| IFolder | This interface provides elementary getter and setter methods for folder objects. All folder types (Folder, Collection, Gallery, . |
| IFolderActions | This interface provides elementary action methods for folder objects. All folder types (Folder, Collection, Gallery, . |
| IFolderContent | This interface provides elementary action methods for folder content. All folder types (Folder, Collection, Gallery, . |
| IMetadata | Metadata content of a folder. The metadata can be changed in the arrow-down icon in the folders sidebar toolbar. To handle metadata for folders you can use the add_media_folder_meta function. |
| IStructure | Structure implementation for Real Media Library. It handles all SQL query which reads all folders from the database and "collects" it into one tree. You can modify the structure queries by RML/Tree* filters and extending the MatthiasWeb\RealMediaLibrary\attachment\Structure class (implements IStructure). |
| IUserSettings | Metadata content for the general user settings. The metadata can be changed in the cog icon in the folders sidebar toolbar. To handle metadata for general user settings you can use the default WordPress add_user_meta function. |