WordPress's rewrite rules are URL rewrite configurations on the server, used to convert beautiful URLs into actual requests. Its working mechanism is to convert addresses like /about into real requests such as index.php?pagename=about through Apache or Nginx modules. 1. WordPress automatically generates rules when saving a permalink, and creates regular expressions to match URLs according to the article type and structure; 2. The rules can be refreshed manually through flush_rewrite_rules(), but they should only be used if necessary such as plug-in activation; 3. If a permalink error occurs, check whether the server enables mod_rewrite, whether the .htaccess file exists, and whether Nginx is configured correctly; 4. Custom rules can use the add_rewrite_rule() function and register query variables; 5. After modifying the rule, you must save the permalink once to take effect. Mastering these mechanisms can help solve 404 problems and implement flexible URL structures.

Understanding WordPress rewrite rules is not actually mysterious. The key is to figure out how it converts beautiful URLs into requests that can actually be processed. WordPress itself provides very friendly permalink settings, but what really works behind it is these rewrite rules. They determine how WordPress recognizes and loads the corresponding content when a user accesses a "pseudo-static" address.

What are WordPress rewrite rules?

WordPress rewrite rules are essentially URL rewrite configurations on servers such as Apache or Nginx, which are used to convert "good-looking" URLs like /about to real requests like index.php?pagename=about . These rules are automatically generated by WordPress and usually you don't need to modify them manually, but in some cases (such as custom structures, plug-in conflicts, or different server environments), it is useful to understand how they work.

Common situations include:

• Unable to access after setting up a custom article type
• 404 appears after the permalink changes
• The rules added by the plugin do not work

How does WordPress generate rewrite rules?

WordPress rewrite rules each time you save the permalink settings. It will generate a series of regular expressions to match the URL based on the current article type, taxonomy, archive structure, etc., and specify the corresponding query variables.

For example, if you set a permalink to /year/postname , WordPress will generate a rule like this:

 ^([0-9]{4})/([^/] )/?$ → index.php?year=$matches[1]&name=$matches[2]

This means that when a user accesses /2024/hello-world , the system will parse it into an article page called hello-world released in 2024.

You can refresh these rules manually by calling flush_rewrite_rules() , but only when plugin activation or theme switching , don't call it frequently, as it will affect performance.

Frequently Asked Questions and Troubleshooting Methods

Sometimes you will find that you set a permalink but return a 404 page. This is usually not a WordPress pot, but the server is not loading rewrite rules correctly.

The checkpoints are as follows:

• Is mod_rewrite enabled in Apache?
• Is there a .htaccess file? Is permissions writable?
• Is Nginx configured with correct rewrite rules?

If it is Apache, the content of the .htaccess file is roughly as follows:

 <IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

If it is Nginx, you need to add something like the following in the configuration file:

 location / {
    try_files $uri $uri/ /index.php?$args;
}

Tips for customizing rewrite rules

Sometimes you want certain URL structures to point to specific functions, such as /events/2024/january to display an active archive, you can use the add_rewrite_rule() function to customize the rules.

To give a simple example, add in functions.php of the topic:

 function my_custom_rewrite_rule() {
    add_rewrite_rule('^events/([0-9]{4})/([az] )/?', 'index.php?event_year=$matches[1]&event_month=$matches[2]', 'top');
}
add_action('init', 'my_custom_rewrite_rule');

Don't forget to register new query variables at the same time:

 function my_custom_query_vars($vars) {
    $vars[] = 'event_year';
    $vars[] = 'event_month';
    return $vars;
}
add_filter('query_vars', 'my_custom_query_vars');

This way you can use $wp_query->get('event_year') and $wp_query->get('event_month') in the template to get the parameters.

Basically that's it. Mastering WordPress rewrite rules can not only help you solve some common 404 problems, but also make you more flexible when making custom structures. But don’t forget, after each change of the rules, remember to go to the background to "save a permalink" or the new rules will not take effect.

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