view.feed.php overrides cause fatal error

[vdrover]

I want to customize Joomla's rss feed. I tried applying this using the MVC override plugin to override com_content/category/view.feed.php but when doing this, a fatal error occurs:

Fatal error: Class 'JFeedItem' not found in /home/milwaukeerugby/public_html/libraries/legacy/view/categoryfeed.php on line 103

[vdrover]

The problem is that view.feed.php and view.html.php have the same CLASS NAME so the override applies even when it should not.

The fix adds a check on the file name to make sure we're matching the current request format (i.e. html vs pdf vs feed).

<?php
/**
 * @package     RedCORE.Plugin
 * @subpackage  System.MVCOverride
 *
 * @copyright   Copyright (C) 2008 - 2015 redCOMPONENT.com. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE
 */

defined('_JEXEC') or die;

jimport('joomla.plugin.plugin');
jimport('joomla.filesystem.folder');

JLoader::import('system.mvcoverride.helper.override', JPATH_PLUGINS);
JLoader::import('system.mvcoverride.helper.codepool', JPATH_PLUGINS);
JLoader::import('system.mvcoverride.helper.mvcloader', JPATH_PLUGINS);

/**
 * PlgSystemMVCOverride class.
 *
 * @extends JPlugin
 * @since  2.5
 */
class PlgSystemMVCOverride extends JPlugin
{
    /**
     * Load the language file on instantiation.
     *
     * @var    boolean
     */
    protected $autoloadLanguage = true;

    protected static $componentList = array();

    protected static $option;

    /**
     * Constructor
     *
     * @param   object  &$subject  The object to observe
     * @param   array   $config    An optional associative array of configuration settings.
     *                             Recognized key values include 'name', 'group', 'params', 'language'
     *                             (this list is not meant to be comprehensive).
     */
    public function __construct(&$subject, $config = array())
    {
        JPlugin::loadLanguage('plg_system_mvcoverride');

        parent::__construct($subject, $config);

        JPluginHelper::importPlugin('redcore');

        $app = JFactory::getApplication();

        $includePath = $this->params->get('includePath', '{JPATH_BASE}/code,{JPATH_THEMES}/{template}/code');

        $includePath = str_replace(
            array('{JPATH_BASE}', '{JPATH_THEMES}', '{template}'),
            array(JPATH_BASE, JPATH_THEMES, $app->getTemplate()),
            $includePath
        );

        $includePath = explode(',', $includePath);

        // Register additional include paths for code replacements from plugins
        $app->triggerEvent('onMVCOverrideIncludePaths', array(&$includePath));

        MVCOverrideHelperCodepool::addCodePath($includePath);

        MVCLoader::setupOverrideLoader(
            $this->params->get('changePrivate', 0),
            $this->params->get('extendPrefix', ''),
            $this->params->get('extendSuffix', 'Default')
        );

        $this->setOverrideFiles();
    }

    /**
     * onAfterRoute function.
     *
     * @access public
     * @return void
     */
    public function onAfterRoute()
    {
        $option = $this->getOption();

        if ($option === false || !isset(self::$componentList[$option]))
        {
            return;
        }

        MVCOverrideHelperCodepool::initialize();

        // Add override paths for the current component files
        foreach (MVCOverrideHelperCodepool::addCodePath() as $codePool)
        {
            if (version_compare(JVERSION, '3.0', '>='))
            {
                JViewLegacy::addViewHelperPath($codePool . '/' . $option);
                JViewLegacy::addViewTemplatePath($codePool . '/' . $option);
            }
            else
            {
                JView::addViewHelperPath($codePool . '/' . $option);
                JView::addViewTemplatePath($codePool . '/' . $option);
            }

            JModuleHelper::addIncludePath($codePool . '/modules');
            JTable::addIncludePath($codePool . '/' . $option . '/tables');
            JModelForm::addComponentFormPath($codePool . '/' . $option . '/models/forms');
            JModelForm::addComponentFieldPath($codePool . '/' . $option . '/models/fields');
        }
    }

    /**
     * Set Override Files
     *
     * @return  void
     */
    public function setOverrideFiles()
    {
        $includePaths = MVCOverrideHelperCodepool::addCodePath(null);

        foreach ($includePaths as $includePath)
        {
            if ($components = JFolder::folders($includePath))
            {
                foreach ($components as $component)
                {
                    self::$componentList[$component] = $component;
                    $this->addOverrideFiles($includePath, $component);
                }
            }
        }
    }

