simple RoR style uri mapping snippet

uri_mapping.php

<?php

$str = "/parent/:dbname/:collname/:id";

function uri2regex ($str, &$params_keys) {
    $word = "([0-9a-zA-Z_-]+)";
    $flag = preg_match_all("/:\w+/",$str, $matches);
    $params = $matches[0];
    array_walk($params, 'uriNormalize');
    $ret = preg_replace("/:\w+/", $word, $str);
    $ret = str_replace("/", "\/", $ret);
    $params_keys = $params;
    return "/^" . $ret . "/";
}

function uriNormalize (&$item) {
    $item = str_replace(":", "", $item);
}


$pkeys = array();
$regex = uri2regex($str, $pkeys);

var_dump($regex);

$uri = "/parent/foo_db/bar_coll/200";

$flag = preg_match_all($regex, $uri, $matches);

$route = array();

array_shift($matches);

foreach ($pkeys as $key) {
    $match = array_shift($matches);
    $route[$key] = array_shift($match);
}

var_dump($route);

/*
output:

string(65) "/^\/parent\/([0-9a-zA-Z_-]+)\/([0-9a-zA-Z_-]+)\/([0-9a-zA-Z_-]+)/"
array(3) {
  ["dbname"]=>
  string(6) "foo_db"
  ["collname"]=>
  string(8) "bar_coll"
  ["id"]=>
  string(3) "200"
}

*/