Settings API (category)
| add_settings_error() | Registers a message for option validation to later display this message to the user. Usually, such a message is a data validation error. |
| add_settings_field() | Creates an options field for the specified section (specified settings block). |
| add_settings_section() | Creates a new block (section) in which the settings fields are displayed. That is, options are then added to this block using add_settings_field(). |
| do_settings_fields() | Displays on the screen the option fields related to the specified section. |
| do_settings_sections() | Outputs to the screen all option blocks related to the specified settings page in the admin panel. |
| get_settings_errors() | Retrieves messages registered by the function add_settings_error(). |
| register_setting() | Registers a new option and a callback function to handle the option value when it is saved to the database. |
| settings_errors() | Displays on the screen messages (notices and errors) registered by the function add_settings_error(). |
| settings_fields() | Outputs hidden form fields on the settings page (option_page, _wpnonce, ...). |
| unregister_setting() | Allows unregistering previously registered settings (options). Most often used with a plugin deactivation function: register_deactivation_hook(). |