程序代写代做代考 Java javascript ## Miscellaneous Node Helpers

## Miscellaneous Node Helpers

– Nan::MakeCallback()
– NAN_MODULE_INIT()
– Nan::Export()

### Nan::MakeCallback()

Wrappers around `node::MakeCallback()` providing a consistent API across all supported versions of Node.

Use `MakeCallback()` rather than using `v8::Function#Call()` directly in order to properly process internal Node functionality including domains, async hooks, the microtask queue, and other debugging functionality.

Signatures:

“`c++
v8::Local Nan::MakeCallback(v8::Local target,
v8::Local func,
int argc,
v8::Local* argv);
v8::Local Nan::MakeCallback(v8::Local target,
v8::Local symbol,
int argc,
v8::Local* argv);
v8::Local Nan::MakeCallback(v8::Local target,
const char* method,
int argc,
v8::Local* argv);
“`

### NAN_MODULE_INIT()

Used to define the entry point function to a Node add-on. Creates a function with a given `name` that receives a `target` object representing the equivalent of the JavaScript `exports` object.

See example below.

### Nan::Export()

A simple helper to register a `v8::FunctionTemplate` from a JavaScript-accessible method (see [Methods](./methods.md)) as a property on an object. Can be used in a way similar to assigning properties to `module.exports` in JavaScript.

Signature:

“`c++
void Export(v8::Local target, const char *name, Nan::FunctionCallback f)
“`

Also available as the shortcut `NAN_EXPORT` macro.

Example:

“`c++
NAN_METHOD(Foo) {
…
}

NAN_MODULE_INIT(Init) {
NAN_EXPORT(target, Foo);
}
“`