How can I add single catogory for custom post type?

Question

I am add new post type called journal using below code it works fine. But I now I need to add a single category for this post type. That is I have two types of journal category normal journal and featured journals. But my blog post has some more categories I need to display only normal journal and featured journals on my journal list how can I do this. I am newbie in Wordpress coding. Thanks.

function post_type_journal()
    {
        $args = array(
            'labels' => array(
                'name' => 'Journals',
                'singular_name' => 'Journal',
                'add_new' => 'Add new journal',
                'edit_item' => 'Edit journal',
                'new_item' => 'New journal',
                'view_item' => 'View journal',
                'search_items' => 'Search journal',
                'not_found' => 'No journals found',
                'not_found_in_trash' => 'No journals found in Trash'
            ),
            'public' => true,
            'supports' => array(
                'title',
                'editor',
                'author',
                'comments'
            ),
            'taxonomies' => array('category') // this is IMPORTANT
        );
        register_post_type('Journal', $args);
    }
    add_action('init','post_type_journal');

Answer 1

You can add this line to the code which registers your Custom Post Type:

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

Or you could add Taxonomies rather than categories:

add_action( 'init', 'cpt_type_taxonomy' );
function cpt_type_taxonomy() {

register_taxonomy( 'portfolio-type', 'portfolio',
    array(
        'labels' => array(
            'name'          => _x( 'Types', 'taxonomy general name', 'theme' ),
            'add_new_item'  => __( 'Add New Portfolio Type', 'theme' ),
            'new_item_name' => __( 'New Portfolio Type', 'theme' ),
        ),
        'exclude_from_search' => true,
        'has_archive'         => true,
        'hierarchical'        => true,
        'rewrite'             => array( 'slug' => 'portfolio-type', 'with_front' => false ),
        'show_ui'             => true,
        'show_tagcloud'       => false,
    )
);

}

Then add this line to the code which registers your Custom Post Type.

'taxonomies'   => array( 'portfolio-type' ),

Here's all the code which registers a Custom Post Type:

add_action( 'init', 'register_custom_post_type' );
function register_custom_post_type() {

register_post_type( 'portfolio',
    array(
        'labels' => array(
            'name'          => __( 'Portfolio', 'theme' ),
            'singular_name' => __( 'Portfolio', 'theme' ),
        ),
        'has_archive'  => true,
        'hierarchical' => true,
        'menu_icon'    => 'dashicons-icon-name',
        'public'       => true,
        'rewrite'      => array( 'slug' => 'portfolio', 'with_front' => false ),
        'supports'     => array( 'title', 'editor', 'author', 'thumbnail', 'excerpt', 'trackbacks', 'custom-fields', 'revisions', 'page-attributes' ),
        'taxonomies'   => array( 'portfolio-type' ),

    )
);

}

Answer 2

Categories are actually a "taxonomy" for the post post type, so you need to add a new taxonomy (eg 'People') for your Journal post type.

eg:

    function people_init() {
// create a new taxonomy
register_taxonomy(
    'people',
    'journal',
    array(
        'label' => __( 'People' ),
        'rewrite' => array( 'slug' => 'person' ),
        'capabilities' => array(
            'assign_terms' => 'edit_guides',
            'edit_terms' => 'publish_guides'
        )
    )
);
}
add_action( 'init', 'people_init' );

See here for more info on taxonomies.

Answer 3

Or you can use

<?php register_taxonomy_for_object_type( 'category', 'Journals' ); ?>

to map the categories to your custom post type.

http://codex.wordpress.org/Function_Reference/register_taxonomy_for_object_type