Wordpress Category for pages - php

Question

I'm having a problem with receiving the value from %category% in $wp_rewrite->page_structure :
function custom_page_rules() {
global $wp_rewrite;
$wp_rewrite->page_structure = $wp_rewrite->root .'/%category%/%pagename%';
//flush_rewrite_rules();
}
add_action( 'init', 'custom_page_rules',1 );
How can I receive the %category% in a $wp_rewrite->page_structure?
Now it returns:
http://example.com/%category%/the-page-slug/
Instead:
http://example.com/my-cat-slug/the-page-slug/
Note Categories for pages are working well:
http://example.com/my-cat-slug/
returns all pages from this category.

Answer 1

A solution could be:
function rudr_post_permalink( $url, $post ){
if( !is_object( $post ) )
$post = get_post( $post_id );
$replace = $post->post_name;
/* We should use a post ID to make a replacement. It is required if you use urf-8 characters in your URLs */
if( $post->ID == 1 )
$replace = 'hello-planet';
if( $post->ID == 12 )
$replace = 'Contacts';
$url = str_replace($post->post_name, $replace, $url );
return $url;
}
add_filter( 'post_link', 'rudr_post_permalink', 'edit_files', 2 );
add_filter( 'page_link', 'rudr_post_permalink', 'edit_files', 2 );
add_filter( 'post_type_link', 'rudr_post_permalink', 'edit_files', 2 );
Which is explained here
You can change the if( $post->ID == 1 ) to anything you need.
I have changed the whole code to add categories in the URL's when it are pages.
Regards, Danny