WordPress: Hide specific post editing meta boxes

hide-meta-boxes.php

<?php

$this->_add_action( 'current_screen', 'maybe_hide_meta_boxes' );

/**
 * Hides various meta boxes if they have not already been hidden.
 * Users can still unhide the meta box and it will not be hidden in
 * the future.
 *
 * @param WP_Screen $screen The current screen object.
 *
 * @return void
 */
public function maybe_hide_meta_boxes( $screen ) {

	if ( empty( $screen->post_type ) ) {
		return;
	}

	// Get a list of meta boxes to hide for this screen (post type).
	$metabox_slugs = apply_filters( 'theme_name_hide_meta_boxes_' . $screen->post_type, array(), $screen );

	if ( is_array( $metabox_slugs ) ) {
		foreach ( array_filter( $metabox_slugs ) as $metabox_slug ) {
			$hidden_key = 'theme_name_hidden_' . $metabox_slug . '_' . $screen->post_type;
			$hidden = get_user_meta( get_current_user_id(), $hidden_key, true );

			if ( empty( $hidden ) ) {
				// Hide the meta box for the post type.
				$this->hide_meta_box( $screen->post_type, $metabox_slug );
				update_user_meta( get_current_user_id(), $hidden_key, '1' );
			}
		}
	}
}

/**
 * Hides the meta box for a user and post type.
 *
 * @param  string $post_type     The post type.
 * @param  string $metabox_slug  The meta box slug.
 * @return void
 */
public function hide_meta_box( $post_type, $metabox_slug ) {

	$option = 'metaboxhidden_' . $post_type;

	$hidden = get_user_option( $option );
	$hidden = ! is_array( $hidden ) ? array() : $hidden;

	if ( is_array( $hidden ) ) {
		if ( ! in_array( $metabox_slug, $hidden ) ) {
			$hidden[] = $metabox_slug;
			update_user_option( get_current_user_id(), $option, $hidden, true );
		}
	}
}