Update README.md

README.md

@@ -1,8 +1,49 @@
 # hcm-node
+
 Node.js package code encapsulates APIs of the HUAWEI Push Kit server.
 
 ## Installation
 
 ```bash
 $ npm i hcm-node
 ```
+
+## Usage
+
+```typescript
+import HCM from 'hcm-node';
+import { Messaging } from 'hcm-node/dist/push/messaging';
+
+const hcm = new HCM();
+hcm.init({
+  appId: '<YOUR-APP-ID>',
+  appSecret: '<YOUR-APP-SECRET>',
+  authUrl: 'https://oauth-login.cloud.huawei.com/oauth2/v2/token',
+  pushUrl: 'https://push-api.cloud.huawei.com/v1'
+);
+const hcmDispatcher = hcm.messaging().messaging;
+
+try {
+  const response = hcmDispatcher.send(message, false);
+
+  /**
+   * HCM Response code for success = 80000000
+   * more info @ https://developer.huawei.com/consumer/en/doc/development/HMS-References/push-sendapi
+  */
+  if (response.code != '80000000') {
+    throwError(response);
+  }
+} catch(error) {
+  throwError(error);
+}
+
+function throwError(detail: any): void {
+  console.error({
+      message: 'push notification dispatch failed',
+      details: error,
+    });
+
+  throw new Error('External error');
+}
+
+```