project-custom-post-type.php

<?php
function projects_init() {
	register_post_type( 'projects', array(
		'labels'            => array(
			'name'                => __( 'Projects', 'twentytwenty-child' ),
			'singular_name'       => __( 'Project', 'twentytwenty-child' ),
			'all_items'           => __( 'All Projects', 'twentytwenty-child' ),
			'new_item'            => __( 'New Project', 'twentytwenty-child' ),
			'add_new'             => __( 'Add New', 'twentytwenty-child' ),
			'add_new_item'        => __( 'Add New Project', 'twentytwenty-child' ),
			'edit_item'           => __( 'Edit Project', 'twentytwenty-child' ),
			'view_item'           => __( 'View Project', 'twentytwenty-child' ),
			'search_items'        => __( 'Search Projects', 'twentytwenty-child' ),
			'not_found'           => __( 'No Projects found', 'twentytwenty-child' ),
			'not_found_in_trash'  => __( 'No Projects found in trash', 'twentytwenty-child' ),
			'parent_item_colon'   => __( 'Parent Project', 'twentytwenty-child' ),
			'menu_name'           => __( 'Projects', 'twentytwenty-child' ),
		),
		'public'            => true,
		'hierarchical'      => false,
		'show_ui'           => true,
		'show_in_nav_menus' => true,
		'supports'          => array( 'title', 'editor' ),
		'has_archive'       => true,
		'rewrite'           => true,
		'query_var'         => true,
		'menu_icon'         => 'dashicons-editor-ul',
		'show_in_rest'      => true,
		'rest_base'         => 'projects',
		'rest_controller_class' => 'WP_REST_Posts_Controller',
	) );

}
add_action( 'init', 'projects_init' );

function projects_updated_messages( $messages ) {
	global $post;

	$permalink = get_permalink( $post );

	$messages['projects'] = array(
		0 => '', // Unused. Messages start at index 1.
		1 => sprintf( __('Project updated. <a target="_blank" href="%s">View Project</a>', 'twentytwenty-child'), esc_url( $permalink ) ),
		2 => __('Custom field updated.', 'twentytwenty-child'),
		3 => __('Custom field deleted.', 'twentytwenty-child'),
		4 => __('Project updated.', 'twentytwenty-child'),
		/* translators: %s: date and time of the revision */
		5 => isset($_GET['revision']) ? sprintf( __('Project restored to revision from %s', 'twentytwenty-child'), wp_post_revision_title( (int) $_GET['revision'], false ) ) : false,
		6 => sprintf( __('Project published. <a href="%s">View Project</a>', 'twentytwenty-child'), esc_url( $permalink ) ),
		7 => __('Project saved.', 'twentytwenty-child'),
		8 => sprintf( __('Project submitted. <a target="_blank" href="%s">Preview Project</a>', 'twentytwenty-child'), esc_url( add_query_arg( 'preview', 'true', $permalink ) ) ),
		9 => sprintf( __('Project scheduled for: <strong>%1$s</strong>. <a target="_blank" href="%2$s">Preview Project</a>', 'twentytwenty-child'),
		// translators: Publish box date format, see http://php.net/date
		date_i18n( __( 'M j, Y @ G:i' ), strtotime( $post->post_date ) ), esc_url( $permalink ) ),
		10 => sprintf( __('Project draft updated. <a target="_blank" href="%s">Preview Project</a>', 'twentytwenty-child'), esc_url( add_query_arg( 'preview', 'true', $permalink ) ) ),
	);

	return $messages;
}
add_filter( 'post_updated_messages', 'projects_updated_messages' );


function project_category_init() {
	register_taxonomy( 'project-category', array( 'projects' ), array(
		'hierarchical'          => false,
		'public'                => true,
		'show_in_nav_menus'     => true,
		'show_ui'               => true,
		'show_admin_column'     => false,
		'query_var'             => true,
		'rewrite'               => true,
		'capabilities'          => array(
			'manage_terms' => 'edit_posts',
			'edit_terms'   => 'edit_posts',
			'delete_terms' => 'edit_posts',
			'assign_terms' => 'edit_posts'
		),
		'labels'                => array(
			'name'                       => __( 'Category', 'twentytwenty-child' ),
			'singular_name'              => _x( 'Categories', 'taxonomy general name', 'twentytwenty-child' ),
			'search_items'               => __( 'Search category', 'twentytwenty-child' ),
			'popular_items'              => __( 'Popular category', 'twentytwenty-child' ),
			'all_items'                  => __( 'All category', 'twentytwenty-child' ),
			'parent_item'                => __( 'Parent categories', 'twentytwenty-child' ),
			'parent_item_colon'          => __( 'Parent categories:', 'twentytwenty-child' ),
			'edit_item'                  => __( 'Edit categories', 'twentytwenty-child' ),
			'update_item'                => __( 'Update categories', 'twentytwenty-child' ),
			'add_new_item'               => __( 'New categories', 'twentytwenty-child' ),
			'new_item_name'              => __( 'New categories', 'twentytwenty-child' ),
			'separate_items_with_commas' => __( 'Separate category with commas', 'twentytwenty-child' ),
			'add_or_remove_items'        => __( 'Add or remove category', 'twentytwenty-child' ),
			'choose_from_most_used'      => __( 'Choose from the most used category', 'twentytwenty-child' ),
			'not_found'                  => __( 'No category found.', 'twentytwenty-child' ),
			'menu_name'                  => __( 'Category', 'twentytwenty-child' ),
		),
		'show_in_rest'          => true,
		'rest_base'             => 'project-category',
		'rest_controller_class' => 'WP_REST_Terms_Controller',
	) );

}

add_action( 'init', 'project_category_init' );