Observer pattern, Observer pattern class diagram

Observer pattern, Observer pattern class diagram

Observer Mode

<? Php // defines the observer call interface class transfer {protected $ _ observers = array (); // registers the public function register ($ sub) object) {$ this-> _ observers [] = $ sub;} // call public function trigger () {if (! Empty ($ this-> _ observers) {foreach ($ this-> _ observers as $ observer) {$ observer-> update ();}}}} // observer interface obserable {public function update () ;}// implements observer class listen implements obserable {public function update () {echo 'now first time you need to do listen <br/> ';} class read implements obserable {public function update () {echo 'now first time you need to read <br/> ';} class speak implements obserable {public function update () {echo 'now first time you need to speak <br/> ';} class write implements obserable {public function update () {echo 'now first time you need to write <br/> '; }}$ transfer = new transfer (); $ transfer-> register (new listen ()); $ transfer-> register (new read (); $ transfer-> register (new speak (); $ transfer-> register (new write ()); $ transfer-> trigger ();