Custom Posts Types using Posts Category

Question

I'm using some custom posts types, and, I don't wanna create specific categories for each one.

I'd like to use the Post Category in all my Custom Post.

Here is a example of my new custom posts type:

I know how create new category type for my custom posts, but I don't know how use the regular categories from posts.

/*  New Custom Post - Cupons
/* ------------------------------------ */

add_action( 'init', 'create_post_type_cupons' );
function create_post_type_cupons() {
    register_post_type( 'cupom',
        array(
            'labels' => array(
                'name' => __( 'Cupons' ),
                'singular_name' => __( 'Cupom' )
            ),
            'public' => true,
        )
    );
}

Answer 1

The documentation for register_post_type mentions a taxonomies parameter, giving it a value of array( 'category' ) will do what you want.

There is also the register_taxonomy_for_object_type function

Answer 2

After

'public' => true,

you add

'taxonomies' => array('category','post_tag'),

this one create category and tag for your custom post type if you want just category the delete ,'post_tag'.

Answer 3

I added the function register_taxonomy_for_object_type( $taxonomy, $object_type ) in functions.php.

First: I need to choose which kind of taxonomy I want, in this case, "category".

Second: I choose the object type, in this case, "cupom" that is my Custom Post Type.

add_action('init','add_categories_to_cupom');
function add_categories_to_cupom(){
    register_taxonomy_for_object_type('category', 'cupom');
}

So now, my Custom Post Type "cupom" uses the the Posts Category.