parse SEF links function

[bkeep]

This is a small function to take a relative link and return it as a search engine friendly link.

listings.php?action=view&id=5&sort=asc turns into this -> listings/action/view/id/5/sort/asc/

function parse_sef_links($link)
{
	$use_fancy_urls = true;

if (isset($link)) {
	$this_url = str_replace('&', '&', $link);
	$this_url = str_replace('&', '&', $this_url);
	if (preg_match('!^[\w -]+(\.[^?]+)$!', $this_url)) {
		return $this_url;
	} else {
		$this_url_array = explode('?', $this_url);
	}

	$query_string_array = explode('&', $this_url_array[1]);
	list($url_base,$ext) = split('\.',$this_url_array[0],2);
	if ($use_fancy_urls) {
		foreach ($query_string_array as $keys => $values) {
			$values = explode('=', $values);
			$this_query_string .= "$values[0]/$values[1]/";
		}

		$_ret = "$url_base/$this_query_string";
		//returns output -> listings/action/view/id/5/sort/asc/
		return $_ret;
	} else {
		//returns output -> listings.php?action=view&id=5&sort=asc
		$_ret = "$this_url";
		return $_ret;
	        }
}
return false;
}

print parse_sef_links("listings.php?action=view&id=5&sort=asc");

Thanks for taking the time to look this over and give feedback
Brandon

[Weedpacket]

$link is always going to be set, so the isset($link) is redundant. Perhaps you mean !empty($link)?

You don't initialise $this_query_string before you start appending to it.

Why do you use split('.') when you could use explode('.')?

You might be able to shorten some of the parsing with parse_url() and parse_str() functions.

[bkeep]

"$link is always going to be set, so the isset($link) is redundant. Perhaps you mean !empty($link)?"

Yup I didn't use the entire function and when I copy pasted it from my editor I changed that for some reason but it is not in the original code. You are exactly right.

"You don't initialize $this_query_string before you start appending to it."
oops I fixed that.

"Why do you use split('.') when you could use explode('.')?"
I never really thought there was a difference until your question so I did a little research and came up some useful info on the difference of split vs explode vs preg_split.

Just goes to show you that doing things the same way just for the sake of doing them the same way isn't always the best way. I had several other functions that I used split to break apart urls and just used it to do the same thing I had always done.
What I didn't know beforehand was split uses regular expressions to match and is slower than preg_split or explode.

"You might be able to shorten some of the parsing with parse_url() and parse_str() functions."

I had looked at the parse_url() function and found a note on relative URLs

Note: This function doesn't work with relative URLs

I had not looked into the parse_str() function but will do so.

Thanks for taking your time to look at my code, your critique has been valuable to me.
Best Regards,
Brandon