title: PHP DomDocument class doesn't exist
body: <p>I was trying to use the class <code>DomDocument</code>in my php code on redhat linux server, but when I have tried the following code:</p>
  
  <pre><code>echo "class_exists(\"DomDocument\") = ".(class_exists("DomDocument")?" EXISTS ":" NOT EXISTS ")."&lt;br&gt;";
  </code></pre>
  
  <p>it prints:</p>
  
  <pre><code>class_exists("DomDocument") = NOT EXISTS 
  </code></pre>
  
  <p>after a small search I found that the extension <code>php-xml</code> should be installed, but the class still not exist, and the following is a snippet from <code>php -i</code> result:</p>
  
  <pre><code>dom
  
  DOM/XML =&gt; enabled
  DOM/XML API Version =&gt; 20031129
  libxml Version =&gt; 2.6.26
  HTML Support =&gt; enabled
  XPath Support =&gt; enabled
  XPointer Support =&gt; enabled
  Schema Support =&gt; enabled
  RelaxNG Support =&gt; enabled
  </code></pre>
  
  <p>What is still missing to make this <code>DomDocument</code> class work?</p>