Views & Presenters

• Views render data. No calculations, queries, or complex conditionals.
• Use presenters to display logic. Instantiate in controller, use in view.
• Extract repeated markup into partials. Pass data via locals:, not instance variables.
• Helpers for simple formatting only (dates, currencies). If longer than 5 lines, use a presenter.
• Turbo: return status: :unprocessable_entity on failed forms. Keep Stimulus controllers small.