IE11 support

[Thibaud Colas]

Initially reported in #7. The conditional fields don’t work for me in IE11. There is ES6+ syntax used in the published code, which creates a syntax error in IE11:

class TbxForms {
  static selector() {
    return "form.tbxforms";
  }

It looks like Vite (esbuild) unfortunately doesn’t support compiling down to ES5 (what we’d need for IE11 compatibility), the build.target only goes down to es2015 (ES6).

The simplest way to fix this would be to rewrite the JS code to not use the class syntax (which isn’t that good to start with, and doesn’t do much for this project – just make a function initTbxForms(node) {}, and a separate clearInput function. I think this should work as long as esbuild doesn’t do any minification. We’ll need to make sure no other part of the code uses ES6+ syntax either (template literals, arrow functions, const, etc.).

Alternatively – we could switch over to Babel for the production build. For a single file like this, the setup is very straightforward with Rollup. See for example https://github.com/thibaudcolas/draftjs-filters/blob/main/rollup.config.js.

Note due to this I haven’t been able to test the things I was worried about initially (dispatchEvent).