node-red-contrib-trigger-empty/trigger-empty.js

Sends On on input of an On trigger, and when for all On triggers an Off was received off, Send Off

module.exports = function(RED) {
    function TriggerOnEmptyNode(config) {
        RED.nodes.createNode(this,config);
        this.topic = config.topic;
        this.on_payload = config.on_payload;
        this.off_payload = config.off_payload;
        var node = this;
        var triggers = {};
        node.on('input', function(msg) {
            if (typeof msg.topic != "undefined" && typeof msg.payload != "undefined") {
               if(msg.payload.toUpperCase() == this.on_payload.toUpperCase()) {
                  triggers[msg.topic] = this.on_payload;
                  msg.payload = this.on_payload;
                  msg.topic = node.topic;
                  this.status({fill:"green",shape:"dot",text:this.on_payload+" send:"+triggers.keys().length});
                  node.send(msg);
               } else 
               if(msg.payload.toUpperCase() == this.off_payload.toUpperCase()) {
                  delete triggers[msg.topic];
                  if (Object.keys(triggers).length == 0) {
                     msg.payload = this.off_payload;
                     msg.topic = node.topic
                     this.status({fill:"green",shape:"ring",text:this.off_payload+" send:"+triggers.keys().length});
                     node.send(msg);
                  }
               } 
            }
        });
    }
    RED.nodes.registerType("trigger-empty",TriggerOnEmptyNode);
}