Drop support for multiple connections

Author: xowor

README.md

@@ -24,48 +24,48 @@ import ArduinoCloud from 'arduino-iot-js';
 //   apiUrl: 'AUTH SERVER URL', // Default is https://auth.arduino.cc
 //   onDisconnect: message => { /* Disconnection callback */ }
 // }
-ArduinoCloud.connect(options).then(connectionId => {
+ArduinoCloud.connect(options).then(() => {
   // Connected
 });
 
-ArduinoCloud.disconnect(connectionId).then(() => {
+ArduinoCloud.disconnect().then(() => {
   // Disconnected
 });
 
-ArduinoCloud.subscribe(connectionId, topic, cb).then(topic => {
+ArduinoCloud.subscribe(topic, cb).then(topic => {
   // Subscribed to topic, messaged fired in the cb
 });
 
-ArduinoCloud.unsubscribe(connectionId, topic).then(topic => {
+ArduinoCloud.unsubscribe(topic).then(topic => {
   // Unsubscribed to topic
 });
 
-ArduinoCloud.sendMessage(connectionId, topic, message).then(() => {
+ArduinoCloud.sendMessage(topic, message).then(() => {
   // Message sent
 });
 
-ArduinoCloud.openCloudMonitor(connectionId, deviceId, cb).then(topic => {
+ArduinoCloud.openCloudMonitor(deviceId, cb).then(topic => {
   // Cloud monitor messages fired to cb
 });
 
-ArduinoCloud.writeCloudMonitor(connectionId, deviceId, message).then(() => {
+ArduinoCloud.writeCloudMonitor(deviceId, message).then(() => {
   // Message sent to cloud monitor
 });
 
-ArduinoCloud.closeCloudMonitor(connectionId, deviceId).then(topic => {
+ArduinoCloud.closeCloudMonitor(deviceId).then(topic => {
   // Close cloud monitor
 });
 
 // Send a property value to a device
 // - value can be a string, a boolean or a number
 // - timestamp is a unix timestamp, not required
-ArduinoCloud.sendProperty(connectionId, thingId, name, value, timestamp).then(() => {
+ArduinoCloud.sendProperty(thingId, name, value, timestamp).then(() => {
   // Property value sent
 });
 
 // Register a callback on a property value change
 // 
-ArduinoCloud.onPropertyValue(connectionId, thingId, propertyName, updateCb).then(() => {
+ArduinoCloud.onPropertyValue(thingId, propertyName, updateCb).then(() => {
   // updateCb(message) will be called every time a new value is available. Value can be string, number, or a boolean depending on the property type
 });
 

src/index.js

@@ -48,7 +48,7 @@ import CBOR from 'cbor-js';
 
 import ArduinoCloudError from './ArduinoCloudError';
 
-const connections = {};
+let connection = null;
 const subscribedTopics = {};
 const propertyCallback = {};
 const arduinoCloudPort = 8443;
@@ -82,6 +82,10 @@ const connect = options => new Promise((resolve, reject) => {
     onConnected: options.onConnected,
   };
 
+  if (connection) {
+    return reject(new Error('connection failed: connection already open'));
+  }
+
   if (!opts.host) {
     return reject(new Error('connection failed: you need to provide a valid host (broker)'));
   }
@@ -140,10 +144,8 @@ const connect = options => new Promise((resolve, reject) => {
       if (reconnect === true) {
         // This is a re-connection: re-subscribe to all topics subscribed before the
         // connection loss
-        Object.getOwnPropertySymbols(subscribedTopics).forEach((connectionId) => {
-          Object.values(subscribedTopics[connectionId]).forEach((subscribeParams) => {
-            subscribe(connectionId, subscribeParams.topic, subscribeParams.cb);
-          });
+        Object.values(subscribedTopics).forEach((subscribeParams) => {
+          subscribe(subscribeParams.topic, subscribeParams.cb);
         });
       }
 
@@ -170,9 +172,8 @@ const connect = options => new Promise((resolve, reject) => {
       reconnect: true,
       keepAliveInterval: 30,
       onSuccess: () => {
-        const id = Symbol(clientID);
-        connections[id] = client;
-        return resolve(id);
+        connection = client;
+        return resolve();
       },
       onFailure: ({ errorCode, errorMessage }) => reject(
         new ArduinoCloudError(errorCode, errorMessage),
@@ -192,20 +193,19 @@ const connect = options => new Promise((resolve, reject) => {
   }, reject);
 });
 
-const disconnect = id => new Promise((resolve, reject) => {
-  const client = connections[id];
-  if (!client) {
-    return reject(new Error('disconnection failed: client not found'));
+const disconnect = () => new Promise((resolve, reject) => {
+  if (!connection) {
+    return reject(new Error('disconnection failed: connection closed'));
   }
 
   try {
-    client.disconnect();
+    connection.disconnect();
   } catch (error) {
     return reject(error);
   }
 
   // Remove the connection
-  delete connections[id];
+  connection = null;
 
   // Remove property callbacks to allow resubscribing in a later connect()
   Object.keys(propertyCallback).forEach((topic) => {
@@ -215,35 +215,36 @@ const disconnect = id => new Promise((resolve, reject) => {
   });
 
   // Clean up subscribed topics - a new connection might not need the same topics
-  delete subscribedTopics[id];
+  Object.keys(subscribedTopics).forEach((topic) => {
+    delete subscribedTopics[topic];
+  });
+
   return resolve();
 });
 