    /**
     * Add new files
     *
     * @param   string  $includePath  Path for check inner files
     * @param   string  $component    Component name folder
     *
     * @return void
     */
    private function addOverrideFiles($includePath, $component)
    {
        $types = array('controllers', 'models', 'helpers', 'views');

        foreach ($types as $type)
        {
            $searchFolder = $includePath . '/' . $component . '/' . $type;

            if (!JFolder::exists($searchFolder))
            {
                continue;
            }

            $componentName = str_replace('com_', '', $component);

            switch ($type)
            {
                case 'helpers':
                if ($listFiles = JFolder::files($searchFolder, '.php', false, true))
                {
                    foreach ($listFiles as $file)
                    {
                        $fileName = JFile::stripExt(basename($file));
                        $indexName = $componentName . 'helper' . $fileName;
                        $this->getOverrideFileInfo($includePath, $component, $file, $type, $indexName);
                    }
                }
                    break;

                case 'views':
                // Reading view folders
                if ($views = JFolder::folders($searchFolder))
                {
                    foreach ($views as $view)
                    {
                        // Get view formats files
                        if ($listFiles = JFolder::files($searchFolder . '/' . $view, '.php', false, true))
                        {
                            foreach ($listFiles as $file)
                            {
                                if (!$this->isCurrentFormat(basename($file))) continue;
                                $this->getOverrideFileInfo($includePath, $component, $file, $type);
                            }
                        }
                    }
                }
                    break;

                default:
                if ($listFiles = JFolder::files($searchFolder, '.php', false, true))
                {
                    foreach ($listFiles as $file)
                    {
                        $this->getOverrideFileInfo($includePath, $component, $file, $type);
                    }
                }
            }
        }
    }

    /**
     * Get file info
     *
     * @param   string  $includePath  Path for check inner files
     * @param   string  $component    Component name folder
     * @param   string  $filePath     Checking file path
     * @param   string  $type         Type file
     * @param   string  $indexName    Name usage for helper index
     *
     * @return stdClass
     */
    private function getOverrideFileInfo($includePath, $component, $filePath, $type = '', $indexName = '')
    {
        $filePath = JPath::clean($filePath);
        $sameFolderPrefix = $component . '/' . $type;

        if ($type == 'helpers')
        {
            $app = JFactory::getApplication();
            $baseName = basename($filePath);
            $prefix = substr($baseName, 0, 5);

            if (($app->isAdmin() && $prefix == 'admin') || (!$app->isAdmin() && $prefix != 'admin') || !(!$app->isAdmin() && $prefix == 'admin'))
            {
                $realPath = JPATH_SITE . '/components' . substr($filePath, strlen($includePath));
            }
            else
            {
                $realPath = JPATH_ADMINISTRATOR . '/components/' . $sameFolderPrefix . '/' . substr($baseName, 5);
            }
        }
        else
        {
            $realPath = JPATH_BASE . '/components/' . substr($filePath, strlen($includePath));
        }

        $realPath = JPath::clean($realPath);

        if (!JFile::exists($realPath))
        {
            return;
        }

        $forOverrideFile = file_get_contents($realPath);
        $originalClass = MVCOverrideHelperOverride::getOriginalClass($forOverrideFile);
        unset($forOverrideFile);

        if ($type == 'helpers')
        {
            JLoader::register($indexName, $filePath);
        }
        else
        {
            // Set path for new file
            MVCLoader::setOverrideFile($originalClass, $filePath);
        }

        // Set path for override file
        MVCLoader::setOverrideFile(
            $originalClass,
            $realPath,
            true,
            $this->params->get('extendPrefix', ''),
            $this->params->get('extendSuffix', 'Default')
        );
    }

    /**
     * Get option
     *
     * @return bool|mixed|string
     */
    private function getOption()
    {
        if (self::$option)
        {
            return self::$option;
        }

        $app = JFactory::getApplication();
        self::$option = $app->input->getCmd('option', '');

        if (empty(self::$option) && $app->isSite())
        {
            $menuDefault = JFactory::getApplication()->getMenu()->getDefault();

            if (!$menuDefault)
            {
                return false;
            }

            $componentID = $menuDefault->component_id;
            $db = JFactory::getDBO();
            $query = $db->getQuery(true)
                ->select('element')
                ->from($db->qn('#__extensions'))
                ->where('extension_id = ' . $db->quote($componentID));
            $db->setQuery($query);
            self::$option = $db->loadResult();
        }

        return self::$option;
    }

    /**
     * Check if a view override file is relevant to the current format (i.e. html vs pdf vs feed)
     * 
     * @param   string  $viewFile   basename of the override file
     * @return  boolean
     */
    private function isCurrentFormat($viewFile)
    {
        $currentFormat = JFactory::getDocument()->getType();

        return ($viewFile == "view.$currentFormat.php");
    }
}