openwebrxplus-plugins

This plugin is a reference for developers. It is not meant to be loaded — the file starts with a throw to prevent accidental use. Read the source as a cookbook.

New Developer Quickstart

1. Create your plugin folder and file

htdocs/plugins/receiver/my_plugin/my_plugin.js

The folder name and JS filename must match exactly. The plugin loader derives the plugin name from both.

2. Minimal plugin skeleton

/*
 * my_plugin - short description
 *
 * License: MIT
 * Copyright (c) 2025 Your Name
 */

// Tell the loader there is no CSS file for this plugin.
// Remove this line if you ship a my_plugin.css alongside the JS.
Plugins.my_plugin.no_css = true;

// Declare a version so other plugins can check for it with Plugins.isLoaded().
Plugins.my_plugin._version = 0.1;

// The loader calls init() after the JS is fetched.
// Return true on success, false to signal a failed dependency check.
Plugins.my_plugin.init = function () {

  // Dependency check — remove if you don't need utils.
  if (!Plugins.isLoaded('utils', 0.1)) {
    console.error('my_plugin requires utils >= 0.1');
    return false;
  }

  console.log('my_plugin loaded!');
  return true;
};

3. Load it locally in `init.js`

// Load utils first (required dependency for most plugins)
await Plugins.load('https://0xaf.github.io/openwebrxplus-plugins/receiver/utils/utils.js');

// Load your local plugin by folder name (no URL needed for local plugins)
await Plugins.load('my_plugin');

4. Iterate

Open the browser console (F12) to see console.log / console.error output.
Set Plugins._enable_debug = true; in init.js for verbose loader output.
Set Plugins.utils._DEBUG_ALL_EVENTS = true; to log every OWRX+ event.

Patterns shown in `example.js`

Listening to events (read-only)

Use $(document).on('event:name', callback) to react to events. You cannot modify the data from here — for that, wrap the source function instead (see below).

$(document).on('event:profile_changed', function (e, data) {
  console.log('profile changed to:', data);
});

Useful events fired by the utils plugin:

Event	When
`event:profile_changed`	User switches SDR profile
`server:config:before` / `:after`	Server sends configuration
`server:bookmarks:before` / `:after`	Server sends bookmarks
`server:profiles:before` / `:after`	Server sends profile list
`server:features:before` / `:after`	Server sends feature flags
`server:clients:before` / `:after`	Client count changes

All server:* events carry the message value as the second argument to the callback.

Wrapping an existing OWRX+ function

Use Plugins.utils.wrap_func() to intercept any global function. The before_cb runs first and controls whether the original is called. The after_cb runs after and can replace the return value.

Plugins.utils.wrap_func(
  'sdr_profile_changed',          // name of the global function to wrap
  function (orig, thisArg, args) { // before callback
    console.log('about to change profile');
    return true;                  // return true to let the original run
  },
  function (res, thisArg, args) { // after callback
    console.log('profile changed');
    return res;                   // return res (or a replacement value)
  }
);

Return false from before_cb to block the original call (and skip after_cb). If you call orig.apply(thisArg, args) yourself inside before_cb, also return false to prevent a second call.

Wrapping a function that only exists after OWRX+ initialises

Some objects (e.g. bookmarks) are created during page init, not at load time. Wait for the ready signal before wrapping them:

Plugins.utils.on_ready(function () {
  Plugins.utils.wrap_func('replace_bookmarks',
    function (orig, thisArg, args) {
      // args[0] is the bookmark array, args[1] is the source ('server'|'client')
      if (args[1] === 'server' && Array.isArray(args[0]) && args[0].length) {
        args[0][0].name = 'replaced';
      }
      orig.apply(thisArg, args);
      return false; // we called orig ourselves, prevent a second call
    },
    function () { /* skipped */ },
    bookmarks  // pass the object that owns the function
  );
});

Useful DOM selectors and globals

What	Selector / variable
Receiver panel	`#openwebrx-panel-receiver`
Profile dropdown	`#openwebrx-sdr-profiles-listbox`
Theme dropdown	`#openwebrx-themes-listbox`
Current profile ID	`currentprofile` (global)
Center frequency (Hz)	`center_freq` (global)
Demodulator object	`$("#openwebrx-panel-receiver").demodulatorPanel().getDemodulator()`

Shipping a CSS file

Drop a my_plugin.css next to my_plugin.js. The loader fetches it automatically after the JS unless Plugins.my_plugin.no_css = true is set.