Prevent attempted double registration of the web-component

[davidsneighbour]

lite-youtube-embed/src/lite-yt-embed.js

Line 239 in 1b88628

customElements.define('lite-youtube', LiteYTEmbed);

Adding the script more than once results in browser console errors

youtube/:7699 Uncaught NotSupportedError: Failed to execute 'define' on 'CustomElementRegistry': the name "lite-youtube" has already been used with this registry

The component JS always runs customElements.define() instead of checking, if the component is already defined, using for instance.

if (!customElements.get('lite-youtube')) {
  customElements.define('lite-youtube', LiteYTEmbed);
} else {
  // do nothing or print a nice warning
}

While it is better to instantiate this right away correctly, people might attempt to add the script twice per site or even once per embed if used multiple times per page. Checking if it's already defined would silence the browser console.