Custom rewrite, url path with parameters to a page

Question

I'm developing a plugin, that should display content according to two optional parameters in the URL. The following URL should all be treated by the plugin:

/pluginpage/
/pluginpage/value1/
/pluginpage/value1/value2/

Now I have put in place these things:

• A page with a shortcode [myplugin] and the URL /pluginpage/
  • The shortcode that displays the content taking the parameters from the $_GET variable
  • The plugin works if the URL looks like /pluginpage/?param1=value1&param2=value2
• Two rewrite rules in place, that match the three URL patterns to the page with the shortcode

add_rewrite_rule('^(pluginpage)/(.*)/?', 'index.php?name=$matches[1]&param1=$matches[2]', 'top');
add_rewrite_rule('^(pluginpage)/(.*)/(.*)/?', 'index.php?name=$matches[1]&param1=$matches[2]&param2=$matches[3]', 'top');

The rewrite rules work, but not as expected. When navigating to /pluginpage/value1/ or /pluginpage/value1/value2/ the page with the shortcode is displayed, but there is a redirect to /pluginpage/ and the parameters are lost during the redirect.

There is a missing piece that tells wordpress to not redirect from /pluginpage/value1/ to /pluginpage/. What exactly is missing?

Or might there be a better approach by mapping the URLs directly to the plugin without using a page and a shortcode?

This question is quite similar, but the answers are lacking important details, and therefore were not helpful in my case.

Thank you for any help.

Answer 1

Your code seems to work fine with slight modifications. Taken from here: https://developer.wordpress.org/reference/functions/add_rewrite_rule/#comment-content-4787

First off, I moved the rewrite rules to init and modified the regex to match parameters optionally:

function wse_414800_rewrite_state_city() {

    add_rewrite_rule(
        '^(pluginpage)/([^/]*)/([^/]*)/?',
        'index.php?pagename=pluginpage&state=$matches[2]&city=$matches[3]',
        'top'
    );

    add_rewrite_rule(
        '^(pluginpage)/([^/]*)/?',
        'index.php?pagename=pluginpage&state=$matches[2]',
        'top'
    );
}
add_action('init', 'wse_414800_rewrite_state_city');

And, to be able to retrieve our custom query params I've added a function to register custom tags.

// Register query parameters for state and city
function wse_414800_register_query_param() {
    add_rewrite_tag('%state%', '([^&]+)');
    add_rewrite_tag('%city%', '([^&]+)');
}
add_action('init', 'wse_414800_register_query_param' );

And later on, you can retrieve the parameter either in your shortcode or in a page template using get_query_var()

For your query: "Or might there be a better approach by mapping the URLs directly to the plugin without using a page and a shortcode"

You can use a Page template as an alternative, here is an example for registering and using page template: https://developer.wordpress.org/reference/functions/add_rewrite_rule/#comment-content-4554)

Further it depends on what type of plugin you're building, if it's for internal use you can choose either of the options shortcode or template, but if you plan to publish the plugin IMHO a Gutenberg block or shortcode would do better.

function wse_414800_show_state_city_cb( $atts ) {

    $state = get_query_var('state');
    $city = get_query_var('city');

    return "State: " . esc_html( $state ) .", City: " .esc_html( $city );
}

add_shortcode( 'show_state_city', 'wse_414800_show_state_city_cb' );

You could utilize the plugin like Query Monitor to check what/how the rewrite rule is working.