Convert Mixins to Addons

[pascalwilbrink]

Acceptance Criteria

• [ ] A successful POC Lit of a basic/trivial/example distribution with the simplest Addon (Log) and most complex one (Plugin)
• [ ] Addon definition exists in Glossary
• [ ] Each Addon is available to install
• [ ] Each Addon can be used independently from the others
• [ ] Addon Requirements are defined with documentation
• [ ] Addons depending on different versions of Lit still can work together at runtime

Example Addon Requirements

These are just examples, not a final or even a correct list

• Maximum Size
• Custom Element
• Event dispatch target
• How do Addons provide APIs

Out of Scope

• Documenting how to create a distribution

Notes

• the POC's structure and dependencies on packages needs to be very similar to the real world usage, otherwise we won't find problems like querying over shadow DOM
• core should not depend on Lit (preferrably no dependencies at all, just devDependencies)
• openscd will contain the logic that is needed for implementing API's from core
• OpenSCD class (outer Shell) should extend directly from LitElement

[trusz]

Can we have prioritized list of mixins/addons that eg.: compass needs to create a distribution?

[trusz]

An architecture decision we have to make is how the Addons provide APIs to other Addons and/or Plugins.

[trusz]

An example HTML structure of a distribution in Svelte

[trusz]

a small POC: https://stackblitz.com/edit/vitejs-vite-tbwkqi