Example of native modules.

Author: Ryan Kotzen

.gitignore

@@ -35,3 +35,5 @@ jspm_packages
 
 # Optional REPL history
 .node_repl_history
+
+node/native-modules/build/**

.idea/workspace.xml

@@ -2,4 +2,10 @@
 A repository for my Beer & Technology talk on MongoDB and Node.js
 
 # Further study
-Philip Roberts: What the heck is the event loop anyway? https://www.youtube.com/watch?v=8aGhZQkoFbQ
+Philip Roberts: What the heck is the event loop anyway? https://www.youtube.com/watch?v=8aGhZQkoFbQ
+
+#TODO
+* npm global modules
+* native modules
+* edge.js
+

README.md

@@ -67,6 +67,9 @@ Note that you can also install multiple dependencies at the same time. E.g.:
 
 > e.g. `npm i moment lodash express`
 
-#shrinkwrap
+This is all good and well, but how do I use a dependency once it has been installed?
+See index.js
 
-#Anatomy of the project folder.
+#Shrinkwrap - make mine to go!
+
+Once you are ready to deploy your app type `npm shrinkwrap` and this will freeze all of your dependencies, and their dependencies, and their dependencies, and their dependencies, etc and write it to the `npm-shrinkwrap.json` file in the root of your app. When your server hosting node does a `npm install`, this file will be used to install the exact dependencies you had on your dev/ci/cd box.

node/2-npm/README.md

@@ -0,0 +1,3 @@
+const moment = require("moment");
+const startTime = moment();
+console.log('Hello from %s!', startTime.fromNow()); //notice console.log by default uses util.format we played around with earlier.

node/2-npm/index.js

@@ -0,0 +1,8 @@
+# Source
+See [Writing Native Node.js Modules](https://blog.risingstack.com/writing-native-node-js-modules/)
+
+Windows: In an admin command prompt `npm i -g --production windows-build-tools`
+
+Run the following from within the `native-modules` folder
+`node-gyp configure`
+`node-gyp build`

node/native-modules/README.md

@@ -0,0 +1,8 @@
+{
+  "targets": [
+    {
+      "target_name": "addon",
+      "sources": [ "example.cc" ]
+    }
+  ]
+}

node/native-modules/binding.gyp

@@ -0,0 +1,41 @@
+#include <node.h>
+
+const int maxValue = 10;
+int numberOfCalls = 0;
+
+void WhoAmI(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  v8::Isolate* isolate = args.GetIsolate();
+  auto message = v8::String::NewFromUtf8(isolate, "I'm a Node Hero!");
+  args.GetReturnValue().Set(message);
+}
+
+void Increment(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  v8::Isolate* isolate = args.GetIsolate();
+
+  if (!args[0]->IsNumber()) {
+    isolate->ThrowException(v8::Exception::TypeError(
+          v8::String::NewFromUtf8(isolate, "Argument must be a number")));
+    return;
+  }
+
+  double argsValue = args[0]->NumberValue();
+  if (numberOfCalls + argsValue > maxValue) {
+    isolate->ThrowException(v8::Exception::Error(
+          v8::String::NewFromUtf8(isolate, "Counter went through the roof!")));
+    return;
+  }
+
+  numberOfCalls += argsValue;
+
+  auto currentNumberOfCalls =
+    v8::Number::New(isolate, static_cast<double>(numberOfCalls));
+
+  args.GetReturnValue().Set(currentNumberOfCalls);
+}
+
+void Initialize(v8::Local<v8::Object> exports) {
+  NODE_SET_METHOD(exports, "whoami", WhoAmI);
+  NODE_SET_METHOD(exports, "increment", Increment);
+}
+
+NODE_MODULE(module_name, Initialize)

node/native-modules/example.cc

@@ -0,0 +1,2 @@
+const myAddon  = require('./build/Release/addon');
+console.log(myAddon.whoami());