This is the reason why your dashboard icons have changed. With 3.8, the dashboard icons are actually a font. For example, if you do a firebug inspection, you will see that the “posts” icon is “\f109”. From what I have read, by doing this, the icons load faster and are now responsive in size as a font. Also, you don’t have to have a hover image because it is a font, it will automatically change according to your color scheme.
Here is a link to the icons created by MP6 (the developers of the new dashboard). https://melchoyce.github.io/dashicons/
So to use the dashicons, there are a couple of steps you need to take:
When you register your post type you need to add the following line of code:
'menu_icon' => '',
So for example your code would look like this:
$args = array(
'labels' => $labels,
'public' => true,
'menu_icon' => '',
'publicly_queryable' => true,
'show_ui' => true,
'show_in_menu' => true,
'query_var' => true,
'rewrite' => true,
'capability_type' => 'post',
'has_archive' => true,
'hierarchical' => false,
'menu_position' => null,
'supports' => array('title', 'editor', 'thumbnail')
);
register_post_type('cptname',$args);
}
Doing this, adds a class to your custom post type. Now we can add a function to tell wordpress to use the new css.
function cptname_post_type_css() {
echo "<style type='text/css' media='screen'>
#adminmenu .menu-icon-cptname div.wp-menu-image:before {
content: '\\f307';
}
</style>";
}
add_action('admin_head', 'cptname_post_type_css');
Just change cptname to be the name of your custom post type.
This can all be added to your themes functions.php file or you can do it through a custom plugin.
There is also some documentation over at https://hofmannsven.com/2013/laboratory/wordpress-dashicons/ that show how to create your own custom icons that you can upload to your site as well.
Hope this helps.
