example: add Addon<T> example

Signed-off-by: Gabriel Schulhof <[email protected]>
PR-URL: #209
Reviewed-By: Michael Dawson <[email protected]>

Author: gabrielschulhof

1_hello_world/node-addon-api-addon-class/binding.gyp

@@ -0,0 +1,14 @@
+{
+  "targets": [
+    {
+      "target_name": "hello",
+      "cflags!": [ "-fno-exceptions" ],
+      "cflags_cc!": [ "-fno-exceptions" ],
+      "sources": [ "hello.cc" ],
+      "include_dirs": [
+        "<!@(node -p \"require('node-addon-api').include\")"
+      ],
+      'defines': ['NAPI_DISABLE_CPP_EXCEPTIONS'],
+    }
+  ]
+}

1_hello_world/node-addon-api-addon-class/hello.cc

@@ -0,0 +1,17 @@
+#include <napi.h>
+
+class HelloAddon : public Napi::Addon<HelloAddon> {
+ public:
+  HelloAddon(Napi::Env env, Napi::Object exports) {
+    DefineAddon(exports, {
+      InstanceMethod("hello", &HelloAddon::Hello, napi_enumerable)
+    });
+  }
+
+ private:
+  Napi::Value Hello(const Napi::CallbackInfo& info) {
+    return Napi::String::New(info.Env(), "world");
+  }
+};
+
+NODE_API_ADDON(HelloAddon)

1_hello_world/node-addon-api-addon-class/hello.js

@@ -0,0 +1,3 @@
+var addon = require('bindings')('hello');
+
+console.log(addon.hello()); // 'world'

1_hello_world/node-addon-api-addon-class/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "hello_world",
+  "version": "0.0.0",
+  "description": "Node.js Addons Example #1",
+  "main": "hello.js",
+  "private": true,
+  "dependencies": {
+    "bindings": "~1.2.1",
+    "node-addon-api": "^4.0.0"
+  },
+  "scripts": {
+    "test": "node hello.js"
+  },
+  "gypfile": true
+}

README.md

@@ -9,6 +9,7 @@ Implementations of examples are named either after Node.js versions (`node_0.10`
 - [`nan`](https://github.com/nodejs/nan): C++-based abstraction between Node and direct V8 APIs.
 - [`Node-API`](https://nodejs.org/api/n-api.html): C-based API guaranteeing [ABI stability](https://nodejs.org/en/docs/guides/abi-stability/) across different node versions as well as JavaScript engines. (Node-API was previously known as N-API.)
 - [`node-addon-api`](https://github.com/nodejs/node-addon-api): header-only C++ wrapper classes which simplify the use of the C-based Node-API.
+- [`node-addon-api-addon-class`](https://github.com/nodejs/node-addon-api/tree/main/doc/addon.md): Similar to `node-addon-api`, but deriving from the `Napi::Addon` class. [1_hello_world](./1_hello_world) provides an example.
 
 Implementations against unsupported versions of Node.js are provided for
 completeness and historical context. They are not maintained.