the REAL factory method pattern

FactoryMethod/Bicycle.php

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+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\FactoryMethod;
+
+/**
+ * Bicycle is a bicycle
+ */
+class Bicycle implements Vehicle
+{
+
+    public function setColor($rgb)
+    {
+        
+    }
+
+}

FactoryMethod/FactoryMethod.php

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+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\FactoryMethod;
+
+/**
+ * FactoryMethod is a factory method. The good point on the SimpleFactory
+ * is you can subclass it to implement different way to create vehicle for
+ * each country.
+ * 
+ * For simple case, this abstracct class could be just an interface
+ */
+abstract class FactoryMethod
+{
+
+    /**
+     * The children of the class must implement this method
+     * 
+     * Sometimes this method can be public to get "raw" object
+     * 
+     * @param string $type a generic type
+     * 
+     * @return Vehicle a new vehicle
+     */
+    abstract protected function createVehicle($type);
+
+    /**
+     * Creates a new vehicle
+     * 
+     * @param string $type
+     * 
+     * @return Vehicle a new vehicle
+     */
+    public function create($type)
+    {
+        $obj = $this->createVehicle($type);
+        $obj->setColor("#f00");
+
+        return $obj;
+    }
+
+}

FactoryMethod/Ferrari.php

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+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\FactoryMethod;
+
+/**
+ * Ferrari is a italian car
+ */
+class Ferrari implements Vehicle
+{
+
+    public function setColor($rgb)
+    {
+        
+    }
+
+}

FactoryMethod/GermanFactory.php

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+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\FactoryMethod;
+
+/**
+ * GermanFactory is vehicle factory in Germany
+ */
+class GermanFactory extends FactoryMethod
+{
+
+    /**
+     * @inheritdoc
+     */
+    protected function createVehicle($type)
+    {
+        switch ($type) {
+            case 'cheap' :
+                return new Bicycle();
+                break;
+            case 'fast' :
+                return new Porsche();
+                break;
+            default :
+                throw new \InvalidArgumentException("$type is not a valid vehicle");
+        }
+    }
+
+}

FactoryMethod/ItalianFactory.php

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+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\FactoryMethod;
+
+/**
+ * ItalianFactory is vehicle factory in Italy
+ */
+class ItalianFactory extends FactoryMethod
+{
+
+    /**
+     * @inheritdoc
+     */
+    protected function createVehicle($type)
+    {
+        switch ($type) {
+            case 'cheap' :
+                return new Bicycle();
+                break;
+            case 'fast' :
+                return new Ferrari();
+                break;
+            default :
+                throw new \InvalidArgumentException("$type is not a valid vehicle");
+        }
+    }
+
+}

FactoryMethod/Porsche.php

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+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\FactoryMethod;
+
+/**
+ * Porsche is a german car
+ */
+class Porsche implements Vehicle
+{
+
+    public function setColor($rgb)
+    {
+        
+    }
+
+}

FactoryMethod/Vehicle.php

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+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\FactoryMethod;
+
+/**
+ * Vehicle is a contract for a vehicle
+ */
+interface Vehicle
+{
+
+    function setColor($rgb);
+}

Tests/FactoryMethod/FactoryMethodTest.php

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+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\Tests\FactoryMethod;
+
+use DesignPatterns\FactoryMethod;
+
+/**
+ * FactoryMethodTest tests the factory method pattern
+ */
+class FactoryMethodTest extends \PHPUnit_Framework_TestCase
+{
+
+    protected $type = array('cheap', 'fast');
+
+    public function getShop()
+    {
+        return array(
+            array(new FactoryMethod\GermanFactory()),
+            array(new FactoryMethod\ItalianFactory())
+        );
+    }
+
+    /**
+     * @dataProvider getShop
+     */
+    public function testCreation(FactoryMethod\FactoryMethod $shop)
+    {
+        // this test method acts as a client for the factory. We don't care
+        // about the factory, all we know is it can produce vehicle
+        foreach ($this->type as $oneType) {
+            $vehicle = $shop->create($oneType);
+            $this->assertInstanceOf('DesignPatterns\FactoryMethod\Vehicle', $vehicle);
+        }
+    }
+
+    /**
+     * @dataProvider getShop
+     * @expectedException \InvalidArgumentException
+     * @expectedExceptionMessage spaceship is not a valid vehicle
+     */
+    public function testUnknownType(FactoryMethod\FactoryMethod $shop)
+    {
+        $shop->create('spaceship');
+    }
+
+}