How to use Vue in a shadow root with scoped registry

[lennartbuit]

Hey hey,

We have a design system that exports (lit based) custom elements. We also have microfrontends that use Vue. What we are trying to solve is that if a microfrontend depends on component library version 1.x and another on 2.x, that they can live next to eachother.

In the webcomponent world, there is a proposal to add scoped registries. The idea is that per shadow root, you tell what constructor to use for what tag. So in the "old" microfrontend, we'll point to the 1.x version of the component, and in the "new" microfrontend we'll point to the 2.x version of the component.

So we have a little wrapper around a vue component, that registers components for use in vue:

class SomeApp extends ScopedElementsMixin(HTMLElement) {
  static scopedElements = {
    "scoped-button": CustomButton,
  };

  constructor() {
    super();
    this.attachShadow({ mode: "open" });
  }

  connectedCallback() {
    this.app = createApp(App);
    this.app.mount(this.shadowRoot);
  }
}
customElements.define("some-app", SomeApp);

Now, in a scoped registry world, if you set innerHTML, you will automatically use your locally-registered components (and only those!). Thats great, but, when using imperative construction API's, you need to specify for what shadow root you create elements. So, this.shadowRoot.createElement instead of document.createElement.

So, we tried this, we can create a custom (Vue) renderer that has a custom createElement function, that uses this.shadowRoot.createElement. We got that to work. But, to get that to work, we needed to copy the definitions of patchProp and nodeOps from @vue/runtime-dom as they are not exported. Not great.

Would there be a way to amend the default vue renderer with a new createElement function that is aware of these scoped elements?

---

Here is a little project using scoped registry, showing the differences between native web, and Vue: https://codesandbox.io/p/devbox/scoped-elements-l7dd42

[stevenkuster]

Can this get a response?

[BartJanvanAssen]

@yyx990803 You know someone who to get this in there?