t length() const; |
| |
| T* const operator*(); |
| const T* const operator*() const; |
| }; |
| ``` |