Is it possible to have dynamic post id # in add_menu_page()?

Question

I use the add_menu_page function in my custom theme builds but when I export my local copy of the site and import it in the production site some of post id numbers change and I have to update this function manually (ie: in the code below: ?post=8, ?post=8, ?post=10). Is there a way to have these numbers be dynamic?

function custom_admin_menu_links() {
    $user = wp_get_current_user();
    if ( ! $user->has_cap( 'manage_options' ) ) {
        add_menu_page( 'Home', 'Home', 'edit_posts', 'post.php?post=6&action=edit', '', 'dashicons-admin-home', 1);
        add_menu_page( 'About', 'About', 'edit_posts', 'post.php?post=8&action=edit', '', 'dashicons-id', 2);
        add_menu_page( 'Contact', 'Contact', 'edit_posts', 'post.php?post=10&action=edit', '', 'dashicons-phone', 3);
    }
}
add_action( 'admin_menu', 'custom_admin_menu_links' );

Answer 1

There is a function called get_page_by_title that accepts a post title and returns the ID of that post. You might even use it in conjunction with get_edit_post_link by passing the ID and retrieve the edit link.

However, how can you be sure the post's title will never change? You could go a little further and add a settings page where you would map a particular post / page to an entity such as HOME_ID, ABOUT_ID etc. Then, instead of using the get_page_by_title you would just have this settings array and you could build those add_menu_page calls like this:

if ( ! $user->has_cap( 'manage_options' ) ) {
    $options = get_option( 'wt_menu_post_ids', array() );

    add_menu_page( 'Home', 'Home', 'edit_posts', get_edit_post_link( $options['HOME_ID'] ), '', 'dashicons-admin-home', 1);
    // [...]
}

Answer 2

The quick and dirty answer would be something like this:

function custom_admin_menu_links() {
  $user = wp_get_current_user();
  if (  $user->has_cap( 'manage_options' ) ) {
    $type = 'book';

    $page = get_page_by_title('home','object',$type);
    if (!empty($page)) {
      add_menu_page( 'Home', 'Home', 'edit_posts', 'post.php?post='.$page->ID.'&action=edit', '', 'dashicons-admin-home', 1);
    }

    $page = get_page_by_title('About','object',$type);
    if (!empty($page)) {
      add_menu_page( 'About', 'About', 'edit_posts', 'post.php?post=8&action=edit', '', 'dashicons-id', 2);
    }

    $page = get_page_by_title('Contact','object',$type);
    if (!empty($page)) {
      add_menu_page( 'Contact', 'Contact', 'edit_posts', 'post.php?post=10&action=edit', '', 'dashicons-phone', 3);
    }
  }
}
add_action( 'admin_menu', 'custom_admin_menu_links' );

But you are running a lot of queries on every admin page load. You really should work out a way to cache the results. Something like:

function cache_custom_admin_menu_links($post_ID, $post) {
  $links = get_option('my_menu_links');

  $keys = array(
    'home',
    'about',
    'contact'
  );

  if (in_array($post->post_name,$keys)) {
    $links[$post->post_name] = $post_ID;

    update_option('my_menu_links',$links);
  }
}
add_action('save_post','cache_custom_admin_menu_links',10,2);

function custom_admin_menu_links() {
  $user = wp_get_current_user();

  if (  $user->has_cap( 'manage_options' ) ) {
    $type = 'book';
    $links = get_option('my_menu_links');
    $i = 1;
    foreach ($links as $k=>$v) {
      add_menu_page( $k, ucfirst($k), 'edit_posts', 'post.php?post='.$v.'&action=edit', '', 'dashicons-phone', $i);
      $i++;
    }
  }
}
add_action( 'admin_menu', 'custom_admin_menu_links' );

Then you just have to resave your posts rather than edit the code. I am sure even that could be automated if you needed it to be.