Алексей Яхненко

$string = "Текст1 | {Вложенный1 | Вложенный2 } | Текст2";
preg_match_all('/\s?([^|\{\}]+|\s?\{.+\}\s?)\s?/', $string, $matches);
var_dump($matches[1]);

array(3) {
  [0]=>
  string(12) "Текст1 "
  [1]=>
  string(45) "{Вложенный1 | Вложенный2 } "
  [2]=>
  string(11) "Текст2"
}

<ul>
<?php foreach ($nav_data as $item): ?>
  <li>
    <a href="<?php echo $item['href'] ?>">
      <?php echo $item["title"] ?>
    </a>
    <?php if (!empty($item['child'])): ?>
      <ul class="nav_submenu">
        <?php foreach ($item['child'] as $child): ?>
          <li class="nav_item">
            <a class="nav_link<?php echo $selected == $item['id'] ? ' active' : '' ?>" href="<?php echo $child['href'] ?>">
              <?php echo $child["title"] ?>
            </a>
          </li>
        <?php endforeach ?>
      </ul>
    <?php endif ?>
  </li>
<?php endforeach ?>
</ul>

function render($template, $variables) {
    extract($variables, EXTR_SKIP);
    ob_start();
    include $template;
    return ob_get_clean();
}

$calendar = array();
foreach ($events as $event) {
  $calendar[$event['date_start']] = isset($calendar[$event['date_start']]) ? 
    $calendar[$event['date_start']] + 1 : 
    1;
}

function formatSize($bytes)
    {
        if ($bytes < 1024)
        {
            return $bytes.' b';
        }
        elseif ($bytes < 1048576)
        {
            return round($bytes / 1024, 2).' kb';
        }
        elseif ($bytes < 1073741824)
        {
            return round($bytes / 1048576, 2).' mb';
        }
        elseif ($bytes < 1099511627776)
        {
            return round($bytes / 1073741824, 2).' gb';
        }
        elseif ($bytes < 1125899906842624)
        {
            return round($bytes / 1099511627776, 2).' tb';
        }
        elseif ($bytes < 1152921504606846976)
        {
            return round($bytes / 1125899906842624, 2).' pb';
        }
        else
        {
            return 'impossible huge!';
        }
    }

$cities = array(...);
$cities_with_letters = array();
foreach ($cities as $city) {
  $letter = substr($city['name'], 0, 1);
  $cities_with_letters[$letter][] = $city;
}

public function doSomething() {
  self::_doBeforeSomething();
  self::_doSomething();
  self::_doAfterSomething();
}