WordPress add_rewrite_rule works locally but not on server

Question

I'm able to get add_rewrite_rule to work locally with MAMP, but not on my DreamHost production server.

I'm attempting to prettify the URLs for individual pets at http://www.pawsnewengland.com/our-dogs-list/. The ugly URLs follow this structure: our-dogs-list/?view=pet-details&id=12345, and a custom function uses $_GET variables to process in the information.

In my functions.php file, I've included this:

function rewrite_pet_url() {
    add_rewrite_rule(
        "our-dogs-list/pet-details/([0-9]+)/?$",
        "index.php/our-dogs-list/?view=pet-details&id=$1",
        "top"
    );
}
add_action( 'init', 'rewrite_pet_url');

I've also tried this with the same results:

function rewrite_pet_url() {
    add_rewrite_rule(
        "our-dogs-list/pet-details/([0-9]+)/?$",
        "index.php/our-dogs-list/?view=pet-details&id=$matches[1]",
        "top"
    );
}
add_action( 'init', 'rewrite_pet_url');

And in an effort to simply test that rewrites would work at all, tried this:

function rewrite_pet_url() {
    add_rewrite_rule(
        "fake",
        "index.php/about",
        "top"
    );
}
add_action( 'init', 'rewrite_pet_url');

I'm flushing rewrite rules prior to testing, and have confirmed that the rewrite rules were added to the .htaccess file. For some reason, though, I'm seeing either a 404 page or a white screen and "No input file specified."

I'm able to get this working locally, so I have no idea what's breaking on a live server. Any insights?

Update 1

I've gotten the rewrite "working" in the sense that it no longer causes any errors. Unfortunately, it now causes an unwanted redirect to the root URL.

function rewrite_pet_url() {
    add_rewrite_tag('%view%','([^&]+)');
    add_rewrite_tag('%id%','([^&]+)');
    add_rewrite_rule(
        'our-dogs-list/pet-details/([0-9]+)?$',
        'index.php/?page_id=1663&view=pet-details&id=$1',
        'top'
    );
}
add_action( 'init', 'rewrite_pet_url' );

With this, I can access the view and id variables using get_query_var(). However, instead of honoring example.com/our-dogs-list/pet-details/12345, WordPress redirects the page to example.com/our-dogs-list/.

Any idea what could be causing that? It's effectively making the rewrite rule useless.

Answer 1

I've written a guide on how to add custom permalinks, here's the example plugin (also available at my site):

<?php
/*
Plugin Name: My Permalink Demo
Plugin URI: http://soderlind.no/archives/2012/11/01/wordpress-plugins-and-permalinks-how-to-use-pretty-links-in-your-plugin/
Description: Demo plugin to show how to implement your custom permalink for your plugin. To test, add the [mypermalink] or [mypermalink val="ipsum"] shortcode to a page or post.
Version: 1.0.1
Author: Per Soderlind
Author URI: http://soderlind.no/
*/

if (!class_exists('my_permalink')) {
    class my_permalink {

        function __construct(){
            // demo shortcode
            add_shortcode('mypermalink', array(&$this,'my_permalink_demo_shortcode'));

            // permalink hooks:
            add_filter('generate_rewrite_rules', array(&$this,'my_permalink_rewrite_rule'));
            add_filter('query_vars', array(&$this,'my_permalink_query_vars'));
            add_filter('admin_init', array(&$this, 'my_permalink_flush_rewrite_rules'));
            add_action("parse_request", array(&$this,"my_permalink_parse_request"));
        }

        /**************************************************************************
         * Demo shortcode
         * A simple shortcode used to demonstrate the plugin.
         *
         * @see http://codex.wordpress.org/Shortcode_API
         * @param array $atts shortcode parameters
         * @return string URL to demonstrate custom permalink
         **************************************************************************/
        function my_permalink_demo_shortcode($atts) {
            extract(shortcode_atts(array(
                // default values
                'val'       =>   'lorem'
            ), $atts));
            return sprintf('<a href="%s">My permalink</a>',$this->my_permalink_url($val));
        }

        /**************************************************************************
         * Create your URL
         * If the blog has a permalink structure, a permalink is returned. Otherwise
         * a standard URL with param=val.
         *
         * @param sting $val Parameter to custom url
         * @return string URL
         **************************************************************************/
        function my_permalink_url($val) {
            if ( get_option('permalink_structure')) { // check if the blog has a permalink structure
                return sprintf("%s/my-permalink/%s",home_url(),$val);
            } else {
                return sprintf("%s/index.php?my_permalink_variable_01=%s",home_url(),$val);
            }
        }

