From 1151263bd42629d80b862d87af6285a235d9ce5d Mon Sep 17 00:00:00 2001
From: Alessio Emireni <alessio.emireni@gmail.com>
Date: Mon, 10 Jul 2023 15:11:59 +0200
Subject: [PATCH] fix(phone-as-device): app-478 app-479 fix NPE client is non
 connected

---
 README.md                                     |  8 ++++++
 .../reactnative/mqtt/RNMqttClient.kt          | 25 +++++++++++++++++++
 ios/MqttClient.m                              |  2 ++
 ios/MqttClient.swift                          | 25 ++++++++++++++++++-
 package.json                                  |  2 +-
 src/index.tsx                                 | 13 ++++++++++
 6 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index de14d5a..4a44060 100644
--- a/README.md
+++ b/README.md
@@ -128,6 +128,14 @@ To handle messages in the subscribed topic, you have to handle a [`receive-messa
 MqttClient.disconnect();
 ```
 
+### Check if client is connected to an MQTT Broker
+
+`MqttClient.isConnected` checks if client is connected to an MQTT Broker.
+
+```js
+MqttClient.isConnected();
+```
+
 ### Loading an identity
 
 An identity stored in a device specific key store by `MqttClient.setIdentity` may be loaded by `MqttClient.loadIdentity`.
diff --git a/android/src/main/java/com/github/emotokcak/reactnative/mqtt/RNMqttClient.kt b/android/src/main/java/com/github/emotokcak/reactnative/mqtt/RNMqttClient.kt
index 527586a..0e33f50 100644
--- a/android/src/main/java/com/github/emotokcak/reactnative/mqtt/RNMqttClient.kt
+++ b/android/src/main/java/com/github/emotokcak/reactnative/mqtt/RNMqttClient.kt
@@ -537,6 +537,31 @@ class RNMqttClient(reactContext: ReactApplicationContext)
         }
     }
 
+    /**
+     * Determines if this client is currently connected to the server.
+     * Returns: true if connected, false otherwise.
+     *
+     * @param promise
+     *
+     *   Resolved when check connection has done.
+     */
+    @ReactMethod
+    fun isConnected(promise: Promise) {
+        val client = this.client
+        if (client == null) {
+            promise.resolve(false)
+            return
+        }
+        try {
+            val isClientConnected = client.isConnected
+            promise.resolve(isClientConnected)
+        } catch (e: Exception) {
+            Log.e(NAME, "failed to check connection", e)
+            promise.reject("ERROR_CHECK_CONNECTION", e)
+            return
+        }
+    }
+
     // Notifies a `got-error` event.
     private fun notifyError(code: String, cause: Throwable?) {
         val params = Arguments.createMap()
diff --git a/ios/MqttClient.m b/ios/MqttClient.m
index d3e8d93..3876ecf 100644
--- a/ios/MqttClient.m
+++ b/ios/MqttClient.m
@@ -12,6 +12,8 @@ @interface RCT_EXTERN_MODULE(MqttClient, NSObject)
 
 RCT_EXTERN_METHOD(connect:(NSDictionary*)params resolve:(RCTPromiseResolveBlock)resolve reject:(RCTPromiseRejectBlock)reject)
 
+RCT_EXTERN_METHOD(isConnected:(RCTPromiseResolveBlock)resolve reject:(RCTPromiseRejectBlock)reject)
+
 RCT_EXTERN_METHOD(disconnect)
 
 RCT_EXTERN_METHOD(publish:(NSString*)topic payload:(NSArray*)payload resolve:(RCTPromiseResolveBlock)resolve reject:(RCTPromiseRejectBlock)reject)
diff --git a/ios/MqttClient.swift b/ios/MqttClient.swift
index 6493a86..9354a39 100644
--- a/ios/MqttClient.swift
+++ b/ios/MqttClient.swift
@@ -324,7 +324,30 @@ class MqttClient : RCTEventEmitter {
         _ = self.client!.connect()
         resolve(nil)
     }
-
+    
+    @objc(isConnected:reject:)
+    func isConnected(resolve: RCTPromiseResolveBlock, reject: RCTPromiseRejectBlock) -> Void
+    {
+        os_log("MqttClient: isConnected")
+        guard let client = self.client else {
+            resolve(false)
+            return
+        }
+        var isConnected: Bool
+        let connectionState = client.connState
+        switch connectionState {
+        case .connected:
+            isConnected = true
+        case .connecting:
+            isConnected = false
+        case .disconnected:
+            isConnected = false
+        default:
+            isConnected = false
+        }
+        resolve(isConnected)
+    }
+    
     @objc(disconnect)
     func disconnect() -> Void {
         os_log("MqttClient: disconnecting")
diff --git a/package.json b/package.json
index b908970..a8c764a 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "react-native-mqtt-client",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "description": "MQTT client for React Native",
   "main": "lib/commonjs/index",
   "module": "lib/module/index",
diff --git a/src/index.tsx b/src/index.tsx
index 8f3077f..9f0f470 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -182,6 +182,19 @@ export class MqttClient {
     return MqttClientImpl.subscribe(topic);
   }
 
+  /**
+   * Determines if this client is currently connected to the server
+   *
+   * @function isConnected
+   *
+   * @return {Promise<boolean>}
+   *
+   *   Resolved when check connection has done.
+   */
+  isConnected(): Promise<boolean> {
+    return MqttClientImpl.isConnected();
+  }
+
   /**
    * Listens for a given event from this client.
    *