ToStringTrait.php

<?php

namespace Drupal\Component\Utility;


/**
 * Wraps __toString in a trait to avoid some fatal errors.
 */
trait ToStringTrait {
    
    /**
     * Implements the magic __toString() method.
     */
    public function __toString() {
        try {
            return (string) $this->render();
        } catch (\Exception $e) {
            // User errors in __toString() methods are considered fatal in the Drupal
            // error handler.
            trigger_error(get_class($e) . ' thrown while calling __toString on a ' . static::class . ' object in ' . $e->getFile() . ' on line ' . $e->getLine() . ': ' . $e->getMessage(), E_USER_ERROR);
            // In case we are using another error handler that did not fatal on the
            // E_USER_ERROR, we terminate execution. However, for test purposes allow
            // a return value.
            return $this->_die();
        }
    }
    
    /**
     * For test purposes, wrap die() in an overridable method.
     */
    protected function _die() {
        die;
    }
    
    /**
     * Renders the object as a string.
     *
     * @return string|object
     *   The rendered string or an object implementing __toString().
     */
    public abstract function render();

}