node_helper.js

var NodeHelper = require("node_helper");
const exec = require('child_process').exec;
const fs = require('fs');
const Gpio = require('onoff').Gpio;

var commandDict = {
    "js": "node",
    "py": "python",
    "sh": "sh"
};

module.exports = NodeHelper.create({

    running: false,

    socketNotificationReceived: function (notification, payload) {
        const self = this;
        if (notification === "CONFIG") {
            this.config = payload;
            this.pir = new Gpio(this.config.sensorPin, 'in', 'both');

            this.pir.watch(function (err, value) {
                if (value == 1) {
                    self.sendSocketNotification("USER_PRESENCE", true);
                    if (!self.running) {
                        self.running = true;
                        if (self.config.turnOffDisplay) {
                            execute(buildCommand("/default/displayOn.sh"), function (stdout) {
                                console.log(stdout);
                            });
                        }
                    }
                }
            });
        } else if (notification === "TIMER_EXPIRED") {
            self.running = false;
            for (var i = 0; i < this.config.callbackScripts.length; i++) {
                execute(buildCommand(this.config.callbackScripts[i]), function (stdout) {
                    console.log(stdout);
                });
            }
            if (self.config.turnOffDisplay) {
                execute(buildCommand("/default/displayOff.sh"), function (stdout) {
                    console.log(stdout);
                });
            }
        }
    },


});

function buildCommand(fileName) {
    var file = __dirname + "/callbackScripts/" + fileName;
    var fileExtension = file.split(".").slice(-1).pop();
    return commandDict[fileExtension] + " " + file;
}

function execute(command, callback) {
    exec(command, function (error, stdout, stderr) {
        if (error) {
            console.log(stderr);
        } else {
            callback(stdout);
        }
    });
}