Smarty fetch causing 500 internal server error

[sufi]

Hello, I am trying to override smarty template from `ClientAreaPage` hook. But, when I fetch custom template, it keeps loading and loading until memory runs out, and gives a 500 internal server error! Can't seem to figure it out. Any help will be appreciable.

 

This is what I am doing:

add_hook('ClientAreaPage', 1, function( $vars ) {
    global $smarty;
    $version = $GLOBALS['CONFIG']['Version'];

    //tried with "post" and "output" filter - without any luck.
    $smarty->registerFilter('pre','template_override_output_filter');
});

function template_override_output_filter($tpl_output, Smarty_Internal_Template $template) {
    global $smarty;

    $template_file_path = $template->_current_file;
    
    //getting filename
    $parts = explode('/', $template_file_path);
    $template_file_name = array_pop($parts);

    $custom_directory = 'custom';
    $new_file = ROOTDIR . DIRECTORY_SEPARATOR . 'templates' . DIRECTORY_SEPARATOR . $custom_directory . DIRECTORY_SEPARATOR . $template_file_name;

    if (!file_exists($new_file)) {
        return $tpl_output;
    }
    
    $tpl_output = $smarty->fetch($new_file);
    
    return $tpl_output;
}