WordPress插件可在自定义文件夹中上传pdf文件

Question

我正在制作一个插件，它将在WordPress的“ UPLOADS”文件夹中的自定义文件夹中上传pdf文件，并将路径插入MySQL数据库中。我检查了Stack Overflow中的各种答复，但似乎对我没有用。插件将不会上传文件，也不会将其插入数据库中

/*********                   START OF                               ************
    ********** INSERTION OF DATA AND UPLOADING FILE IN CUSTOM DIRECTORY ***********/

    if($_POST['upload_pdf']) {
         global $wpdb;
         $table_name =$wpdb->prefix . 'pdf_file_registry';
         $tmpp_name = $_FILE['pdf_select']['tmp_name'];
            if($_FILES['pdf_select']['type'] == "application/pdf") {
                $uploadedfile = $_FILES['pdf_select'];

                add_filter( 'upload_dir', 'wpse_183245_upload_dir' );

                function wpse_183245_upload_dir( $dirs ) {
                    $dirs['subdir'] = '/pdf_upload_directory';
                    $dirs['path'] = $dirs['basedir'] . '/pdf_upload_directory';
                    $dirs['url'] = $dirs['baseurl'] . '/pdf_upload_directory';
                    return $dirs;
                }

                $movefile = wp_handle_upload($uploadedfile); 

                remove_filter( 'upload_dir', 'wpse_183245_upload_dir' );

                $pdf_file_name = $_FILE['pdf_select']['name'];
                $category_name = $_POST['category_name'];
                $pdf_title = $_POST['pdf_title'];
                $pdf_path = "test";

                 $success = $wpdb->insert("wp_pdf_file_registry", array(
                   "pdf_file_name" => $pdf_file_name,
                   "pdf_title" => $pdf_title,
                   "pdf_category" => $category_name,
                   "pdf_path" => $pdf_path,
                ));
                 if($success) {
                 echo ' Inserted successfully';
                      } else {
                   echo 'not';
                   }

            }
        }

    /*********                   END OF                               ************
    ********** INSERTION OF DATA AND UPLOADING FILE IN CUSTOM DIRECTORY ***********/

我在哪里弄错了？