WordPress：使用帖子ID和帖子标题作为上传图像的文件名

Question

I am trying to add the post ID and the post title to all uploaded images in my WordPress posts.

I have already found a function, which renames my images like a charm, but I cannot get the post id and post title. What am I doing wrong?

function new_filename($filename, $filename_raw) {

    global $post;
    $post_id = $post->ID; 
    $post_slug = $post->post_name;

    $info = pathinfo($filename);
    $ext  = empty($info['extension']) ? '' : '.' . $info['extension'];
    $new = $post_id . $post_slug . $ext;

    if( $new != $filename_raw ) {
        $new = sanitize_file_name( $new );
    }

    return $new;

}
add_filter('sanitize_file_name', 'new_filename', 10, 2);

Thank you.

Answer 1

Your images are uploaded in /wp-admin and in the admin area it is unfortunatly not always easy to get the post ID and the post title.

First of all you have to check if there even is a post ID and title. Because if somebody upload an image within the media library itself, there simple is no post title or id.

If somebody is uploading an image to a page / post / custom post type edit page instead, there should be a post ID.

Try:

 $post_id = $_GET['post'];

In general I would recommend the following procedure:

function new_filename($filename, $filename_raw) {

    $post = admin_find_current_post();

    if($post) {
         // proceed as you have proposed
     } else {
          return $filename;
     }

}
add_filter('sanitize_file_name', 'new_filename', 10, 2);


function admin_find_current_post() {
    if(isset($_GET['post']) && intval($_GET['post']) > 0 ) {
         return get_post($_GET['post']);
    }

    global $post;
    if($post) {
        return $post;
    }

    // and maybe more possibilities?

}

Therefore the rest of the challange for you is to complete this function and check if it can be improved further ;-)