TODO.md

• we may want to prevent race condition in multiple build calls.

• font image sprite url issue

• now update before initialized, which seems awkward.

  • since we have passed value after init, perhaps the init update is totally unnecessary?

• stringify / parse

  • widget may return object.
  • we may need methods in the returned object.
  • however, object may be stored as plain JSON.
  • we don't have these methods when object are loaded from plain JSON.
  • we will have to reinit them manually.
  • this creates a dependency from widget users to the widget.
  • thus, alternatively we should standardize the returned value, which shall be plain JSON.
  • users are responsible for use these values to init any object, depending on any libs.