最近我们在重构WordPress采集插件WP-JPost，这里记录一下当我们激活插件时在面板中添加通知的方法。

使用场景

我们插件使用register_post_type方法来构建了自定义文章（wordpress使用register_post_type 函数创建自定义文章类型）后出现了404的错误。这里我们使用添加通知的方法来告知用户必须设置一下【固定链接】（WordPress 固定链接设置）才能正常使用。下面我们记录一下具体的实现方法。

添加通知方法

可以通过admin_notices的add_action来实现。

		add_action( 'admin_notices', array( $this, 'jpost_notice' ) );

实现方法函数

做好输出工作即可。

	public function jpost_notice(){
		if( get_post_type() == $this->post_type )
			printf('<div class="jads"></div>');
		/* Check transient, if available display notice */
		if (! get_option('permalink_structure') ){
			printf('<div class="updated notice notice-warning is-dismissible">');
			printf('<p>%s</p>', __( 'WP-JPost need Navigate to [ <strong>Dashboard</strong> ] -> [ <strong>Settings</strong> ] -> [ <strong>Permalink</strong> ] page -> click [ <strong>Save</strong> ] button to flush rewrite rules. [ <a href="https://www.jiloc.com/44235.html">?</a> ]') );
			printf('</div>');
			/* Delete transient, only display this notice once. */
			// delete_transient( 'jpost-notice' );
		}
	}

激活插件事件

当没有设置固定链接的时候输出 jpost-notice 的通知。

	static function active() {
		if (! get_option('permalink_structure') )
			set_transient( 'jpost-notice', true );
		flush_rewrite_rules();
	}

全部代码

//register activation function
register_activation_hook( __FILE__, array( 'WP_JPost', 'active') );
//register deactivation function
register_deactivation_hook( __FILE__ , array( 'WP_JPost', 'deactive') );
class WP_JPost {
	protected $jpost_readme = 'https://www.jiloc.com/wp-jpost';
	protected $post_type = 'wp-jpost';
	protected $rewrite_slug = 'jpost';
	/**
	 * Constructor.
	 */
	public function __construct() {
                add_action( 'plugins_loaded', array( $this, 'load_textdomain' ) );
		add_action( 'init', array( $this, 'register_post_type' ) );
		// add_filter( 'post_type_link', array($this , 'custom_link' ), 1, 3);
		add_filter( 'query_vars', array( $this, 'jpost_query_vars') );
		add_filter( 'post_updated_messages', array( $this, 'updated_message' ) );
		// add_action( 'admin_init',array($this,'register_setting_page'));
		add_action( 'admin_menu', array( $this, 'add_meta_box' ) );
		add_action( 'save_post', array( $this, 'meta_box_save' ), 1, 2 );
		add_action( 'manage_wp-jpost_posts_custom_column', array( $this, 'columns_data' ) );
		add_filter( 'manage_wp-jpost_posts_columns', array( $this, 'columns_filter' ) );
		add_action( 'template_redirect', array( $this, 'jpost_grab' ) );
		add_action( 'admin_notices', array( $this, 'jpost_notice' ) );
	}
	
	public function custom_link( $permalink, $post ){
		if ( $post->post_type == $this->post_type ){
			return $permalink . ( strpos( $permalink ,'?' ) !== false ? '&' : '?') . 'jpage='.get_post_meta( get_the_ID(), '_jpost_task_list_max_page', true ) . '&debug=1';
		} else {
			return $permalink;
		}
	}

	public function jpost_notice(){
		if( get_post_type() == $this->post_type )
			printf('<div class="jads"></div>');
		/* Check transient, if available display notice */
		if (! get_option('permalink_structure') ){
			printf('<div class="updated notice notice-warning is-dismissible">');
			printf('<p>%s</p>', __( 'WP-JPost need Navigate to [ <strong>Dashboard</strong> ] -> [ <strong>Settings</strong> ] -> [ <strong>Permalink</strong> ] page -> click [ <strong>Save</strong> ] button to flush rewrite rules. [ <a href="https://www.jiloc.com/44235.html">?</a> ]') );
			printf('</div>');
			/* Delete transient, only display this notice once. */
			// delete_transient( 'jpost-notice' );
		}
	}

	static function active() {
		if (! get_option('permalink_structure') )
			set_transient( 'jpost-notice', true );
		flush_rewrite_rules();
	}
}