The component registry (`registry.ts` module) holds a mapping of component names to their respective type. e.g. `"Button"` -> `Button`.

This is needed since Angular templates on the one hand are plain strings (that get parsed), and on the other `React.createElement` relies on types to know what components to create (or strings, for native HTML elements).

## Registration

Each React component that should be renderer-able needs to be registered in the component registry by calling the `registerElement(elementName, resolver)` function.

This is usually done in Wrapper libraries' individual `NgModule`s's `constructor`:

```typescript
export class FabCheckboxModule {
  constructor() {
    registerElement('Checkbox', () => Checkbox);
  }
}
```

The `registerElement` function can be called multiple times. Any call to an already-registered `elementName` is discarded, for simplicity's sake with Angular and lazy-loaded modules. See the docs within the code for more info on that.

## Caveats

The registry is a singleton one, much like the way `ReactRenderer` is currently, but there are no technical challenges that prevent changing this in the future. See [limitations](./Limitations.md) for more info on this.