Override wordpress routing / url rewriting? - wordpress

Question

I would like to serve different content based on the URL.
I started with a custom page setup via a custom template but I am open to something else.
The main goal is to have one PHP page that can serve different contents programmatically based on the URL.
For example:
https://some-url.com/my-plugin/ -> run my page
https://some-url.com/my-plugin/foo/ -> run my page
https://some-url.com/my-plugin/foo2/abc/ -> run my page
etc...
I have been looking at add_rewrite_rule, add_rewrite_tag, flush_rewrite_rules and WP_Rewrite API but I am getting confused about which one I should use?
I found an example here but I could not make it work, I get 404s, any idea why?:
/*
Plugin Name: Products Plugin
Plugin URI: http://clivern.com/
Description: Register URL rules for our products
Version: 1.0
Author: Clivern
Author URI: http://clivern.com
License: MIT
*/
function products_plugin_activate() {
products_plugin_rules();
flush_rewrite_rules();
}
function products_plugin_deactivate() {
flush_rewrite_rules();
}
function products_plugin_rules() {
add_rewrite_rule('products/?([^/]*)', 'index.php?pagename=products&product_id=$matches[1]', 'top');
}
function products_plugin_query_vars($vars) {
$vars[] = 'product_id';
return $vars;
}
function products_plugin_display() {
$products_page = get_query_var('pagename');
$product_id = get_query_var('product_id');
if ('products' == $products_page && '' == $product_id):
//show all products
exit;
elseif ('products' == $products_page && '' != $product_id):
//show product page
exit;
endif;
}
//register activation function
register_activation_hook(__FILE__, 'products_plugin_activate');
//register deactivation function
register_deactivation_hook(__FILE__, 'products_plugin_deactivate');
//add rewrite rules in case another plugin flushes rules
add_action('init', 'products_plugin_rules');
//add plugin query vars (product_id) to wordpress
add_filter('query_vars', 'products_plugin_query_vars');
//register plugin custom pages display
add_filter('template_redirect', 'products_plugin_display');

Answer 1

First of all, make sure your pretty permalinks are enabled, in this case the option "Plain" in Settings - Permalinks should be unselected:
Select one of these options to enable pretty permalinks
You can check whether pretty permalinks are enabled in the code like so:
function is_enabled_pretty_permalinks() {
return !empty( get_option( 'permalink_structure' ) );
}
if ( is_enabled_pretty_permalinks() ) {
echo 'Pretty permalinks enabled';
}
Next add a new rewrite rule:
function add_my_rewrite_rule() {
$page_slug = 'products'; // slug of the page you want to be shown to
$param = 'do'; // param name you want to handle on the page
add_rewrite_rule('my-plugin/?([^/]*)', 'index.php?pagename=' . $page_slug . '&' . $param . '=$matches[1]', 'top');
}
add_action('init', 'add_my_rewrite_rule');
Add your parameter to query vars so you will be able to handle it on the page:
function add_my_query_vars($vars) {
$vars[] = 'do'; // param name you want to handle on the page
return $vars;
}
add_filter('query_vars', 'add_my_query_vars');
Then you can access your query var do in the page template or in a shortcode, for example:
function my_plugin_shortcode_handler( $atts ){
$do = get_query_var( 'do' );
if ( $do === 'this' ) {
return 'do this';
} else {
return 'do that';
}
}
add_shortcode( 'myshortcode', 'my_plugin_shortcode_handler' );
Then place the shortcode to the content via Gutenberg.
Check out the links:
https://some-url.com/my-plugin/this/ - outputs "do this"
https://some-url.com/my-plugin/that/ - outputs "do that".

Answer 2

This can be solved by using query params. Like you mentioned you have set up custom page via a custom template. You can read the URL and check for the parameters and based on that you can send data from the PHP template page.
e.g,
function cleanTheInput($data) {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
$data = htmlentities($data);
return $data;
}
if (isset($_GET['page_url'])) {
$theUrl = cleanTheInput($_GET['page_url']);
}
if($theUrl == 266)){
// data for https://some-url.com/?page_url=266
}
if($theUrl == 366)){
// data for https://some-url.com/?page_url=366
}