node-red-nodes/99-sample.js.demo

// If you use this as a template, update the copyright with your own name.

// Sample Node-RED node file


module.exports = function(RED) {
    "use strict";
    // require any external libraries we may need....
    //var foo = require("foo-library");

    // The main node definition - most things happen in here
    function SampleNode(n) {
        // Create a RED node
        RED.nodes.createNode(this,n);

        // Store local copies of the node configuration (as defined in the .html)
        this.topic = n.topic;

        // copy "this" object in case we need it in context of callbacks of other functions.
        var node = this;

        // Do whatever you need to do in here - declare callbacks etc
        // Note: this sample doesn't do anything much - it will only send
        // this message once at startup...
        // Look at other real nodes for some better ideas of what to do....
        var msg = {};
        msg.topic = this.topic;
        msg.payload = "Hello world !"

        // send out the message to the rest of the workspace.
        // ... this message will get sent at startup so you may not see it in a debug node.
        this.send(msg);

        // respond to inputs....
        this.on('input', function (msg) {
            node.warn("I saw a payload: "+msg.payload);
            // in this example just send it straight on... should process it here really
            node.send(msg);
        });

        this.on("close", function() {
            // Called when the node is shutdown - eg on redeploy.
            // Allows ports to be closed, connections dropped etc.
            // eg: node.client.disconnect();
        });
    }

    // Register the node by name. This must be called before overriding any of the
    // Node functions.
    RED.nodes.registerType("sample",SampleNode);

}