Arrays.php

<?php
	/**
	 * Returns array item or $default if item is not set.
	 * Example: $val = Arrays::get($arr, 'i', 123);
	 * @param  mixed  array
	 * @param  mixed  key
	 * @param  mixed  default value
	 * @return mixed
	 */
	public static function get(array $arr, $key, $default = NULL)
	{
		foreach (is_array($key) ? $key : array($key) as $k) {
			if (is_array($arr) && array_key_exists($k, $arr)) {
				$arr = $arr[$k];
			} elseif($arr instanceof Nette\ArrayHash && $arr->offsetExists($k)){
				$arr = $arr[$k];
			} else {
				if (func_num_args() < 3) {
					throw new Nette\InvalidArgumentException("Missing item '$k'.");
				}
				return $default;
			}
		}
		return $arr;
	}

Container.php

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