node-red-contrib-axis-host/axis-events.js

Axis Devices resource binding nodes that provides access to events, image capture and analytics data. Node-RED must be running on the Axis Device.

//Copyright (c) 2023 Fred Juhlin

const { spawn } = require('child_process');

module.exports = function(RED) {
	
    function AXIS_Events(config) {
		RED.nodes.createNode(this,config);
		this.group = config.group;
		this.initialization = config.initialization;
		var node = this;
		var suppress = false;

		if( node.initialization ) {
			suppress = true;
			setTimeout(function(){
				suppress = false;
			}, 5000);
		}

        const eventlistner = spawn('eventlistener');
		node.status({fill:"green",shape:"dot",text:"Running"});

        eventlistner.stdout.on('data', (data) => {
			if( suppress )
				return;
			
			var rows = data.toString().split("\n");
			var topic0 = null;
			var topic1 = null;
			var topic2 = null;
			var topic3 = null;
			var payload = {};
			
			for( var i = 0; i < rows.length; i++) {

				var row = rows[i].substr(27);
				row = row.replace(/'/g,"");
				
				if (row.search('- Event -') >= 0 ){ //New event
					topic0 = null;
					topic1 = null;
					topic2 = null;
					topic3 = null;
					payload = {};
					continue;
				}

				if (row.search('-------------------------') >= 0) {
					var send = true;
					if(topic0 && topic1 ) {
						var topic = topic0 + "/" + topic1;
						if( topic2 ) {
							topic += "/" + topic2;
							if( topic2 === "xinternal_data" )
								send = false;
						}
						if (topic3)
							topic += "/" + topic3;
						//Ignore events
						if( node.group !== "All events" && topic.search(node.group) < 0 )
							send = false

						if( send && topic0 === "audiocontrol")
							send = false; 

						if( send )
							node.send({
								topic: topic,
								payload: payload
							});
					}
					continue;
				}
				
				var brackets = row.match(/\[(.*?)\]/);
				var bracket = (brackets && brackets.length > 0) ? brackets[1]:null;

				if(!bracket)
					continue;

//				node.warn(bracket);
				if (bracket.search("topic0") >= 0) {
					topic0 = bracket.split(" = ")[1].split(" ")[0].toLowerCase();
					continue;
				}
				if (bracket.search("topic1") >= 0) {
					topic1 = bracket.split(" = ")[1].split(" ")[0].toLowerCase();
					continue;
				}
				if (bracket.search("topic2") >= 0) {
					topic2 = bracket.split(" = ")[1].split(" ")[0].toLowerCase();
					continue;
				}
				if (bracket.search("topic3") >= 0) {
					topic3 = bracket.split(" = ")[1].split(" ")[0].toLowerCase();
					continue;
				}

				var items = bracket.split(' = ');
				if(items.length !== 2 )
					continue;

				var property = items[0].split(" ")[0].replace(/[^\w\s]/g, '').toLowerCase();
				var value = items[1];

				//Make number and cleanup
				if( isNaN(value) === false )
					value = parseInt(value);

				//Make boolean
				if (property === "active")
					value = value !== 0;
				if (property === "state")
					value = value !== 0;
				if (property === "ready")
					value = value !== 0;
				if (property === "failed")
					value = value !== 0;
				if (property === "connected")
					value = value !== 0;
				if (property === "day")
					value = value !== 0;
				if (property === "running")
					value = value !== 0;
				if (property === "disruption")
					value = value !== 0;
				if (property === "logicalstate") {
					property = "state";
					value = value !== 0;
				}
				if( value === "Yes" )
					value = true;
				if( value === "No" )
					value = false;

				//Remove properties
				if (property === "relaytoken")
					continue;
				if (property === "inputtoken")
					continue;
				if (property === "videosourceconfigurationtoken")
					continue;
				if (property === "diskmountpoint")
					continue;
				payload[property] = value;
			}
        });

        eventlistner.on('error', (error) => {
            node.error("Events not avaialble",{payload:"Unable to locate service"});
			node.status({fill:"red",shape:"dot",text:"Stopped"});
        });

        eventlistner.stderr.on('data', (data) => {
            node.error("Device Event error",{topic:"Error",payload:data.toString()} );
        });

        eventlistner.on('close', (code) => {
			if( restart ) {
				setTimeout(function(){
					eventlistner = spawn('eventlistener');
					node.warn("Events restarted",{payload:"Process exited with code " + code});
				},2000);
			}
        });

        node.on('close', (done) => {
			restart = false;
			node.status({fill:"red",shape:"dot",text:"Stopped"});
            if (eventlistner) {
                eventlistner.kill(); // Terminate the child process
            }
            done();
        });
    }
	
    RED.nodes.registerType("Events",AXIS_Events,{
		defaults: {
			group: { type:"text" },
			initialization: { type:"boolean" }
		}		
	});
}