Routing
- Simple callback
- Dynamic argument include default value
- Option argument
- Controller
- Form
- Entity view
- Entity listing
- Entity form
- Injectable controller
- Dynamic route
- Alter dynamic route
Services
- Define custom service
- Alter service definitions
- Build complier pass
Plugins
- Define block plugin, output "Hello" in content
- What's the block use plugin api?
- Alter to change default output "Powered by Drupal" block.