When a view binding or tag renders a view, it first loads a controller. There are four callbacks around the rendering. The {action} is the same as the view file's name. So if you were rendering about.html, about would be the action. Simply create the correct method in the controller and it will called at the time.
| action name | description |
|---|---|
| before_action callbacks | All before actions are called before the main action method. If stop_chain is called, {action} will not be called and execution will be halted. |
{action} |
called before anything renders. Setup data you need |
| after_action callbacks | after_actions can not call stop_chain (in an after callback, it will raise an exception) |
{action}_ready |
called after the view renders. Run any code where you need to bind directly to the dom. jQuery setup code for example (bootstrap components) |
before_{action}_remove |
called before the view is removed (unrendered). Cleanup any dom bindings here. |
after_{action}_remove |
called after the view is removed from the dom. Cleanup anything in the controller that needs to be cleaned up. |
Most of the time all you will need is the action method to setup the controller, model, etc...