Encapsulating Views
summary
Rails views compile into methods on ActionView::Base so templates share instance variables and execute in a global scope, which makes unit testing and reasoning hard; GitHub builds ViewComponent to attach compiled templates to component objects, enabling per-component encapsulation, precompilation at boot to avoid per-process compile pauses, and fast unit tests (views compile into methods, components unit tests ~20ms vs controller ~1.5s). At scale—about 4,400 views and 3,000 partials—112 components cover ~550 usages and Rails 6.1 adds native support for third‑party component libraries.
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chapters (20)
- 0:00Start
- 3:45600 controllers
- 8:15Ecosystem Survey
- 8:53Draper & Cells
- 9:15Testing views
- 10:09View objects
- 12:09interface
- 17:46Views are methods
- 18:38Global scope
- 19:13Unit Testing
- 19:36Decorators, Presenters, Components
- 20:03one context for all views
- 26:10component gems
- 26:48Performance
- 28:59Levels of abstraction
- 29:473,000 partials
- 32:20Resiliency
- 32:35Exposing complexity
- 33:35Consistency
- 36:24Examples
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