From 1569db132891b8423486820535ccfcdd833f36ff Mon Sep 17 00:00:00 2001
From: Trismegiste <florent.g@allopneus.com>
Date: Sun, 12 May 2013 11:13:14 +0200
Subject: [PATCH 1/3] add a template method

---
 TemplateMethod/Journey.php | 76 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 TemplateMethod/Journey.php

diff --git a/TemplateMethod/Journey.php b/TemplateMethod/Journey.php
new file mode 100644
index 0000000..ce93b82
--- /dev/null
+++ b/TemplateMethod/Journey.php
@@ -0,0 +1,76 @@
+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\TemplateMethod;
+
+/**
+ * Template Method is a behavioral design pattern.
+ * 
+ * Perhaps you have encoutered it many times already. The idea is to let subclasses
+ * of this abstract template "finish" the behavior of an algorithm.
+ * 
+ * A.k.a the "Hollywood principle" : "" Don't call us, we call you. ""
+ * This class is not called by subclasses but the inverse.
+ * How ? With abstraction of course. 
+ * 
+ * In other words, this is a skeleton of algorithm, well-suited for framework 
+ * libraries. The user has just to implement one method and the superclass do
+ * the job.
+ * 
+ * It is an easy way to decouple concrete classes and reduce copy-paste, 
+ * that's why you'll find it everywhere.
+ */
+abstract class Journey
+{
+
+    /**
+     * This is the public service provided by this class and its subclasses.
+     * Notice it is final to "freeze" the global behavior of algorithm.
+     * If you want to override this contract, make an interface with only takeATrip() 
+     * and subclass it.
+     */
+    public final function takeATrip()
+    {
+        $this->buyAFlight();
+        $this->takePlane();
+        $this->enjoyVacation();
+        $this->buyGift();
+        $this->takePlane();
+    }
+
+    /**
+     * This method must be implemented, this is the key-feature of this pattern
+     */
+    abstract protected function enjoyVacation();
+
+    /**
+     * This method is also part of the algorithm but it is optional.
+     * This is an "adapter" (do not confuse with the Adapter pattern, not related)
+     * You can override it only if you need to.
+     */
+    protected function buyGift()
+    {
+        
+    }
+
+    // this method will be unknown by subclasses (better)    
+    private function buyAFlight()
+    {
+        echo "Buying a flight\n";
+    }
+
+    // sbclasses will get access to this method but cannot override it and 
+    // compromise this algorithm (warning : cause of cyclic depedencies)
+    final protected function takePlane()
+    {
+        echo "Taking the plane\n";
+    }
+
+    // A note regarding the keyword "final" : don't use it when you start coding :
+    // add it after you narrow and know exacly what change and what remain unchanged
+    // in this algorithm. 
+    // [abstract] x [3 access] x [final] = 12 combinations, it can be hard !
+}
\ No newline at end of file

From 1ab184fca76ec476a01f71d879df426a54b96b1e Mon Sep 17 00:00:00 2001
From: Trismegiste <florent.g@allopneus.com>
Date: Sun, 12 May 2013 11:13:37 +0200
Subject: [PATCH 2/3] make concrete journey

---
 TemplateMethod/BeachJourney.php | 20 ++++++++++++++++++++
 TemplateMethod/CityJouney.php   | 20 ++++++++++++++++++++
 2 files changed, 40 insertions(+)
 create mode 100644 TemplateMethod/BeachJourney.php
 create mode 100644 TemplateMethod/CityJouney.php

diff --git a/TemplateMethod/BeachJourney.php b/TemplateMethod/BeachJourney.php
new file mode 100644
index 0000000..cec7bab
--- /dev/null
+++ b/TemplateMethod/BeachJourney.php
@@ -0,0 +1,20 @@
+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\TemplateMethod;
+
+/**
+ * BeachJourney is vacation at the beach
+ */
+class BeachJourney extends Journey
+{
+
+    protected function enjoyVacation()
+    {
+        echo "Swimming and sun-bathing\n";
+    }
+
+}
\ No newline at end of file
diff --git a/TemplateMethod/CityJouney.php b/TemplateMethod/CityJouney.php
new file mode 100644
index 0000000..30e834a
--- /dev/null
+++ b/TemplateMethod/CityJouney.php
@@ -0,0 +1,20 @@
+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\TemplateMethod;
+
+/**
+ * CityJouney is a journey in a city
+ */
+class CityJouney extends Journey
+{
+
+    protected function enjoyVacation()
+    {
+        echo "Eat, drink, take photos and sleep\n";
+    }
+
+}
\ No newline at end of file

From 8eb06265300e671476364cb53b258388d83433e3 Mon Sep 17 00:00:00 2001
From: Trismegiste <florent.g@allopneus.com>
Date: Sun, 12 May 2013 11:13:56 +0200
Subject: [PATCH 3/3] add tests for this pattern

---
 Tests/TemplateMethod/JourneyTest.php | 49 ++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Tests/TemplateMethod/JourneyTest.php

diff --git a/Tests/TemplateMethod/JourneyTest.php b/Tests/TemplateMethod/JourneyTest.php
new file mode 100644
index 0000000..fcfc4e6
--- /dev/null
+++ b/Tests/TemplateMethod/JourneyTest.php
@@ -0,0 +1,49 @@
+<?php
+
+/*
+ * DesignPatternPHP
+ */
+
+namespace DesignPatterns\Tests\TemplateMethod;
+
+use DesignPatterns\TemplateMethod;
+
+/**
+ * JourneyTest tests all journeys
+ */
+class JourneyTest extends \PHPUnit_Framework_TestCase
+{
+
+    public function testBeach()
+    {
+        $journey = new TemplateMethod\BeachJourney();
+        $this->expectOutputRegex('#sun-bathing#');
+        $journey->takeATrip();
+    }
+
+    public function testCity()
+    {
+        $journey = new TemplateMethod\CityJouney();
+        $this->expectOutputRegex('#drink#');
+        $journey->takeATrip();
+    }
+
+    /**
+     * How to test an abstract template method with PHPUnit
+     */
+    public function testLasVegas()
+    {
+        $journey = $this->getMockForAbstractClass('DesignPatterns\TemplateMethod\Journey');
+        $journey->expects($this->once())
+                ->method('enjoyVacation')
+                ->will($this->returnCallback(array($this, 'mockUpVacation')));
+        $this->expectOutputRegex('#Las Vegas#');
+        $journey->takeATrip();
+    }
+
+    public function mockUpVacation()
+    {
+        echo "Fear and loathing in Las Vegas\n";
+    }
+
+}
\ No newline at end of file