How to enable a custom post type to custom user role in WordPress

Question

I have created a custom post type called Course Documents using WordPress Custom Post Type UI plugin. Also, I have created a new user role called Teacher.

add_role('rpt_teacher',
            'Teacher',
            array(
                'read' => true,
                'edit_posts' => false,
                'delete_posts' => false,
                'publish_posts' => false,
                'upload_files' => true,
            )
        );

And now I want to enable the custom post type in teacher dashboard nav menu. I have used below code in my functions.php but nothing happens. How can I resolve my issue?

add_action('admin_init','rpt_add_role_caps',999);
    /**
    add teachers capability
    */
    function rpt_add_role_caps() {

        // Add the roles you'd like to administer the custom post types
        $roles = array('rpt_teacher','editor','administrator');

        // Loop through each role and assign capabilities
        foreach($roles as $the_role) {    
             $role = get_role($the_role);               
             $role->add_cap( 'read' );
             $role->add_cap( 'read_course_document');
             $role->add_cap( 'edit_course_document' );
             $role->add_cap( 'edit_course_documents' );
             $role->add_cap( 'edit_published_course_documents' );
             $role->add_cap( 'publish_course_documents' );
             $role->add_cap( 'delete_published_course_documents' );
        }
        }

Answer 1

I don't think the plugin adds the capabilities you are using in add_cap while registering the post type.

You can modify the registered post type by adding code to themes functions.php file. You can do something like this.

/**
 * Overwrite args of custom post type registered by plugin
 */
add_filter( 'register_post_type_args', 'change_capabilities_of_course_document' , 10, 2 );

function change_capabilities_of_course_document( $args, $post_type ){

 // Do not filter any other post type
 if ( 'course_document' !== $post_type ) {

     // Give other post_types their original arguments
     return $args;

 }

 // Change the capabilities of the "course_document" post_type
 $args['capabilities'] = array(
            'edit_post' => 'edit_course_document',
            'edit_posts' => 'edit_course_documents',
            'edit_others_posts' => 'edit_other_course_documents',
            'publish_posts' => 'publish_course_documents',
            'read_post' => 'read_course_document',
            'read_private_posts' => 'read_private_course_documents',
            'delete_post' => 'delete_course_document'
        );

  // Give the course_document post type it's arguments
  return $args;

}

Then you can do

/**
add teachers capability
*/
add_action('admin_init','rpt_add_role_caps',999);

function rpt_add_role_caps() {

    $role = get_role('teacher');               
    $role->add_cap( 'read_course_document');
    $role->add_cap( 'edit_course_document' );
    $role->add_cap( 'edit_course_documents' );
    $role->add_cap( 'edit_other_course_documents' );
    $role->add_cap( 'edit_published_course_documents' );
    $role->add_cap( 'publish_course_documents' );
    $role->add_cap( 'read_private_course_documents' );
    $role->add_cap( 'delete_course_document' );


}

You don't need to add capability to administrator and editor because the capability_type is post by default while registering Custom Post Type via this plugin. You can change it, if you prefer to have custom capability_type based on other post type.

Note: Make sure Show in Menu is set to true. It is true by default in this plugin.

Answer 2

The way I see it, you are on the right track. You created a user and assign new capabilities to it. You just missed specifying that the new capabilities will be used to edit your custom post type.

I have never used a plugin to create a custom post type so I am not sure how to do that using a plugin. But if you are willing to create your CPT via code you can use the following:

add_action( 'init', 'psp_register_cpt_projects');
function psp_register_cpt_projects() {
     $args = array(
 'label'               => __( 'course_documents', 'course_documents' ),
 'description'         => __( 'Course document', 'course_document' ),
 'supports'            => array( 'title', 'comments', 'revisions', ),
 'hierarchical'        => false,
 'public'              => true,
 'show_ui'             => true,
 'capability_type'     => array('course_document','course_documents'),
 'map_meta_cap'        => true,
 );
 register_post_type( 'course_documents', $args );
}

Note: This is just a basic code for creating a CPT. Please read this doc in the codex to understand it thoroughly.

Let me know if this helps you.

Answer 3

I just allowed all users to show in the 'Author' selection:

add_filter( 'wp_dropdown_users_args', 'add_subscribers_to_dropdown', 10, 2 );
function add_subscribers_to_dropdown( $query_args, $r ) {
    $query_args['who'] = '';
    return $query_args;
}

Answer 4

Just one thing I spent a couple of hours on worth mentioning. If you have custom capabilities, and you want to update a custom role capabilities, don't do it in the add_role function.

For example, this won't update the role as it already exists:

    $role = add_role(
        'client',
        'Client',
        array(
            'read' => true,
            'edit_posts' => true,
            'delete_posts' => false,
            CAP_READ_ADDRESS => true,
            CAP_DELETE_ADDRESS => true,
            CAP_EDIT_OTHER_ADDRESSES => true,
            CAP_READ_PRIVATE_ADDRESS => true,
            CAP_EDIT_ADDRESSES => true,
            CAP_PUBLISH_ADDRESS => true,
            CAP_EDIT_ADDRESS => true
        )

After any capabilities update, my client role won't get updated as it already exists.

The safest way to add custom capabilities to a custom role is to get the role and add them after add_role

function addCaps() {
    $role = get_role('client');
    $role->add_cap(CAP_READ_ADDRESS, true);
    $role->add_cap(CAP_EDIT_ADDRESSES, true);
}

add_action('admin_init', 'addCaps');