Source: includes/admin/class-notices.php

<?php
namespace jb\admin;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

if ( ! class_exists( 'jb\admin\Notices' ) ) {

	/**
	 * Class Notices
	 *
	 * @package jb\admin
	 */
	class Notices {

		/**
		 * Notices list
		 *
		 * @var array
		 *
		 * @since 1.0
		 */
		public $list = array();

		/**
		 * Notices constructor.
		 */
		public function __construct() {
			add_action( 'admin_init', array( &$this, 'create_list' ) );
			add_action( 'admin_notices', array( &$this, 'render' ), 1 );
		}

		/**
		 * Initialize all admin notices
		 *
		 * @since 1.0
		 */
		public function create_list() {
			$this->install_predefined_page_notice();
			$this->show_update_messages();
			$this->template_version();
			/**
			 * Fires when admin notices list is generated.
			 * Note: It's an internal hook that you could use for adding admin notices to JobBoardWP admin notices list.
			 *
			 * @since 1.1.0
			 * @hook jb_admin_create_notices
			 */
			do_action( 'jb_admin_create_notices' );
		}

		/**
		 * Render all admin notices
		 *
		 * @since 1.0
		 */
		public function render() {
			if ( ! current_user_can( 'manage_options' ) ) {
				return;
			}

			$admin_notices = $this->get_admin_notices();

			$hidden = JB()->options()->get( 'hidden_admin_notices', array() );

			uasort( $admin_notices, array( &$this, 'notice_priority_sort' ) );

			foreach ( $admin_notices as $key => $admin_notice ) {
				if ( empty( $hidden ) || ! in_array( $key, $hidden, true ) ) {
					$this->display( $key );
				}
			}

			/**
			 * Fires after render and display all admin notices.
			 *
			 * @since 1.1.0
			 * @hook jb_admin_after_main_notices
			 */
			do_action( 'jb_admin_after_main_notices' );
		}

		/**
		 * Getting all admin notices
		 *
		 * @return array
		 *
		 * @since 1.0
		 */
		public function get_admin_notices() {
			return $this->list;
		}

		/**
		 * Set admin notices variable
		 *
		 * @param array $admin_notices
		 *
		 * @since 1.0
		 */
		public function set_admin_notices( $admin_notices ) {
			$this->list = $admin_notices;
		}

		/**
		 * Sorting notices in predefined priority
		 *
		 * @param array $a
		 * @param array $b
		 *
		 * @return int
		 *
		 * @since 1.0
		 */
		public function notice_priority_sort( $a, $b ) {
			if ( $a['priority'] === $b['priority'] ) {
				return 0;
			}
			return ( $a['priority'] < $b['priority'] ) ? -1 : 1;
		}

		/**
		 * Add notice to JB notices array
		 *
		 * @param string $key
		 * @param array $data
		 * @param int $priority
		 *
		 * @since 1.0
		 */
		public function add( $key, $data, $priority = 10 ) {
			$admin_notices = $this->get_admin_notices();

			if ( empty( $admin_notices[ $key ] ) ) {
				$admin_notices[ $key ] = array_merge( $data, array( 'priority' => $priority ) );
				$this->set_admin_notices( $admin_notices );
			}
		}

		/**
		 * Remove notice from JB notices array
		 *
		 * @param string $key
		 *
		 * @since 1.0
		 */
		public function remove_notice( $key ) {
			$admin_notices = $this->get_admin_notices();

			if ( ! empty( $admin_notices[ $key ] ) ) {
				unset( $admin_notices[ $key ] );
				$this->set_admin_notices( $admin_notices );
			}
		}

		/**
		 * Display single admin notice
		 *
		 * @param string $key
		 * @param bool   $display
		 *
		 * @return string
		 *
		 * @since 1.0
		 */
		public function display( $key, $display = true ) {
			$admin_notices = $this->get_admin_notices();

			if ( empty( $admin_notices[ $key ] ) ) {
				return '';
			}

			$notice_data = $admin_notices[ $key ];

			$class = ! empty( $notice_data['class'] ) ? $notice_data['class'] : 'updated';
			if ( ! empty( $admin_notices[ $key ]['dismissible'] ) ) {
				$class .= ' is-dismissible';
			}

