SimpleXML: Add namespace example

Author: vrana

reference/simplexml/examples.xml

@@ -412,6 +412,49 @@ blah
     </screen>
    </example>
   </para>
+  <para>
+   <example>
+    <title>Working with namespaces</title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+$data = <<<XML
+<movies xmlns="http://default" xmlns:a="http://a">
+ <movie xml:id="movie1" a:link="IMDB">
+  <a:actor>Onlivia Actora</a:actor>
+ </movie>
+</movies>
+XML;
+
+$movies = simplexml_load_string($data);
+
+// Namespace http://www.w3.org/XML/1998/namespace is available as "xml".
+echo $movies->movie->attributes("xml", true)["id"] . "\n";
+
+// Namespaced attributes can be accessed with attributes().
+echo $movies->movie->attributes("a", true)["link"] . "\n";
+
+// Using namespace URI allows document to use any namespace alias.
+echo $movies->movie->attributes("http://a")["link"] . "\n";
+
+// Children can be accessed with children().
+echo $movies->movie->children("http://a")->actor . "\n";
+
+// Using xpath() with namespace requires registering it first.
+$movies->registerXPathNamespace("a", "http://a");
+echo count($movies->xpath("//a:actor")) . "\n";
+
+// Even the default namespace must be registered.
+$movies->registerXPathNamespace("default", "http://default");
+echo count($movies->xpath("//default:movie")) . "\n";
+
+// This is empty.
+echo count($movies->xpath("//movie")) . "\n";
+?>
+]]>
+    </programlisting>
+   </example>
+  </para>
  </section>
 
  <section xml:id="simplexml.examples-errors">