-const subscribe = (id, topic, cb) => new Promise((resolve, reject) => {
-  const client = connections[id];
-  if (!client) {
-    return reject(new Error('subscription failed: client not found'));
+const subscribe = (topic, cb) => new Promise((resolve, reject) => {
+  if (!connection) {
+    return reject(new Error('subscription failed: connection closed'));
   }
 
-  return client.subscribe(topic, {
+  return connection.subscribe(topic, {
     onSuccess: () => {
-      if (!client.topics[topic]) {
-        client.topics[topic] = [];
+      if (!connection.topics[topic]) {
+        connection.topics[topic] = [];
       }
-      client.topics[topic].push(cb);
+      connection.topics[topic].push(cb);
       return resolve(topic);
     },
     onFailure: () => reject(),
   });
 });
 
-const unsubscribe = (id, topic) => new Promise((resolve, reject) => {
-  const client = connections[id];
-  if (!client) {
-    return reject(new Error('disconnection failed: client not found'));
+const unsubscribe = topic => new Promise((resolve, reject) => {
+  if (!connection) {
+    return reject(new Error('disconnection failed: connection closed'));
   }
 
-  return client.unsubscribe(topic, {
+  return connection.unsubscribe(topic, {
     onSuccess: () => resolve(topic),
     onFailure: () => reject(),
   });
@@ -260,32 +261,31 @@ const arrayBufferToBase64 = (buffer) => {
   return window.btoa(binary);
 };
 
-const sendMessage = (id, topic, message) => new Promise((resolve, reject) => {
-  const client = connections[id];
-  if (!client) {
-    return reject(new Error('disconnection failed: client not found'));
+const sendMessage = (topic, message) => new Promise((resolve, reject) => {
+  if (!connection) {
+    return reject(new Error('disconnection failed: connection closed'));
   }
 
-  client.publish(topic, message, 1, false);
+  connection.publish(topic, message, 1, false);
   return resolve();
 });
 
-const openCloudMonitor = (id, deviceId, cb) => {
+const openCloudMonitor = (deviceId, cb) => {
   const cloudMonitorOutputTopic = `/a/d/${deviceId}/s/o`;
-  return subscribe(id, cloudMonitorOutputTopic, cb);
+  return subscribe(cloudMonitorOutputTopic, cb);
 };
 
-const writeCloudMonitor = (id, deviceId, message) => {
+const writeCloudMonitor = (deviceId, message) => {
   const cloudMonitorInputTopic = `/a/d/${deviceId}/s/i`;
-  return sendMessage(id, cloudMonitorInputTopic, message);
+  return sendMessage(cloudMonitorInputTopic, message);
 };
 
-const closeCloudMonitor = (id, deviceId) => {
+const closeCloudMonitor = (deviceId) => {
   const cloudMonitorOutputTopic = `/a/d/${deviceId}/s/o`;
-  return unsubscribe(id, cloudMonitorOutputTopic);
+  return unsubscribe(cloudMonitorOutputTopic);
 };
 
-const sendProperty = (connectionId, thingId, name, value, timestamp) => {
+const sendProperty = (thingId, name, value, timestamp) => {
   const propertyInputTopic = `/a/t/${thingId}/e/i`;
 
   if (timestamp && !Number.isInteger(timestamp)) {
@@ -315,7 +315,7 @@ const sendProperty = (connectionId, thingId, name, value, timestamp) => {
       break;
   }
 
-  return sendMessage(connectionId, propertyInputTopic, CBOR.encode([cborValue]));
+  return sendMessage(propertyInputTopic, CBOR.encode([cborValue]));
 };
 
 const getSenml = (deviceId, name, value, timestamp) => {
@@ -357,7 +357,7 @@ const getCborValue = (senMl) => {
   return arrayBufferToBase64(cborEncoded);
 };
 
-const sendPropertyAsDevice = (connectionId, deviceId, thingId, name, value, timestamp) => {
+const sendPropertyAsDevice = (deviceId, thingId, name, value, timestamp) => {
   const propertyInputTopic = `/a/t/${thingId}/e/o`;
 
   if (timestamp && !Number.isInteger(timestamp)) {
@@ -369,10 +369,10 @@ const sendPropertyAsDevice = (connectionId, deviceId, thingId, name, value, time
   }
 
   const senMlValue = getSenml(deviceId, name, value, timestamp);
-  return sendMessage(connectionId, propertyInputTopic, CBOR.encode([senMlValue]));
+  return sendMessage(propertyInputTopic, CBOR.encode([senMlValue]));
 };
 
-const onPropertyValue = (connectionId, thingId, name, cb) => {
+const onPropertyValue = (thingId, name, cb) => {
   if (!name) {
     throw new Error('Invalid property name');
   }
@@ -381,19 +381,15 @@ const onPropertyValue = (connectionId, thingId, name, cb) => {
   }
   const propOutputTopic = `/a/t/${thingId}/e/o`;
 
-  if (!subscribedTopics[connectionId]) {
-    subscribedTopics[connectionId] = {};
-  }
-
-  subscribedTopics[connectionId][thingId] = {
+  subscribedTopics[thingId] = {
     topic: propOutputTopic,
     cb,
   };
 
   if (!propertyCallback[propOutputTopic]) {
     propertyCallback[propOutputTopic] = {};
     propertyCallback[propOutputTopic][name] = cb;
-    subscribe(connectionId, propOutputTopic, cb);
+    subscribe(propOutputTopic, cb);
   } else if (propertyCallback[propOutputTopic] && !propertyCallback[propOutputTopic][name]) {
     propertyCallback[propOutputTopic][name] = cb;
   }