Pico::sortPages PHP Method

    protected function sortPages()
    {
        // sort pages
        $order = $this->getConfig('pages_order');
        $alphaSortClosure = function ($a, $b) use($order) {
            $aSortKey = basename($a['id']) === 'index' ? dirname($a['id']) : $a['id'];
            $bSortKey = basename($b['id']) === 'index' ? dirname($b['id']) : $b['id'];
            $cmp = strcmp($aSortKey, $bSortKey);
            return $cmp * ($order === 'desc' ? -1 : 1);
        };
        if ($this->getConfig('pages_order_by') === 'date') {
            // sort by date
            uasort($this->pages, function ($a, $b) use($alphaSortClosure, $order) {
                if (empty($a['time']) || empty($b['time'])) {
                    $cmp = empty($a['time']) - empty($b['time']);
                } else {
                    $cmp = $b['time'] - $a['time'];
                }
                if ($cmp === 0) {
                    // never assume equality; fallback to alphabetical order
                    return $alphaSortClosure($a, $b);
                }
                return $cmp * ($order === 'desc' ? 1 : -1);
            });
        } else {
            // sort alphabetically
            uasort($this->pages, $alphaSortClosure);
        }
    }