sumorobot-web/assets/js/sumorobot.js

// Sumorobot constructor
var Sumorobot = function(wsUri, robotId) {
    // Assign the WebSocket URI
    this.wsUri = wsUri;
    // Assign the SumoRobot ID
    this.robotId = robotId;
    // To keep track of the WebSocket connection
    this.watchdogTimer = 0;
    // Timer to ping the SumoRobot
    this.watchdogTimer = null;
    // To store Blockly code
    this.blocklyCode = "";
    // Start connecting to the WebSocket
    this.connect();
};

// Function to initiate the WebSocket connection
Sumorobot.prototype.connect = function() {
    // To have access to this object inside events
    var self = this;
    this.websocket = new WebSocket(this.wsUri);
    // Setup connection watchdog interval
    setInterval(function() {
        if (self.watchdogCounter == 0) {
            $("#battery").removeClass("connected");
            $("#battery").html("Disconnected");
        }
        // Reset watchdog counter
        self.watchdogCounter = 0;
    }, 3000);
    // When the WebSocket gets connected
    this.websocket.onopen = function(evt) {
        // Send authentication packet
        self.websocket.send(`{"setID": "browser-${self.robotId}@00000514", "passwd": "salakala"}`);
        // Setup a timer to ping the robot
        self.watchdogTimer = setInterval(function() {
            // Send a ping to the robot
            self.send(self.robotId, "ping");
        }, 500);
    };
    // When the WebSocket closes
    this.websocket.onclose = function(evt) {
        // Clear the pinging
        clearInterval(self.watchdogTimer);
        // Try to recnnect to the sumorobot
        self.connect();
    };
    // When there is a message from the WebSocket
    this.websocket.onmessage = function(evt) {
        // When scope is received
        var data = evt.data.replace(/'/g, '"').toLowerCase();
        // Get SumoRobot battery voltage
        var battery = JSON.parse(data)["battery_voltage"];
        // When sensor data received
        if (battery) {
            $("#battery").html(battery + "V");
            $("#battery").addClass("connected");
        }
        // Count data received packets
        self.watchdogCounter += 1;
    };
    // When there is an WebSocket error
    this.websocket.onerror = function(err) {
        console.log("ERROR websocket error: " + err);
    };
};

// Function to send WebSocket data
Sumorobot.prototype.send = function(msg, val) {
    // Ready state constants: CONNECTING 0, OPEN 1, CLOSING 2, CLOSED 3
    // https://developer.mozilla.org/en-US/docs/Web/API/WebSocket
    if (this.websocket.readyState == 1) {
        if (val === 'undefined') {
            this.websocket.send(`{"to": "sumo-${this.robotId}@00000514", "cmd": "${msg}"}`);
        } else {
            this.websocket.send(`{"to": "sumo-${this.robotId}@00000514", "cmd": "${msg}", "val": "${val}"}`);
        }
    }
};

// Function to close the WebSocket connection
Sumorobot.prototype.close = function() {
    // When a WebSocket connection exists
    if (this.websocket !== 'undefined') {
        // Close the WebSocket connection
        this.websocket.close();
    }
};

// Function to get SumoRobot Blockly code
Sumorobot.prototype.getBlocklyCode = function() {
    return this.blocklyCode;
};

// Function to set SumoRobot Blockly code
Sumorobot.prototype.setBlocklyCode = function(blocklyCode) {
    this.blocklyCode = blocklyCode;
};