The last little while have been all about URI’s for me. I’ve been engaged in discussions about the upcoming ‘PSR-7’, I started working on a sort of ‘hypermedia’-focussed router/repository type of system, and I recently ran into a bug in sabredav that forced me to get a better understanding of the URI specification, in particular on the topics of ‘normalization’ and resolving relative URLs.

All of this accumulated in a set of functions of operations I commonly need, which I’m now releasing as an open source library.

Yup! Yet another URI library. All this library is though, is a collection of 5 php functions:

• resolve to resolve relative uris.
• normalize to aid in comparing uris.
• parse, which mostly works like PHP’s parse_url.
• build to do the exact opposite of parse.
• split to easily get the ‘dirname’ and ‘basename’ of a URL without all the problems those two functions have.

The bug I ran into with sabredav, had to do with a client using a different encoding of a URI than I expected to. After diving into rfc3986, I realized that an application comparing uris cannot simply compare using strcmp or ===.

For example, the following uris are all identical:

• http://example.org/~foo/
• HTTP://example.ORG/~foo/
• http://example.org:80/~foo/
• http://example.org/%7Efoo/
• http://example.org/%7efoo/
• http://example.org/bar/./../~foo/

The new normalize function can take any of these previous URIs, and will turn it into the first.

<?php

use Sabre\Uri;

$input = 'HTTP://example.ORG:80/bar/./../%7efoo/';

echo Uri::normalize($input);
// output: http://example.org/~foo/

?>

I hope it’s useful for others.

Links:

• Packagist
• Full usage instructions
• GitHub