cssAudio - Activefile-genericCSS - ActiveGeneric - ActiveHTML - ActiveImage - ActiveJS - ActiveSVG - ActiveText - Activefile-genericVideo - ActiveLovehtmlicon-new-collectionicon-personicon-teamlog-outoctocatpop-outspinnerstartv

Pen Settings

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

Quick-add: + add another resource

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

Quick-add: + add another resource

Code Indentation


Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

              // --------------------------------
// Note: to make the DevToolAddon work, please make sure you access this codepen page through 'http' instead of 'https':
// https://codepen.io/bhou/pen/JbgprG

// ---------
// Please follow the steps to debug this app with collar dev tool
// 1. install collar-dev-server
// sudo npm install collar-dev-server
// 2. run collar-dev-server, type following command line:
// collar-dev-server
// 3. open http://localhost:7500
// 4. run this app
// 5. right click "delegate to double module" node, and select "show delegation"

collar.use(new DevToolAddon()) // comment this in production

// First, let's build a pipeline to double the input value
// and use "to" method to connect nodes as a pipeline
const ns1 = collar.ns('namespace1', {module: 'double'});
const filter = ns1.when('test "to" connection', s => {
  return s.get('value') % 2 === 0
const double = ns1.map('double the input value', s => {
  return s.new({    // use signal.new to create a new signal
    value: s.get('value') * 2
const log = ns1.do('log the signal', s => {


// Now create a host module to use the double module
// and use "through" method to delegate the processing
const ns2 = collar.ns('namespace2', {module: 'host'});
const filter2 = ns2.when('test "through" connection', s => {
  return s.get('value') % 2 === 0
const log2 = ns2.do('log the signal', s => {

  .through('delegate to double module', filter, log)

// You should see two pipelines on collar dev tool (http://localhost:7500),
// right click the "delegate to double module" node, and select "show delegation"

Loading ..................