HTML Setters Polyfill

A polyfill for new HTML setters (streamHTML, appendHTML... etc. and unsafe variants) as proposed in WHATWG HTML issue #11669.

Features

• Insertion variants: setHTML, beforeHTML, afterHTML on Element and ShadowRoot.
• Child insertion variants: replaceWithHTML, prependHTML, appendHTML on nodes with children.
• Insertion Unsafe variants: setHTMLUnsafe, appendHTMLUnsafe, prependHTMLUnsafe, beforeHTMLUnsafe, afterHTMLUnsafe, replaceWithHTMLUnsafe.
• Streaming variants: steamHTML, streamHTMLUnsafe, streamBeforeHTML...etc. return a WritableStream that buffers and applies the HTML on close.
• Supports runScripts: true using createContextualFragment.
• JSDoc types for TypeScript compatibility in JS.
• No dependencies.
• No Trusted Types support on streaming.

Usage

// Set HTML unsafe
element.setHTMLUnsafe('<div><script>console.log("hi")</script></div>', { runScripts: true });

// Stream HTML
const stream = element.streamHTMLUnsafe({ runScripts: true });
const writer = stream.getWriter();
writer.write('<div>Hello ');
writer.write('World!</div>');
writer.close();

Limitations

• Streaming is not natively "streamed" to the parser (it buffers first).
• Safe streaming is only supported if setHTML is supported in the target browser (i.e. not Safari).
• Declarative Shadow DOM (DSD) is supported if createContextualFragment supports it in the target browser.

License

Apache 2.0

Contributing

We'd love to accept your patches and contributions to this project. See the enclosed CONTRIBUTING.md for details.

Disclaimer

This is not an officially supported Google product. This project is not eligible for the Google Open Source Software Vulnerability Rewards Program.