# MissionCallback

The **MissionCallback** module defines the callbacks invoked after synchronization starts. These callbacks can be used as input parameters in [registerMissionListener](js-apis-distributedMissionManager.md#distributedmissionmanagerregistermissionlistener).

**System capability**: SystemCapability.Ability.AbilityRuntime.Mission

| Name                                                | Template    | Readable| Writable| Description                              |
| ---------------------------------------------------- | -------- | ---- | ---- | ---------------------------------- |
| notifyMissionsChanged(deviceId: string)              | function | Yes  | No  | Callback used to notify the mission change event and return the device ID.        |
| notifySnapshot(deviceId: string, mission: number)    | function | Yes  | No  | Callback used to notify the snapshot change event and return the device ID and mission ID.  |
| notifyNetDisconnect(deviceId: string, state: number) | function | Yes  | No  | Callback used to notify the disconnection event and return the device ID and network status.|

**Example**
```ts
import distributedMissionManager from '@ohos.distributedMissionManager';

let missionDeviceInfo = {
    deviceId: '123456'
};
let missionCallback = {
    notifyMissionsChanged: function (deviceId) {
        console.log('notifyMissionsChanged deviceId: ' + JSON.stringify(deviceId));
    },
    notifySnapshot: function (deviceId, mission) {
        console.log('notifySnapshot deviceId: ' + JSON.stringify(deviceId));
        console.log('notifySnapshot mission: ' + JSON.stringify(mission));
    },
    notifyNetDisconnect: function (deviceId, state) {
        console.log('notifyNetDisconnect deviceId: ' + JSON.stringify(deviceId));
        console.log('notifyNetDisconnect state: ' + JSON.stringify(state));
    }
};
distributedMissionManager.registerMissionListener(missionDeviceInfo, missionCallback);
```