        /**************************************************************************
         * Add your rewrite rule.
         * The rewrite rules array is an associative array with permalink URLs as regular
         * expressions (regex) keys, and the corresponding non-permalink-style URLs as values
         * For the rule to take effect, For the rule to take effect, flush the rewrite cache,
         * either by re-saving permalinks in Settings->Permalinks, or running the
         * my_permalink_flush_rewrite_rules() method below.
         *
         * @see http://codex.wordpress.org/Custom_Queries#Permalinks_for_Custom_Archives
         * @param object $wp_rewrite
         * @return array New permalink structure
         **************************************************************************/
        function my_permalink_rewrite_rule( $wp_rewrite ) {
            $new_rules = array(
                 'my-permalink/(.*)$' => sprintf("index.php?my_permalink_variable_01=%s",$wp_rewrite->preg_index(1))
                 /*
                 // a more complex permalink:
                 'my-permalink/([^/]+)/([^.]+).html$' => sprintf("index.php?my_permalink_variable_01=%s&my_permalink_variable_02=%s",$wp_rewrite->preg_index(1),$wp_rewrite->preg_index(2))
                 */
            );

            $wp_rewrite->rules = $new_rules + $wp_rewrite->rules;
            return $wp_rewrite->rules;
        }

        /**************************************************************************
         * Add your custom query variables.
         * To make sure that our parameter value(s) gets saved,when WordPress parse the URL,
         * we have to add our variable(s) to the list of query variables WordPress
         * understands (query_vars filter)
         *
         * @see http://codex.wordpress.org/Custom_Queries
         * @param array $query_vars
         * @return array $query_vars with custom query variables
         **************************************************************************/
        function my_permalink_query_vars( $query_vars ) {
            $query_vars[] = 'my_permalink_variable_01';
            /*
            // need more variables?:
            $query_vars[] = 'my_permalink_variable_02';
            $query_vars[] = 'my_permalink_variable_03';
            */
            return $query_vars;
        }

        /**************************************************************************
         * Parses a URL into a query specification
         * This is where you should add your code.
         *
         * @see http://codex.wordpress.org/Query_Overview
         * @param array $atts shortcode parameters
         * @return string URL to demonstrate custom permalink
         **************************************************************************/
        function my_permalink_parse_request($wp_query) {
            if (isset($wp_query->query_vars['my_permalink_variable_01'])) { // same as the first custom variable in my_permalink_query_vars( $query_vars )
                // add your code here, code below is for this demo
                printf("<pre>%s</pre>",print_r($wp_query->query_vars,true));
                exit(0);
            }
        }

        /**************************************************************************
         * Flushes the permalink structure.
         * flush_rules is an extremely costly function in terms of performance, and
         * should only be run when changing the rule.
         *
         * @see http://codex.wordpress.org/Rewrite_API/flush_rules
         **************************************************************************/
        function my_permalink_flush_rewrite_rules() {
            $rules = $GLOBALS['wp_rewrite']->wp_rewrite_rules();
            if ( ! isset( $rules['my-permalink/(.*)$'] ) ) { // must be the same rule as in my_permalink_rewrite_rule($wp_rewrite)
                global $wp_rewrite;
                $wp_rewrite->flush_rules();
            }
        }
    } //End Class
} //End if class exists statement

if (class_exists('my_permalink')) {
    $my_permalink_var = new my_permalink();
}
?>

Answer 2

Your replacements look incorrect, try:

function rewrite_pet_url() {
    add_rewrite_rule(
        "our-dogs-list/pet-details/([0-9]+)/?$",
        "index.php?view=pet-details&id=$1",
        "top"
    );
}
add_action( 'init', 'rewrite_pet_url');

Note the use of index.php and not index.php/our-dogs-list/ as the destination.

Or maybe it's like this:

function rewrite_pet_url() {
    add_rewrite_rule(
        "our-dogs-list/pet-details/([0-9]+)/?$",
        "our-dogs-list/index.php?view=pet-details&id=$1",
        "top"
    );
}
add_action( 'init', 'rewrite_pet_url');

Answer 3

edit in your .htaccess

RewriteRule ^our-dogs-list/pet-details/([0-9]+)?$ /index.php?page_id=1663&view=pet-details&id=$1 [L] add this for RewriteRule ^index\.php$ - [L] so you .hatcces would something like:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /wordpress/
RewriteRule ^our-dogs-list/pet-details/([0-9]+)?$ /wordpress/index.php?page_id=2&view=pet-details&id=$1 [L]
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /wordpress/index.php [L]
</IfModule>

update

from: http://codex.wordpress.org/Rewrite_API/add_rewrite_rule

IMPORTANT: By default, WordPress will not recognize custom querystring variables used for rewrites. You must register your querystring variables with WordPress. Simply use add_rewrite_tag() to do this, or the above rewrite will not work! More information about capturing querystring variable values after a rewrite can be found here.

so far i understand you should use: add_rewrite_tag() for view and id in your first example.