Implemented websocket connection with backend on sensors

smart-hut/src/client_server.js

@@ -1,33 +1,149 @@
+// vim: set ts=2 sw=2 et tw=80:
+
 import axios from "axios";
 
 let config = "http://localhost:8080/";
 var tkn = localStorage.getItem("token");
 
+/** the ServiceSocket instance valid for the current session */
+var socket;
+
 // requests data devices
 /*
 
     {
-        params : data,
-        device: 'tipoDiDevice',
-        id: se serve
+  params : data,
+  device: 'tipoDiDevice',
+  id: se serve
     }
 
 
     device routes:
-        - buttonDimmer
-        - dimmableLight
-        - knobDimmer
-        - motionSensor
-        - regularLight
-        - sensor
-        - smartPlug
-        - switch
+  - buttonDimmer
+  - dimmableLight
+  - knobDimmer
+  - motionSensor
+  - regularLight
+  - sensor
+  - smartPlug
+  - switch
 
 */
 
+/** The number of times a connection to the socket was tried */
+var retries = 0;
+
+/** Class to handle connection with the sensor socket */
+class ServiceSocket {
+  /**
+   * Create a new sensor socket connection
+   * @param {string} token - The JWT token (needed for authentication)
+   * @param {Object.<number, function>|null} callbacks - A callback map from
+   *  device id to callback function
+   */
+  constructor(token, callbacks) {
+    this.token = token;
+    this.authenticated = false;
+    this.callbacks = callbacks || {};
+
+    this.connection = new WebSocket("ws://localhost:8080/sensor-socket");
+
+    this.connection.onopen = (evt) => {
+      this.connection.send(JSON.stringify({ token }));
+    };
+
+    this.connection.onmessage = (evt) => {
+      let data = JSON.parse(evt.data);
+
+      if (!this.authenticated) {
+        if (data.authenticated) {
+          this.authenticated = true;
+          retries = 0;
+        } else {
+          console.error("socket authentication failed");
+        }
+      } else {
+        if (data.id && this.callbacks[data.id]) {
+          this.callbacks[data.id].forEach((f) => f(data));
+        }
+      }
+    };
+
+    this.connection.onerror = (evt) => {
+      if (retries >= 5) {
+        console.error("too many socket connection retries");
+        return;
+      }
+      retries++;
+      socket = new ServiceSocket(this.token, this.callbacks);
+    };
+  }
+
+  /**
+   * Registers a new callback function to be called when updates on the device
+   * with the id given are recieved
+   * @param {number} id - the id of the device to check updates for
+   * @param {function} stateCallback - a function that recieves a device as the
+   *  first parameter, that will be called whenever a update is recieved
+   */
+  subscribe(id, stateCallback) {
+    if (this.callbacks[id] === undefined) {
+      this.callbacks[id] = [];
+    }
+
+    this.callbacks[id].push(stateCallback);
+  }
+
+  /**
+   * Unregisters a function previously registered with `subscribe(...)`.
+   * @param {number} id - the id of the device to stop checking updates for
+   * @param {function} stateCallback - the callback to unregister
+   */
+  unsubscribe(id, stateCallback) {
+    this.callbacks[id].splice(this.callbacks[id].indexOf(stateCallback), 1);
+  }
+
+  /**
+   * Closes the underlying websocket connection
+   */
+  close() {
+    this.connection.close();
+  }
+}
+
+if (tkn) {
+  socket = new ServiceSocket(tkn);
+}
+
 export var call = {
   setToken: function (token) {
     tkn = token;
+    if (tkn) {
+      if (socket) {
+        socket.close();
+      }
+      socket = new ServiceSocket(tkn);
+    }
+  },
+
+  /**
+   * Registers a new callback function to be called when updates on the device
+   * with the id given are recieved
+   * @param {number} id - the id of the device to check updates for
+   * @param {function} stateCallback - a function that recieves a device as the
+   *  first parameter, that will be called whenever a update is recieved
+   */
+  socketSubscribe: function (id, callback) {
+    socket.subscribe(id, callback);
+  },
+
+  /**
+   * Unregisters a function previously registered with `subscribe(...)`.
+   * @param {number} id - the id of the device to stop checking updates for
+   * @param {function} stateCallback - the callback to unregister
+   */
+  socketUnsubscribe: function (id, callback) {
+    socket.unsubscribe(id, callback);
   },
   login: function (data, headers) {
     return axios.post(config + "auth/login", data);

smart-hut/src/components/dashboard/DevicePanel.js

@@ -1,3 +1,5 @@
+// vim: set ts=2 sw=2 et tw=80:
+
 import React, { Component } from "react";
 import { Grid } from "semantic-ui-react";
 import { editButtonStyle, panelStyle } from "./devices/styleComponents";

smart-hut/src/components/dashboard/devices/Sensor.js

@@ -28,6 +28,7 @@ import {
 import { sensorText, style, valueStyle } from "./SensorStyle";
 import Settings from "./DeviceSettings";
 import { StyledDiv } from "./styleComponents";
+import { call } from "../../../client_server";
 
 export default class Sensor extends Component {
   constructor(props) {
@@ -37,6 +38,13 @@ export default class Sensor extends Component {
       value: 0,
     };
     this.units = "";
+    this.stateCallback = (e) => this.setState(Object.assign(this.state, e));
+
+    call.socketSubscribe(this.props.device.id, this.stateCallback);
+  }
+
+  componentWillUnmount() {
+    call.socketUnsubscribe(this.props.device.id, this.stateCallback);
   }
 
   setName = () => {