Add Custom Post Type Slugs to Admin Body Class

常見問題

What does this do, exactly?

• Additional CSS classes are added to the HTML body tag when certain pages load in Admin mode

What classes?

• If you are in WP Admin, if you click Posts, you will see a list of all your Posts, and the CSS class edit-list-post
  will be added to the HTML body tag. If you click a specific Post, you will enter the edit page for that Post,
  and the CSS class edit-page-post will be added to the HTML body tag. Note the difference between the two:
  edit-list-post vs. edit-page-post, list vs. page
  Similarly, if you click Pages, the same thing as above will happen, except the word post will be replaced with
  the word page in each of the CSS classes. Futher, if you have custom post types, the word post will be replaced
  with whatever your custom post type is, so a custom post type called “Movies” will results in the following CSS classes
  being added:
  edit-list-movie vs. edit-page-movie

Why would I want to do this?

• Really only if you used some custom CSS or JS in your WP Admin. You could color the List or Edit headers or
  backgrounds differently, add custom validation to some fields, etc. Maybe when you are viewing the list of Posts,
  you want to see red column and field headers, blue when viewing Pages, and green when viewing Movies, and for the
  Movies Edit page, you have a custom field that you want to validate as some specific format, like a date or number,
  you could add custom JS just for that page, all based on these new classes on the HTML body tag.