# Cách để xem các quy luật rule lấy giá trị như thế nào add\_rewrite\_rule, $wp\_rewrite, $wp\_query->quer

```
// ===========
add_action('init', 'my_book_cpt');
function my_book_cpt() {
  $labels = array(
    'name'               => _x('Books', 'post type general name', 'your-plugin-textdomain'),
    'singular_name'      => _x('Book', 'post type singular name', 'your-plugin-textdomain'),
    'menu_name'          => _x('Books', 'admin menu', 'your-plugin-textdomain'),
    'name_admin_bar'     => _x('Book', 'add new on admin bar', 'your-plugin-textdomain'),
    'add_new'            => _x('Add New', 'book', 'your-plugin-textdomain'),
    'add_new_item'       => __('Add New Book', 'your-plugin-textdomain'),
    'new_item'           => __('New Book', 'your-plugin-textdomain'),
    'edit_item'          => __('Edit Book', 'your-plugin-textdomain'),
    'view_item'          => __('View Book', 'your-plugin-textdomain'),
    'all_items'          => __('All Books', 'your-plugin-textdomain'),
    'search_items'       => __('Search Books', 'your-plugin-textdomain'),
    'parent_item_colon'  => __('Parent Books:', 'your-plugin-textdomain'),
    'not_found'          => __('No books found.', 'your-plugin-textdomain'),
    'not_found_in_trash' => __('No books found in Trash.', 'your-plugin-textdomain'),
  );
  $args = array(
    'labels'             => $labels,
    'description'        => __('Description.', 'your-plugin-textdomain'),
    'public'             => true,
    'publicly_queryable' => true,
    'show_ui'            => true,
    'show_in_menu'       => true,
    'query_var'          => true,
    'has_archive'        => false,
    // 'rewrite'            => array('slug' => 'book','with_front'=>false),
    'capability_type'    => 'post',
    'hierarchical'       => false,
    'menu_position'      => null,
    'show_in_rest'       => true,
    'rest_base'          => 'book',
    'supports'           => array('title', 'editor', 'author', 'thumbnail', 'excerpt', 'comments'),
  );
  register_post_type('book', $args);
  flush_rewrite_rules(true);
}
// ===========
add_action('init', 'my_book_taxonomy', 30);
function my_book_taxonomy() {
  $labels = array(
    'name'              => _x('Genres', 'taxonomy general name'),
    'singular_name'     => _x('Genre', 'taxonomy singular name'),
    'search_items'      => __('Search Genres'),
    'all_items'         => __('All Genres'),
    'parent_item'       => __('Parent Genre'),
    'parent_item_colon' => __('Parent Genre:'),
    'edit_item'         => __('Edit Genre'),
    'update_item'       => __('Update Genre'),
    'add_new_item'      => __('Add New Genre'),
    'new_item_name'     => __('New Genre Name'),
    'menu_name'         => __('Genre'),
  );
  $args = array(
    'hierarchical'      => true,
    'labels'            => $labels,
    'show_ui'           => true,
    'show_admin_column' => true,
    'query_var'         => true,
    'rewrite'           => array('slug' => 'genre'),
    'show_in_rest'      => true,
    'rest_base'         => 'genre',
  );
  register_taxonomy('genre', array('book'), $args);
  flush_rewrite_rules(true);
}
// ====
add_action( 'init', 'pmg_rewrite_add_rewrites' );
function pmg_rewrite_add_rewrites() {
  add_rewrite_rule( 'myparamname/([a-z0-9-]+)[/]?$', 'index.php?myparamname=$matches[1]', 'top' );
}
add_filter( 'query_vars', function( $query_vars ) {
    $query_vars[] = 'myparamname';
    echo '<pre>';
			var_export($query_vars);
		echo '</pre>';
    return $query_vars;
	} 
);
add_action( 'template_include', function( $template ) {
	global $wp_rewrite;
	echo '<pre>';
		var_export($wp_rewrite);
	echo '</pre>';
	var_export(get_query_var( 'book'));
  if ( get_query_var( 'myparamname' ) == false || get_query_var( 'myparamname' ) == '' ) {
    return $template;
  }
  include get_template_directory() . '/template-name.php';
} );
```

**Ví dụ 2:**&#x20;

![](/files/Oh3XYidJkP8CDR1J8TyV)

![](/files/bGa3F1rO92J2qq3tCZFU)

![](/files/ivQGUj5w8oAOOZxGzLns)

C:\xampp\htdocs\test1\wp-content\themes\twentytwentyone\functions.php

```
// ====
add_filter('query_vars', function($vars) {
    $vars[] = "my_subscriber";
    echo '<pre>';
    	var_export( $vars);
    echo '</pre>';
    return $vars;
});
add_action('init', function() {
    $page_id = 2; // update 2 (sample page) to your custom page ID where you can get the subscriber(s) data later
    $page_data = get_post( $page_id ); 
    add_rewrite_rule(
        $page_data->post_name . '/subscriber/([^/]+)/?$',
        'index.php?pagename=' . $page_data->post_name . '&my_subscribers=100&my_subscriber=gggg',
        'top'
    );
});
```

C:\xampp\htdocs\test1\wp-content\themes\twentytwentyone\header.php

```
<?php  
echo '<pre>';
  echo "==============1";
  var_export(get_query_var( 'my_subscriber'));
  echo "==============2";
echo '</pre>';
?>
```

**Ví dụ 3: Using Custom Templates with custom querystring**

```
/**
 * Template Name: Nutritional Information
 */
get_header(); 
 
global $wp_query;
echo 'Food : ' . $wp_query->query_vars['food'];
echo '<br />';
echo 'Variety : ' . $wp_query->query_vars['variety'];
// ... more ...
get_footer();
```

> **Xem thêm tại:**
>
> [**https://developer.wordpress.org/reference/functions/add\_rewrite\_rule/**](https://developer.wordpress.org/reference/functions/add_rewrite_rule/)

**Ví dụ 2: Một ví dụ viết lại đường dẫn subpage id = 2 và lấy giá trị truyền vào dạng ?avaiable1=abac1\&avaiable2=ab**

![](/files/a3xoHreq5HMbJimfPi3B)

![](/files/IB9rPcL9zNSnNPBPeQQq)


---

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```
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