Why does CKEditor5 use a promise to initialize it?

Question

Example:

ClassicEditor
.create( document.querySelector( '#editor' ) )
.then( editor => {
    console.log( editor );
} )
.catch( error => {
    console.error( error );
} );

Why would editor creation need to be asynchronous?

Answer 1

The editor initialization can be asynchronous because some editor features or editor UI may require asynchronous initialisation.

I'm inconcrete on purpose here. As a framework developer, I don't know what kind of features the users of the framework will want to implement. However, I know some examples from the past:

• an <iframe>-based editor (iframes are initialized asynchronously), i.e. an editor in which the content is edited within an <iframe>,
• real-time collaboration features which need to retrieve the content from the server.

If you're implementing a plugin which need to defer initialisation, then you can simply return a promise from its init() or afterInit() methods:

class MyPlugin extends Plugin {
    init() {
        return new Promise( resolve => {
            // Call resolve() once your plugin is ready:
            resolve();
        } );
    }
}