traits.php

<?php
// Example 1: -----------------------------------------------------------------
// source:
// https://leanpub.com/the-essentials-of-object-oriented-php
// Context:
// a `Price` trait has a method `changePriceByDollars()` that // calculates the new price 
// from the old price and the price change in dollars. and another trait for special prices 
// with a method that announce that the model is on special sell:

// Define traits
trait Price {
  public function changePriceByDollars($price, $change)
    {
    return $price + $change;
    }
}
trait SpecialSell {
  public function annonunceSpecialSell() {
    return __CLASS__ . " on special sell";
  }
}
// Import/use them in classes:
class Bwm {
  use Price;
  use SpecialSell;
}
class Mercedes {
  use Price;
  use SpecialSell;
}
// Use them:
$mercedes1 = new Mercedes();
echo $mercedes1->changePriceByDollars(42000, -2100);
echo $mercedes1->annonunceSpecialSell();

// Example 2: -----------------------------------------------------------------
// source:
// https://www.php.net/manual/en/language.oop5.traits.php
// Context:
// Hello world

trait HelloWorld {
    public function sayHello() {
        echo 'Hello World!';
    }
}

class TheWorldIsNotEnough {
    use HelloWorld;
    public function sayHello() {
        echo 'Hello Universe!';
    }
}

(new TheWorldIsNotEnough)->sayHello();

// Example 3: -----------------------------------------------------------------
// source:
// https://www.php.net/manual/en/language.oop5.traits.php
// Context:
// Logger for new account and new user

trait Logger {
  function log($msg) {
    echo date('Y-m-d h:i:s') . ':' . '(' . __CLASS__ .  ') ' . $msg . PHP_EOL;
  }
}

class BankAccount{
  use Logger;
  private $accountNumber;

  function __construct($accountNumber){
    $this->accountNumber = $accountNumber;
    $this->log("A new $accountNumber bank account created");
  }
}

class User{
  use Logger;
  function __construct() {
    $this->log("A new user created");
  }
}


(new BankAccount('1234567674'));

(new User());

// Example 4: -----------------------------------------------------------------
// source:
// https://www.php.net/manual/en/language.oop5.traits.php
// Context:
// Controllers and CRUD

class Controller {
  /* Controller-specific methods defined here. */
}

class AdminController extends Controller {
  /* Controller-specific methods inherited from Controller. */
  /* Admin-specific methods defined here. */
}

trait CrudControllerTrait {
  /* CRUD-specific methods defined here. */
}

class AdminCrudController extends AdminController {
  use CrudControllerTrait;
  /* Controller-specific methods inherited from Controller. */
  /* Admin-specific methods inherited from AdminController. */
  /* CRUD-specific methods defined by CrudControllerTrait. */
}