A list of different types of hook points in CodeIgniter:
post_controller_constructor - It is called immediately after your controller is started but before any method call.
pre_controller - It is called immediately before your controller being called. At this point, all the classes, security checks, and routing have been done.
post_sytem - It is called after the final page is sent to the browser at the end of the system execution.
pre_system - It is called much before the system execution. Only benchmark and hook class have been loaded at this point.
cache_override - It enables you to call your function in the output class.
display_override - It is used to send the final page at the end of file execution.
post_controller - It is called immediately after your controller is entirely executed.
