Container.php

<?php

	/**
	 * Expands %placeholders% in string. Return mixed when expanding pure ^%item%$.
	 * @param  string
	 * @return mixed
	 * @throws Nette\InvalidStateException
	 */
	public function expand($s)
	{
		if (is_string($s) && strpos($s, '%') !== FALSE) {
			$pattern = '%([a-z0-9._-]*)%';
			$single = FALSE;
			$that = $this;
			$replacer = function ($m) use ($that, $single) { // intentionally @ due PHP bug #39257
				list(, $param) = $m;
				if ($param === '') {
					return '%';
				} elseif (!is_scalar($val = Nette\Utils\Arrays::get((array) $that->params, explode('.', $param))) && $singel !== TRUE) {
					throw new Nette\InvalidStateException("Parameter '$param' is not scalar.");
				}
				return $val;
			};
			if ($m = Nette\Utils\Strings::match($s, '#^$pattern$#i')) {
				$single = TRUE;
				return $replacer($m);
			} else {
				return @preg_replace_callback('#$pattern#i', $replacer, $s);
			}
		}
		return $s;
	}