			$message = ! empty( $notice_data['message'] ) ? $notice_data['message'] : '';

			ob_start();
			?>

			<div class="jb-admin-notice notice <?php echo esc_attr( $class ); ?>" data-key="<?php echo esc_attr( $key ); ?>">
				<?php echo wp_kses( $message, JB()->get_allowed_html( 'admin_notice' ) ); ?>
			</div>

			<?php
			if ( $display ) {
				ob_end_flush();
				return '';
			}

			return ob_get_clean();
		}

		/**
		 * Dismiss notices by key
		 *
		 * @param string $key
		 *
		 * @since 1.0
		 */
		public function dismiss( $key ) {
			$hidden_notices   = JB()->options()->get( 'hidden_admin_notices', array() );
			$hidden_notices[] = $key;
			JB()->options()->update( 'hidden_admin_notices', array_unique( $hidden_notices ) );
		}

		/**
		 * Regarding page setup
		 *
		 * @since 1.0
		 */
		public function install_predefined_page_notice() {
			if ( ! current_user_can( 'manage_options' ) || JB()->common()->permalinks()->are_pages_installed() ) {
				return;
			}

			$page_titles = array();
			foreach ( JB()->config()->get( 'predefined_pages' ) as $array ) {
				$page_titles[] = $array['title'];
			}

			$create_pages_link = add_query_arg(
				array(
					'jb_adm_action' => 'install_predefined_pages',
					'nonce'         => wp_create_nonce( 'jb_install_predefined_pages' ),
				)
			);

			ob_start();
			?>

			<p>
				<?php
				printf(
					// translators: %1$s: plugin name, %2$s: list of pre-defined pages
					esc_html__( 'To add job board functionality to your website %1$s needs to create the following pages: %2$s.', 'jobboardwp' ),
					esc_html( JB_PLUGIN_NAME ),
					esc_html( implode( ', ', $page_titles ) )
				);
				?>
			</p>
			<p>
				<a href="<?php echo esc_attr( $create_pages_link ); ?>" class="button button-primary">
					<?php esc_html_e( 'Create Pages', 'jobboardwp' ); ?>
				</a>
				&nbsp;
				<a href="#" class="button-secondary jb_secondary_dismiss">
					<?php esc_html_e( 'No thanks', 'jobboardwp' ); ?>
				</a>
			</p>

			<?php
			$message = ob_get_clean();

			$this->add(
				'wrong_pages',
				array(
					'class'       => 'updated',
					'message'     => $message,
					'dismissible' => true,
				),
				20
			);
		}

		/**
		 * Notices
		 *
		 * @since 1.0
		 */
		public function show_update_messages() {
			if ( ! isset( $_REQUEST['update'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification
				return;
			}

			$update = sanitize_key( $_REQUEST['update'] ); // phpcs:ignore WordPress.Security.NonceVerification
			switch ( $update ) {
				case 'jb_settings_updated':
					$messages[0]['content'] = __( 'Settings updated successfully.', 'jobboardwp' );

					break;
			}

			if ( ! empty( $messages ) ) {
				foreach ( $messages as $message ) {
					$this->add(
						'actions',
						array(
							'class'   => 'updated',
							'message' => '<p>' . $message['content'] . '</p>',
						),
						20
					);
				}
			}
		}

		/**
		 * Check Templates Versions notice
		 */
		public function template_version() {
			if ( true === (bool) get_option( 'jb_override_templates_outdated' ) ) {
				$link = admin_url( 'admin.php?page=jb-settings&tab=override_templates' );
				ob_start();
				?>

				<p>
					<?php
					// translators: %s override templates page link.
					echo wp_kses( sprintf( __( 'Your templates are out of date. Please visit <a href="%s">override templates status page</a> and update templates.', 'jobboardwp' ), $link ), JB()->get_allowed_html( 'wp-admin' ) );
					?>
				</p>

				<?php
				$message = ob_get_clean();
				$this->add(
					'jb_override_templates_notice',
					array(
						'class'       => 'error',
						'message'     => $message,
						'dismissible' => false,
					),
					10
				);
			}
		}
	}
}