Index: oop5.xml
===================================================================
RCS file: /repository/phpdoc/en/language/oop5.xml,v
retrieving revision 1.13
diff -u -p -r1.13 oop5.xml
--- oop5.xml	20 Jun 2007 22:24:12 -0000	1.13
+++ oop5.xml	21 Oct 2007 00:47:30 -0000
@@ -30,6 +30,7 @@
   &language.oop5.object-comparison;
   &language.oop5.reflection;
   &language.oop5.typehinting;
+  &language.oop5.late-static-bindings;
 </chapter>
  
 <!-- Keep this comment at the end of the file
Index: oop5/late-static-bindings.xml
===================================================================
RCS file: oop5/late-static-bindings.xml
diff -N oop5/late-static-bindings.xml
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ oop5/late-static-bindings.xml	21 Oct 2007 00:47:30 -0000
@@ -0,0 +1,260 @@
+<?xml version="1.0" encoding="iso-8859-1"?>
+<!-- $Revision:$ -->
+ <sect1 xml:id="language.oop5.late-static-bindings" xmlns="http://docbook.org/ns/docbook">
+  <title>Late Static Bindings</title>
+  <para>
+   As of PHP 5.3.0, PHP implements a feature called late static bindings which
+   can be used to reference the called class in a context of static inheritance.
+  </para>
+
+  <para>
+   This feature was named "late static bindings" with an internal perspective in
+   mind. "Late binding" comes from the fact that <literal>static::</literal> 
+   will no longer be resolved using the class where the method is defined but 
+   it will rather be computed using runtime information.
+
+   It was also called a "static binding" as it can be used for (but is not 
+   limited to) static method calls.
+  </para>
+
+  <sect2 xml:id="language.oop5.late-static-bindings.self">
+   <title>Limitations of <literal>self::</literal></title>
+   <para>
+    Static references to the current class like <literal>self::</literal> or 
+    <literal>__CLASS__</literal> are resolved using the class in which the 
+    function belongs, as in where it was defined:
+   </para>
+   <example>
+    <title><literal>self::</literal> usage</title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+class A {
+    public static function who() {
+        echo __CLASS__;
+    }
+    public static function test() {
+        self::who();      
+    }  
+}  
+
+class B extends A {      
+    public static function who() {
+         echo __CLASS__;
+    }  
+}   
+
+B::test();
+?>  
+]]>
+    </programlisting>
+    &example.outputs;
+    <screen>
+<![CDATA[
+A
+]]>
+    </screen>
+   </example>
+
+  </sect2>
+ 
+  <sect2 xml:id="language.oop5.late-static-bindings.usage">
+   <title>Late Static Bindings' usage</title>
+
+   <para>
+    Late static bindings tries to solve that limitation by introducing a 
+    keyword that references the class that was initially called at runtime.
+    Basically, a keyword that would allow you to reference 
+    <literal>B</literal> from <literal>test()</literal> in the previous 
+    example. It was decided not to introduce a new keyword but rather use 
+    <literal>static</literal> that was already reserved.
+   </para>
+
+   <example>
+    <title><literal>static::</literal> simple usage</title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+class A {
+    public static function who() {
+        echo __CLASS__;
+    }
+    public static function test() {
+        static::who(); // Here comes Late Static Bindings     
+    }  
+}  
+
+class B extends A {      
+    public static function who() {
+         echo __CLASS__;
+    }  
+}   
+
+B::test();
+?>  
+]]>
+    </programlisting>
+    &example.outputs;
+    <screen>
+<![CDATA[
+B
+]]>
+    </screen>
+   </example>
+   <note>
+    <para>
+     <literal>static::</literal> does not work like <literal>$this</literal> for
+     static methods! <literal>$this-></literal> follows the rules of 
+     inheritance while <literal>static::</literal> doesn't. This difference is
+     detailed later on this manual page.
+    </para>
+   </note>
+   <example>
+    <title><literal>static::</literal> usage in a non-static context</title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+class TestChild extends TestParent {
+    public function __construct() {
+        static::who();
+    }
+
+    public function test() {
+        $o = new TestParent();
+    }
+
+    public static function who() {
+        echo __CLASS__."\n";
+    }
+}
+
+class TestParent {
+    public function __construct() {
+        static::who();
+    }
+
+    public static function who() {
+        echo __CLASS__."\n";
+    }
+}
+$o = new TestChild;
+$o->test();
+
+?>  
+]]>
+    </programlisting>
+    &example.outputs;
+    <screen>
+<![CDATA[
+TestChild
+TestParent
+]]>
+    </screen>
+   </example>
+   <note>
+    <para>
+     Late static bindings' reslution will stop at a fully resolved static call with no fallback.
+    </para>
+    <example>
+     <title>Fully resolved static calls</title>
+     <programlisting role="php">
+<![CDATA[
+<?php
+class A {
+    public static function foo() {
+        static::who();
+    }
+        
+    public static function who() {
+        echo __CLASS__."\n";
+    }
+}
+
+class B extends A {
+    public static function test() {
+        A::foo();
+    }
+
+    public static function who() {
+        echo __CLASS__."\n";
+    }
+}
+
+B::test();
+?>  
+]]>
+     </programlisting>
+     &example.outputs;
+     <screen>
+<![CDATA[
+A
+]]>
+     </screen>
+    </example>
+   </note>
+  </sect2>
+  <sect2 xml:id="language.oop5.late-static-bindings.edge-cases">
+   <title>Edge cases</title>
+   <para>
+    There are lots of different ways to trigger a method call in PHP, like 
+    callbacks or magic methods. As late static bindings base their resolution
+    on runtime information, it might give unexpected results in so-called edge 
+    cases. 
+   </para>
+   <example>
+    <title>Late static bindings inside magic methods</title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+class A {
+
+   protected static function who() {
+        echo __CLASS__."\n";
+   }
+
+   public function __get($var) {
+       return static::who();
+   }
+}
+
+class B extends A {
+
+   protected static function who() {
+        echo __CLASS__."\n";
+   }
+}
+
+$b = new B;
+$b->foo;
+?>  
+]]>
+    </programlisting>
+    &example.outputs;
+    <screen>
+<![CDATA[
+B
+]]>
+    </screen>
+   </example>
+  </sect2>
+ </sect1>
+<!-- Keep this comment at the end of the file
+Local variables:
+mode: sgml
+sgml-omittag:t
+sgml-shorttag:t
+sgml-minimize-attributes:nil
+sgml-always-quote-attributes:t
+sgml-indent-step:1
+sgml-indent-data:t
+indent-tabs-mode:nil
+sgml-parent-document:nil
+sgml-default-dtd-file:"../../manual.ced"
+sgml-exposed-tags:nil
+sgml-local-catalogs:nil
+sgml-local-ecat-files:nil
+End:
+vim600: syn=xml fen fdm=syntax fdl=2 si
+vim: et tw=78 syn=sgml
+vi: ts=1 sw=1
+-->