ایجاد پلاگینی در متا باکس

//hook to add a meta box
add_action( 'add_meta_boxes', 'boj_mbe_create' );

function boj_mbe_create() {

	//create a custom meta box
	add_meta_box( 'boj-meta', 'My Custom Meta Box', 'boj_mbe_function', 'post', 'normal', 'high' );

}

function boj_mbe_function( $post ) {

	//retrieve the meta data values if they exist
	$boj_mbe_name = get_post_meta( $post->ID, '_boj_mbe_name', true );
	$boj_mbe_costume = get_post_meta( $post->ID, '_boj_mbe_costume', true );

	echo 'Please fill out the information below';
	?>
	<p>Name: <input type="text" name="boj_mbe_name" value="<?php echo esc_attr( $boj_mbe_name ); ?>" /></p>
    <p>Costume: 
    <select name="boj_mbe_costume">
        <option value="vampire" <?php selected( $boj_mbe_costume, 'vampire' ); ?>>Vampire</option>
        <option value="zombie" <?php selected( $boj_mbe_costume, 'zombie' ); ?>>Zombie</option>
        <option value="smurf" <?php selected( $boj_mbe_costume, 'smurf' ); ?>>Smurf</option>
    </select>
    </p>
	<?php
}

//hook to save the meta box data
add_action( 'save_post', 'boj_mbe_save_meta' );

function boj_mbe_save_meta( $post_id ) {

	//verify the meta data is set
	if ( isset( $_POST['boj_mbe_name'] ) ) {
	
		//save the meta data
		update_post_meta( $post_id, '_boj_mbe_name', strip_tags( $_POST['boj_mbe_name'] ) );
		update_post_meta( $post_id, '_boj_mbe_costume', strip_tags( $_POST['boj_mbe_costume'] ) );
	
	}

}