feat: added possibility to start module with C++ code enabled (#30)

Author: Patys

README.md

@@ -14,6 +14,7 @@ If you want to create your own React Native module, scaffolding the project can
 - [ESLint](https://eslint.org/), [Prettier](https://prettier.io/), [TypeScript](https://www.typescriptlang.org/) and [Husky](https://github.com/typicode/husky) pre-configured
 - Bob pre-configured to compile your files
 - CircleCI pre-configured to run tests on the CI
+- Use C++ code to boost performance of your modules
 
 <img src="assets/bob-create.gif" width="480px" height="auto">
 
@@ -26,6 +27,7 @@ Bob can build code for following targets:
 - Flow definitions (copies .js files to .flow files)
 - TypeScript definitions (uses `tsc` to generate declaration files)
 - Android AAR files
+- C++ modules
 
 ## Why
 

src/create.ts

@@ -12,6 +12,7 @@ import pack from '../package.json';
 
 const TEMPLATE = path.resolve(__dirname, '../templates/library');
 const BINARIES = /(gradlew|\.(jar|keystore|png|jpg|gif))$/;
+const CPP_FILES = path.resolve(__dirname, '../templates/cppLibrary');
 
 export default async function create(argv: yargs.Arguments<any>) {
   const folder = path.join(process.cwd(), argv.name);
@@ -51,6 +52,7 @@ export default async function create(argv: yargs.Arguments<any>) {
     authorEmail,
     authorUrl,
     githubUrl: repo,
+    useCpp,
   } = (await inquirer.prompt([
     {
       type: 'input',
@@ -118,13 +120,20 @@ export default async function create(argv: yargs.Arguments<any>) {
       },
       validate: input => /^https?:\/\//.test(input) || 'Must be a valid URL',
     },
+    {
+      type: 'confirm',
+      name: 'useCpp',
+      message: 'Does your library use C++ code?',
+      default: false,
+    },
   ])) as {
     slug: string;
     description: string;
     authorName: string;
     authorEmail: string;
     authorUrl: string;
     githubUrl: string;
+    useCpp: boolean;
   };
 
   const project = slug.replace(/^(react-native-|@[^/]+\/)/, '');
@@ -143,6 +152,7 @@ export default async function create(argv: yargs.Arguments<any>) {
         .slice(1)}`,
       package: slug.replace(/[^a-z0-9]/g, '').toLowerCase(),
       podspec: slug.replace(/[^a-z0-9]+/g, '-').replace(/^-/, ''),
+      useCpp,
     },
     author: {
       name: authorName,
@@ -176,6 +186,9 @@ export default async function create(argv: yargs.Arguments<any>) {
   };
 
   await copyDir(TEMPLATE, folder);
+  if (options.project.useCpp) {
+    await copyDir(CPP_FILES, folder);
+  }
 
   try {
     await spawn.sync(

templates/cppLibrary/android/CMakeLists.txt

@@ -0,0 +1,15 @@
+cmake_minimum_required(VERSION 3.4.1)
+
+set (CMAKE_VERBOSE_MAKEFILE ON)
+set (CMAKE_CXX_STANDARD 11)
+
+add_library(cpp
+            SHARED
+            ../cpp/example.cpp
+            cpp-adapter.cpp
+)
+
+# Specifies a path to native header files.
+include_directories(
+            ../cpp
+)

templates/cppLibrary/android/cpp-adapter.cpp

@@ -0,0 +1,8 @@
+#include <jni.h>
+#include "example.h"
+
+extern "C"
+JNIEXPORT jint JNICALL
+Java_com_<%= project.package %>_<%= project.name %>Module_nativeMultiply(JNIEnv *env, jclass type, jint a, jint b) {
+    return example::multiply(a, b);
+}

templates/cppLibrary/cpp/example.cpp

@@ -0,0 +1,7 @@
+#include "example.h"
+
+namespace example {
+	int multiply(int a, int b) {
+		return a * b;
+	}
+}

templates/cppLibrary/cpp/example.h

@@ -0,0 +1,8 @@
+#ifndef EXAMPLE_H
+#define EXAMPLE_H
+
+namespace example {
+  int multiply(int a, int b);
+}
+
+#endif /* EXAMPLE_H */

templates/library/<%= project.podspec %>.podspec

@@ -13,7 +13,12 @@ Pod::Spec.new do |s|
   s.platforms    = { :ios => "9.0" }
   s.source       = { :git => "<%= repo %>.git", :tag => "#{s.version}" }
 
-  s.source_files = "ios/**/*.{h,m}"
+  s.source_files = "ios/**/*.{h,m,mm}"
 
+  <% if(project.useCpp==true){ %>
+  s.source_files = "ios/**/*.{h,m,mm}", "cpp/**/*.{h,cpp}"
+   <% } else{ %>
+  s.source_files = "ios/**/*.{h,m,mm}"
+  <% } %>
   s.dependency "React"
 end

templates/library/android/build.gradle

@@ -33,7 +33,22 @@ android {
     targetSdkVersion getExtOrIntegerDefault('targetSdkVersion')
     versionCode 1
     versionName "1.0"
+    <%if (project.useCpp==true) {%>
+    externalNativeBuild {
+        cmake {
+            cppFlags "-O2 -frtti -fexceptions -Wall -fstack-protector-all"
+            abiFilters 'x86', 'x86_64', 'armeabi-v7a', 'arm64-v8a'
+        }
+    }
+    <%}%>
+  }
+  <%if (project.useCpp==true) {%>
+  externalNativeBuild {
+      cmake {
+          path "CMakeLists.txt"
+      }
   }
+  <%}%>
   buildTypes {
     release {
       minifyEnabled false

templates/library/android/src/main/java/com/<%= project.package %>/<%= project.name %>Module.kt

@@ -17,4 +17,23 @@ class <%= project.name %>Module(reactContext: ReactApplicationContext) : ReactCo
     fun getDeviceName(promise: Promise) {
         promise.resolve(android.os.Build.MODEL)
     }
+    <%if (project.useCpp==true) {%>
+      
+    @ReactMethod
+    fun multiply(a: Int, b: Int, promise: Promise) {
+      promise.resolve(nativeMultiply(a, b));
+    }
+
+    external fun nativeMultiply(a: Int, b: Int): Int;
+
+    companion object
+    {
+
+        // Used to load the 'native-lib' library on application startup.
+        init
+        {
+            System.loadLibrary("cpp")
+        }
+    }
+    <%}%>
 }

templates/library/example/src/App.tsx

@@ -4,14 +4,24 @@ import <%= project.name %> from '<%= project.slug %>';
 
 export default function App() {
   const [deviceName, setDeviceName] = React.useState('');
+  <%if (project.useCpp==true) {%>
+  const [value, setValue] = React.useState();
+  <%}%>
+
 
   React.useEffect(() => {
     <%= project.name %>.getDeviceName().then(setDeviceName);
+    <%if (project.useCpp==true) {%>
+    <%= project.name %>.multiply(2, 3).then(setValue);
+    <%}%>
   }, []);
 
   return (
     <View style={styles.container}>
       <Text>Device name: {deviceName}</Text>
+      <%if (project.useCpp==true) {%>
+      <Text>C++ mulitply value: {value}</Text>
+      <%}%>
     </View>
   );
 }