Method setupUninstall

/**
 * Method to do any prechecks and setup the uninstall job
 *
 * @return  void
 *
 * @since   4.0.0
 */
protected function setupUninstall()
{
    $manifestFile = JPATH_MANIFESTS . '/files/' . $this->extension->element . '.xml';
    // Because libraries may not have their own folders we cannot use the standard method of finding an installation manifest
    if (!file_exists($manifestFile)) {
        // Remove this row entry since its invalid
        $this->extension->delete($this->extension->extension_id);
        throw new \RuntimeException(Text::_('JLIB_INSTALLER_ERROR_FILE_UNINSTALL_INVALID_NOTFOUND_MANIFEST'));
    }
    // Set the files root path
    $this->parent->setPath('extension_root', JPATH_MANIFESTS . '/files/' . $this->extension->element);
    // Set the source path for compatibility with the API
    $this->parent->setPath('source', $this->parent->getPath('extension_root'));
    $xml = simplexml_load_file($manifestFile);
    // If we cannot load the XML file return null
    if (!$xml) {
        throw new \RuntimeException(Text::_('JLIB_INSTALLER_ERROR_FILE_UNINSTALL_LOAD_MANIFEST'));
    }
    // Check for a valid XML root tag.
    if ($xml->getName() !== 'extension') {
        throw new \RuntimeException(Text::_('JLIB_INSTALLER_ERROR_FILE_UNINSTALL_INVALID_MANIFEST'));
    }
    $this->setManifest($xml);
    // Attempt to load the language file; might have uninstall strings
    $this->loadLanguage(JPATH_MANIFESTS . '/files');
}