Is there a better way to do this regex? - regex

Question

I finally figured out a good/easy way to make clean URLs with regex on my site in this format below, however it will require a very large .htaccess file, I know from the post on here that it is supposed to not be to bad on performance to use mod_rewrite but I have never really seen it used where the way I am, with a seperate entry for almost every page of my site.
Below is an example of an entry, there is 2 entries for 1 page, the first entry re-writes
http://www.example.com/users/online/friends/
to
http://www.example.com/index.php?p=users.online.friends
It works great but if the user is not on the first page then there is another thing added to the URL for paging and I had to write another entry to rewrite when this happens, is this the correct way or should these be combined somehow?
RewriteRule ^users/online/friends/*$ ./index.php?p=users.online.friends&s=8
RewriteRule ^users/online/friends/(\d+)/*$ ./index.php?p=users.online.friends&s=8&page=$1
The second one would do this
http://www.example.com/users/online/friends/22/
to
http://www.example.com/index.php?p=users.online.friends&page=22

Answer 1

It depends what you think is more readable, but here's how you could do it with a single rule:
RewriteRule ^users/online/friends(/(\d+))?/*$ ./index.php?p=users.online.friends&s=8&page=$2
(Edited to be more faithful to treatment of trailing slash in original question. Was: RewriteRule ^users/online/friends/((\d+)/*)?$ ./index.php?p=users.online.friends&s=8&page=$2)
Here I've just put "(...)?" around the final part of the url to make it an optional match, and changed the backreference to $2.
Of course, this actually rewrites http://www.domain.com/users/online/friends/ as:
http://www.domain.com/index.php?p=users.online.friends&page=
So your PHP code would have to check whether the page parameter is non-empty.

Answer 2

Yes, that's fine. I guess they could be combined into a single rule but there's not really any need.
You might consider leaving page as part of the URL so instead of:
http://www.domain.com/users/online/friends/22/
just have:
http://www.domain.com/users/online/friends?page=22
and then have one rule something like:
RewriteRule ^users/online/friends/?$ ./index.php?p=users.online.friends&s=8 [L,QSA]
to append the query string
Edit: There are a couple of ways of reducing the number of rewrite rules you have.
Firstly, use wildcards in the search terms, like:
RewriteRule ^users/(\w+)/(\w+)$ /index.php?p=users.$1.$2 [L,QSA]
will reduce quite a number of rules.
Secondly, if you're passing everything through /index.php just consider delegating all requests there:
RewriteRule ^(users/*)$ /index.php/$1 [L,QSA]
That rule uses a third technique: instead of passing the path information via a query string parameter, pass it via the extra path info. That can be accessed via $_SERVER['PATH_INFO'].
That being said, lots of rules isn't necessarily bad. At least it's explicit about all your actions. The thing you have to watch out for is creating a maintenance nightmare however.

Answer 3

# Initial step
RewriteCond %{QUERY_STRING} !(?:^|&)p=
RewriteRule ^([^/]+)/(.+) /$2?p=$1 [QSA]
# Subsequent steps
RewriteCond %{QUERY_STRING} ((?:[^&]*&)*?)p=([^&]*)(.*)
RewriteRule ^([^/]+)/(.+) /$2?%1p=%2.$1%3
# Last step with page number
RewriteRule ^(\d+)/?$ /index.php?page=$1 [QSA,L]
# Last step without page number
RewriteCond %{QUERY_STRING} (?:((?:[^&]*&)*?)p=([^&]*))?(.*)
RewriteRule ^([^/]+)/?$ /index.php?%1p=%2.$1%3 [L]
This would rewrite the URL in several steps:
http://www.domain.com/users/online/friends/22/
http://www.domain.com/online/friends/22/?p=users
http://www.domain.com/friends/22/?p=users.online
http://www.domain.com/22/?p=users.online.friends
http://www.domain.com/index.php?p=users.online.friends&page=22
An easier method would be the following, but would require you to change your scripts:
RewriteRule ^(.*?)(?:/(\d+))?/?$ /index.php?p=$1&page=$2 [QSA,L]
It would do everything in one step, with a little difference:
http://www.domain.com/users/online/friends/22/
http://www.domain.com/index.php?p=users/online/friends&page=22
Adding the s=8 query argument would require more work:
Creating a text-file with the menu numbers for each page.
Adding a RewriteMap directive.
Changing the second-last rule to use the same RewriteCond as the last rule has.
Adding &s=%{menumap:%2|0} to the last two rules.