Source for file ExtensionRequirement.class.php

<?php
/**
 * @package polyphony.startupcheck
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: ExtensionRequirement.class.php,v 1.6 2007/09/19 14:04:50 adamfranco Exp $
 */
 
/**
 * This {@link StartupRequirement} checks to make sure PHP has a given extension loaded (or can load it).
 *
 * @package polyphony.startupcheck
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: ExtensionRequirement.class.php,v 1.6 2007/09/19 14:04:50 adamfranco Exp $
 */
class ExtensionRequirement extends StartupRequirement {
 
    var $_extension;
    
    /**
     * Constructor
     * @param string $extension The name of the extension that must be loaded (case-sensitive)
     */
    function ExtensionRequirement($extension) {
        $this->_extension = $extension;
    }
    
    /**
     * Checks the environment and returns a status value. Return value is one of STARTUP_STATUS_* defines.
     * @access public
     * @return integer 
     */
    function getStatus()
    {
        debug::output(
            "ExtensionRequirement - checking to make sure PHP loaded $this->_extension.", 7, "StartupCheck");
        if (!extension_loaded($this->_extension)) {
            $prefix = (PHP_SHLIB_SUFFIX == 'dll') ? 'php_' : '';
            if (!@dl($prefix . $this->_extension . "." . PHP_SHLIB_SUFFIX)) {
                StartupCheck::error(dgettext("polyphony",
                            sprintf(
                                "ExtensionRequirement - PHP extension <b>%s</b> is neither loaded nor could we load it dynamically.",
                                $this->_extension
                            )));
                return STARTUP_STATUS_ERROR;
            }
        }
        return STARTUP_STATUS_OK;
    }
    
    /**
     * Returns this requirement's display name.
     * @access public
     * @return string 
     */
    function getDisplayName()
    {
        return dgettext("polyphony","PHP Extension Check")." : ".$this->_extension;
    }
    
    /**
     * Returns a {@link Wizard} object containing fields for user input to complete installation process.
     * @access public
     * @return ref object
     */
    function createWizard()
    {
        $null = null; 
        return $null;
    }
    
    /**
     * Tells the requirement class to perform its update/install operation. If user input is required, it is passed in the form of a {@link WizardStep} containing field values.
     * @param optional array $properties An array of {@link WizardProperty} objects corresponding to the {@link Wizard} as created by {@link createWizard()}.
     * @access public
     * @return int Returns the new status of this requirement after attempting update.
     */
    function doUpdate( $properties = null )
    {
        return STARTUP_STATUS_NOT_CHECKED;
    }
}