cast.js

// Sample Platypush user script to cast the current tab or any media item selected
// on the page to the default Chromecast device configured in Platypush.
async (app, args) => {
  const baseURL = await app.getURL();

  // Default URL to cast: current page URL
  let url = baseURL;

  if (args.target) {
    // The user executed the action from a context menu
    const target = app.HTML2DOM(args.target);

    // If it's a <video> or <audio> HTML element then it will have a <source> tag
    const src = target.querySelector('source');

    // Otherwise, check if it's a link
    const link = target.tagName.toLowerCase() === 'a' ? target : target.querySelector('a');

    if (src) {
      url = src.attributes.src.value;
    } else if (link) {
      url = link.attributes.href.value;
    }
  }

  // Resolve relative URLs
  if (!url.match('^https?://[^/]+') && !url.startsWith('magnet:?')) {
    url = baseURL.match('(^https?://[^/]+)')[1] + (url || '');
  }

  // Finally, cast the media
  await app.run({
    action: 'media.chromecast.play',
    args: {
      resource: url,
    }
  }, args.host);
}