You can set your application to call the **ReminderRequest** class to create scheduled reminders for countdown timers, calendar events, and alarm clocks. When the created reminders are published, the timing and pop-up notification functions of your application will be taken over by the reminder agent in the background, even when your application is frozen or exits.
## Available APIs
**reminderAgent** encapsulates the methods for publishing and canceling reminders.
| function publishReminder(reminderReq: ReminderRequest, callback: AsyncCallback\<number>): void;<br>function publishReminder(reminderReq: ReminderRequest): Promise\<number>; | Publishes a scheduled reminder.<br>The maximum number of valid notifications (excluding expired ones that will not pop up again) is 30 for one application and 2000 for the entire system. |
| function cancelReminder(reminderId: number, callback: AsyncCallback\<void>): void;<br/>function cancelReminder(reminderId: number): Promise\<void>; | Cancels a specified reminder. (The value of **reminderId** is obtained from the return value of **publishReminder**.) |
| function getValidReminders(callback: AsyncCallback<Array\<ReminderRequest>>): void;<br/>function getValidReminders(): Promise<Array\<ReminderRequest>>; | Obtains all valid reminders set by the current application. |
| function cancelAllReminders(callback: AsyncCallback\<void>): void;<br/>function cancelAllReminders(): Promise\<void>; | Cancels all reminders set by the current application. |
| function addNotificationSlot(slot: NotificationSlot, callback: AsyncCallback\<void>): void;<br/>function addNotificationSlot(slot: NotificationSlot): Promise<void>; | Registers a NotificationSlot instance to be used by the reminder. |
| function removeNotificationSlot(slotType: notification.SlotType, callback: AsyncCallback\<void>): void;function removeNotificationSlot(slotType: notification.SlotType): Promise\<void>; | Removes a NotificationSlot instance of a specified type. |
| Name| Description|
| -------- | -------- |
| function publishReminder(reminderReq: ReminderRequest, callback: AsyncCallback<number>): void;<br>function publishReminder(reminderReq: ReminderRequest): Promise<number>; | Publishes a scheduled reminder.<br>The maximum number of valid notifications (excluding expired ones that will not pop up again) is 30 for one application and 2000 for the entire system. |
| function cancelReminder(reminderId: number, callback: AsyncCallback<void>): void;<br>function cancelReminder(reminderId: number): Promise<void>; | Cancels a specified reminder. (The value of **reminderId** is obtained from the return value of **publishReminder**.)|
| function getValidReminders(callback: AsyncCallback<Array<ReminderRequest>>): void;<br>function getValidReminders(): Promise<Array<ReminderRequest>>; | Obtains all valid reminders set by the current application.|
| function cancelAllReminders(callback: AsyncCallback<void>): void;<br>function cancelAllReminders(): Promise<void>; | Cancels all reminders set by the current application.|
| function addNotificationSlot(slot: NotificationSlot, callback: AsyncCallback<void>): void;<br>function addNotificationSlot(slot: NotificationSlot): Promise<void>; | Registers a **NotificationSlot** instance to be used by the reminder. |
| function removeNotificationSlot(slotType: notification.SlotType, callback: AsyncCallback<void>): void;<br>function removeNotificationSlot(slotType: notification.SlotType): Promise<void>; | Removes a **NotificationSlot** instance of a specified type. |
**ActionButtonType** enumerates types of buttons displayed in a reminder notification.
| ACTION_BUTTON_TYPE_CLOSE | Close button, which can be tapped to stop the reminder alert tone, close the reminder notification, and cancel the reminder snoozing. |
| Name| Description|
| -------- | -------- |
| ACTION_BUTTON_TYPE_CLOSE | Close button, which can stop the reminder alert tone, close the reminder notification, and cancel the reminder snoozing.|
| ACTION_BUTTON_TYPE_SNOOZE | Snooze button, which can snooze the reminder.|
**ReminderType** enumerates the reminder types.
**Table 3** ReminderType enumeration
**Table 3** ReminderType enums
| Name | Description |
| ---------------------- | ------------------- |
| REMINDER_TYPE_TIMER | Countdown reminder. |
| REMINDER_TYPE_CALENDAR | Calendar reminder.|
| REMINDER_TYPE_ALARM | Alarm reminder. |
| Name| Description|
| -------- | -------- |
| REMINDER_TYPE_TIMER | Countdown reminder.|
| REMINDER_TYPE_CALENDAR | Calendar reminder.|
| REMINDER_TYPE_ALARM | Alarm reminder.|
**ActionButton** defines a button displayed in the reminder notification.
| pkgName | string | Yes | Name of the package redirected to when the reminder notification is clicked. |
| abilityName | string | Yes | Name of the ability redirected to when the reminder notification is clicked. |
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| pkgName | string | Yes| Name of the package redirected to when the reminder notification is clicked.|
| abilityName | string | Yes| Name of the ability redirected to when the reminder notification is clicked.|
**MaxScreenWantAgent** sets the name of the target package and ability to start automatically when the reminder arrives and the device is not in use. If the device is in use, a notification will be displayed.
| reminderType | ReminderType | Yes | Type of the reminder. |
| actionButton | [ActionButton?, ActionButton?] | No | Action button displayed in the reminder notification. |
| wantAgent | WantAgent | No | Information about the ability that is redirected to when the notification is clicked. |
| maxScreenWantAgent | MaxScreenWantAgent | No | Information about the ability that is automatically started when the reminder arrives. If the device is in use, a notification will be displayed. |
| ringDuration | number | No | Ring duration. |
| snoozeTimes | number | No | Number of reminder snooze times. |
| timeInterval | number | No | Reminder snooze interval. |
| title | string | No | Reminder title. |
| content | string | No | Reminder content. |
| expiredContent | string | No | Extended content to be displayed when the reminder expires. |
| snoozeContent | string | No | Extended content to be displayed when the reminder is snoozing. |
| notificationId | number | No | Notification ID used by the reminder. For details, see the API reference of the **NotificationRequest.setNotificationId(int id)** method. |
| slotType | SlotType | No | Type of the slot used by the reminder. |
**Table 7** ReminderRequest
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| reminderType | ReminderType | Yes| Type of the reminder.|
| actionButton | [ActionButton?,ActionButton?] | No| Action button displayed in the reminder notification.|
| wantAgent | WantAgent | No| Information about the ability that is redirected to when the notification is clicked.|
| maxScreenWantAgent | MaxScreenWantAgent | No| Information about the ability that is automatically started when the reminder arrives. If the device is in use, a notification will be displayed.|
| ringDuration | number | No| Ring duration.|
| snoozeTimes | number | No| Number of reminder snooze times.|
| timeInterval | number | No| Reminder snooze interval.|
| title | string | No| Reminder title.|
| content | string | No| Reminder content.|
| expiredContent | string | No| Extended content to be displayed when the reminder expires.|
| snoozeContent | string | No| Extended content to be displayed when the reminder is snoozing.|
| notificationId | number | No| Notification ID used by the reminder. For details, see **NotificationRequest::SetNotificationId(int32_t id)**.|
| slotType | SlotType | No| Type of the slot used by the reminder. |
**ReminderRequestCalendar** extends **ReminderRequest** and defines a reminder for a calendar event.
For the application to run properly, if both **repeatMonths** and **repeatDays** are not specified, the earliest reminder time must be later than the current time.