Custom Elements w/out Builtin for IE11+ and legacy.

Social Media Photo by Joanna Kosinska on Unsplash

A customElements polyfill, without builtin extends, targeting IE11+ and other legacy browsers.

• to add builtin extends, add custom-elements-builtin on demand
• for full V1 API compliance, ditch this module and use custom-elements instead
• for even more legacy browsers, ditch this module and use document-register-element instead

How To Test

Please use features detection to avoid including this polyfill in every browser, considering that this replaces native customElements, if present, so that it would add unnecessary code to parse and execute in every browser that supports Custom Elements builtin natively already.

<script>
if(!self.customElements)
  document.write('<script src="//unpkg.com/@webreflection/custom-elements-no-builtin"><\x2fscript>')
</script>

P.S. the \x2f is not a typo, it's exactly how you should write it or your page layout will break!

To Keep In Mind

This is not a ShadowDOM polyfill, this is just the current Custom Elements V1 as specified by standard bodies without builtin extends.