rails-presenter

Rails presenters using the SimpleDelegator pattern wrap models to provide view-specific formatting like HTML-safe badges and localized dates, keeping underlying models focused on data. This replaces ad-hoc helpers with clean, tested presentation objects.

Start the TDD workflow for Rails presenters by writing failing tests in test/presenters/, then implement presenter classes extending BasePresenter, and iterate until tests pass. This ensures view formatting logic like currency formatting and nil-safe helpers is validated before integration.

SimpleDelegator-based presenters wrap a model with a delegation layer so views call presentation methods while automatically forwarding unknown methods to the underlying model. This keeps model code data-focused and isolates display concerns like status badges and date formatting.

Rails presenters support nil-safe display helpers with fallback outputs and integrate I18n for localized formatting. They produce display-ready HTML-safe badges, formatted dates, and currency strings stored as cents, ensuring consistent UI rendering across resource pages.

Use Rails presenters instead of helpers when formatting logic becomes complex, requires testing, or wraps model-specific display concerns like Active/Inactive badges and euro amounts. Presenters extracted via SimpleDelegator provide a structured, testable alternative to scattered helper methods.

The Rails presenter pattern uses conventions including extending a BasePresenter class and incorporating ActionView helpers for view output. Presenters follow SimpleDelegator delegation to wrap models while providing tested, HTML-safe formatting methods for the view layer.