Blogging Tips

There’s one question that a lot of people have asked over time about using WordPress, but there’s not really a clear cut answer. How can you remove the Category Base from your WordPress permalinks? This may not be a major concern for a standard blog site, but it may be of use to some, and I think it’s definitely more use to those using WordPress as a CMS.

My method so far works for a permalink structure of /%category%/%post-name%/. Without any modifications, this will give a permalink link such as /category/post-category/post-name/. However, since at least WordPress 2.6, going to /post-category/post-name/ without the initial category ‘directory’ in place, has worked with this permalink structure. This is due to the internal working of WordPress.

Removing the category base isn’t part of WordPress as it’s not advised to be used. If you have a category called ‘news’ and a page called ‘news’, which one is to be displayed when you go to http://www.domain.com/news/ ? So I can understand the reasons behind it not being readily available to remove the category base, however if you’re in control of your own site and keep that in mind, then I don’t see any reason why you can’t remove the base.

So where do we start? Well first off you need to check your permalinks settings. This will only work (at present) if you have the structure mentioned above. So if you go to Settings -> Permalinks and ensure you have a custom permalink set up of

/%category%/%post-name%/

If you want to do this on a pre-existing site and that isn’t your structure then you would be best off not proceeding with this method as I wouldn’t advise changing your structure unless you have just a handful of pages. If you do change your structure then you need to also be creating a .htaccess redirect for each post!

What we then need to do is remove the base from the permalinks. We can do this in our functions.php theme file using the filter and function below:

[sourcecode language="php"]add_filter(‘user_trailingslashit’, ‘remcat_function’);
function remcat_function($link) {
return str_replace(“/category/”, “/”, $link);
}[/sourcecode]

This takes every permalink and removes the /category/ ‘directory’ from it. If you’ve changed your category base name then it’s unlikely you’ll be wanting to do this anyway, but if you do, then just change line 4 from /category/ to which ever base name you’ve used (surrounded by the forwardslashes of course).

Now, on the front end of your site, your category listings, blog posts and ‘filed under’ post meta data should contain links to the category or posts without the category directory within them. At this point, most of your site should continue to function as usual, minus the category base, and a lot of the methods I found were fine up to this point too, however a lot of people had trouble with viewing a category page and then trying to go to page 2 eg. /category-name/page/2/. It didn’t work.

So to fix this we need to make use of WordPress’s internal rewrite, and bit like mod rewrite, so that it keeps the correct URL in the address bar but loads the correct page too.

First of all we need to regenerate the rewrite rules already written using the flush_rules() function. We do this on initialisation of the page using the action and function below (again this goes in your functions.php theme file)

[sourcecode language="php"]add_action(‘init’, ‘remcat_flush_rules’);
function remcat_flush_rules() {
global $wp_rewrite;
$wp_rewrite->flush_rules();
}[/sourcecode]

Finally we need to tell WordPress which page to actually load if someone has gone to page X of a category. To do this we use the filter and function below.

[sourcecode language="php"]add_filter(‘generate_rewrite_rules’, ‘remcat_rewrite’);
function remcat_rewrite($wp_rewrite) {
$new_rules = array(‘(.+)/page/(.+)/?’ => ‘index.php?category_name=’.$wp_rewrite->preg_index(1).’&paged=’.$wp_rewrite->preg_index(2));
$wp_rewrite->rules = $new_rules + $wp_rewrite->rules;
}[/sourcecode]

Here the important line is line 3:

$new_rules = array('(.+)/page/(.+)/?' => 'index.php?category_name='.$wp_rewrite->preg_index(1).'&paged='.$wp_rewrite->preg_index(2));

The array key dictates the pattern of the URL we want to be checked, and the array value specifies the URL to actually display. In this case we could have a URL of /news/page/3/ and then we’re saying to display the page index.php?category_name=news&paged=3 which is the true URL.

.htaccess Redirects

Finally, if this site is not a brand new site then you want to ensure that anyone going to the old url with the category base in is redirected through to the new version. We do this with a redirect rewrite, to match the URL containing the category base and then remove it and redirect the user to the new URL. You need to have mod rewrite enabled on your server for this and can use the following code

[sourcecode language="html"]RewriteRule ^category/(.+)$ /$1 [R=301,L][/sourcecode]

Place the above code after your RewriteEngine code, which should be present for Permalinks anyway ie.

[sourcecode language="html"]# BEGIN WordPress

RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

# END WordPress

RewriteRule ^category/(.+)$ /$1 [R=301,L][/sourcecode]

Again, if you have a base other than ‘category’ then you’ll have to change the last line above to reflect that. Also, if you’ve installed WordPress within a directory within the root eg. ‘wp’ or ‘news’, then you need to change the last line to

[sourcecode language="html"]RewriteRule ^wp/category/(.+)$ /wp/$1 [R=301,L][/sourcecode]

Which includes a directory of ‘wp’.

Conclusion

I wouldn’t recommend that you take this straight to a live site but test it on a test install first. Not because it doesn’t work, but there are a lot of instructions to follow! I hope to extend this to not be dependent on the permalink structure hopefully for next week.