# Time Subsystem ChangeLog

## cl.time.1 API Error Change

Errors thrown by timer APIs of the time subsystem: **202** (non-system application) and **401** (invalid parameters).

**Change Impacts**

The API change is forward compatible. Applications developed based on earlier versions can still use the APIs, and corresponding error handling is added. The original functions are not affected.

**Key API/Component Changes**

Before change:
  - The API throws an error message without an error code.

After change:
  - The API throws an error message with an error code. Error code **202** indicates that the application is not a system application, and error code **401** indicates that the parameters are invalid.

    | Module           | Class       | Method/Attribute/Enumeration/Constant                                         | Change Type|
    | ----------------- | ----------- | ------------------------------------------------------------ | -------- |
    | @ohos.systemTimer | systemTimer | function createTimer(options: TimerOptions, callback: AsyncCallback\<number>): void | Changed    |
    | @ohos.systemTimer | systemTimer | function createTimer(options: TimerOptions): Promise\<number> | Changed    |
    | @ohos.systemTimer | systemTimer | function startTimer(timer: number, triggerTime: number, callback: AsyncCallback\<void>): void | Changed    |
    | @ohos.systemTimer | systemTimer | function startTimer(timer: number, triggerTime: number): Promise\<void> | Changed    |
    | @ohos.systemTimer | systemTimer | function stopTimer(timer: number, callback: AsyncCallback\<void>): void | Changed    |
    | @ohos.systemTimer | systemTimer | function stopTimer(timer: number): Promise\<void>            | Changed    |
    | @ohos.systemTimer | systemTimer | function destroyTimer(timer: number, callback: AsyncCallback\<void>): void | Changed    |
    | @ohos.systemTimer | systemTimer | function destroyTimer(timer: number): Promise\<void>         | Changed    |


**Adaptation Guide**

Refer to the code below to capture errors when **systemTimer** APIs are called in applications.

createTimer callback mode:

**Example**

```js
export default {
  systemTimer () {
    let options = {
      type: systemTimer.TIMER_TYPE_REALTIME,
      repeat: false
    };
    try {
      systemTimer.createTimer(options, (error, timerId) => {
        if (error) {
          // Capture the permission denial error.
          console.info(`Failed to create timer. message: ${error.message}, code: ${error.code}`);
        }
        console.info(`Succeeded in creating timer. timerId: ${timerId}`);
      });
    } catch(e) {
      // Capture the parameter verification error.
      console.info(`Failed to create timer. message: ${e.message}, code: ${e.code}`);
    }
  }
}
```

createTimer promise mode:

**Example**

```js
export default {
  systemTimer () {
    let options = {
      type: systemTimer.TIMER_TYPE_REALTIME,
      repeat: false
    };
    try {
      systemTimer.createTimer(options).then((timerId) => {
        console.info(`Succeeded in creating timer. timerId: ${timerId}`);
      }).catch((error) => {
        // Capture the permission denial error.
        console.info(`Failed to create timer. message: ${error.message}, code: ${error.code}`);
      });
    } catch(e) {
      // Capture the parameter verification error.
      console.info(`Failed to create timer. message: ${e.message}, code: ${e.code}`);
    }
  }
}
```

startTimer callback mode:

**Example**

```js
export default {
  async systemTimer () {
    let options = {
      type: systemTimer.TIMER_TYPE_REALTIME,
      repeat:false
    }
    let timerId = await systemTimer.createTimer(options);
    let triggerTime = new Date().getTime();
    triggerTime += 3000;
    try {
      systemTimer.startTimer(timerId, triggerTime, (error) => {
        if (error) {
          // Capture the permission denial error.
          console.error(`Failed to start timer. message: ${error.message}, code: ${error.code}`);
        }
        });
    } catch (e) {
      // Capture the parameter verification error.
      console.info(`Failed to start timer. message: ${e.message}, code: ${e.code}`);
    }
  }
}
```

startTimer promise mode:

**Example**

```js
export default {
  async systemTimer (){
    let options = {
      type: systemTimer.TIMER_TYPE_REALTIME,
      repeat:false
    }
    let timerId = await systemTimer.createTimer(options);
    let triggerTime = new Date().getTime();
    triggerTime += 3000;
    try {
      systemTimer.startTimer(timerId, triggerTime).then((data) => {
        console.log(`Succeeded in startting timer. Data:` + data);
      }).catch((error) => {
        // Capture the permission denial error.
        console.info(`Failed to start timer. message: ${error.message}, code: ${error.code}`);
      });
    } catch (e) {
      // Capture the parameter verification error.
      console.info(`Failed to start timer. message: ${e.message}, code: ${e.code}`);
    }
  }
}
```

stopTimer callback mode:

**Example**

```js
export default {
  async systemTimer () {
    let options = {
      type: systemTimer.TIMER_TYPE_REALTIME,
      repeat:false
    }
    let timerId = await systemTimer.createTimer(options);
    let triggerTime = new Date().getTime();
    triggerTime += 3000;
    systemTimer.startTimer(timerId, triggerTime);
    try {
      systemTimer.stopTimer(timerId, triggerTime, (error) => {
        if (error) {
          // Capture the permission denial error.
          console.error(`Failed to stop timer. message: ${error.message}, code: ${error.code}`);
        }
        });
    } catch (e) {
      // Capture the parameter verification error.
      console.info(`Failed to stop timer. message: ${e.message}, code: ${e.code}`);
    }
  }
}git 
```

stopTimer promise mode:

**Example**

```js
export default {
  async systemTimer (){
    let options = {
      type: systemTimer.TIMER_TYPE_REALTIME,
      repeat:false
    }
    let timerId = await systemTimer.createTimer(options);
    let triggerTime = new Date().getTime();
    triggerTime += 3000;
    systemTimer.startTimer(timerId, triggerTime);
    try {
      systemTimer.stopTimer(timerId, triggerTime).then((data) => {
        console.log(`Succeeded in stop timer. Data:` + data);
      }).catch((error) => {
        // Capture the permission denial error.
        console.info(`Failed to stop timer. message: ${error.message}, code: ${error.code}`);
      });
    } catch (e) {
      // Capture the parameter verification error.
      console.info(`Failed to stop timer. message: ${e.message}, code: ${e.code}`);
    }
  }
}
```

destroyTimer callback mode:

**Example**

```js
export default {
  async systemTimer () {
    let options = {
      type: systemTimer.TIMER_TYPE_REALTIME,
      repeat:false
    }
    let timerId = await systemTimer.createTimer(options);
    let triggerTime = new Date().getTime();
    triggerTime += 3000;
    systemTimer.startTimer(timerId, triggerTime);
    systemTimer.stopTimer(timerId);
    try {
      systemTimer.destroyTimer(timerId, triggerTime, (error) => {
        if (error) {
          // Capture the permission denial error.
          console.error(`Failed to destroy timer. message: ${error.message}, code: ${error.code}`);
        }
        });
    } catch (e) {
      // Capture the parameter verification error.
      console.info(`Failed to destroy timer. message: ${e.message}, code: ${e.code}`);
    }
  }
}
```

destroyTimer promise mode:

**Example**

```js
export default {
  async systemTimer (){
    let options = {
      type: systemTimer.TIMER_TYPE_REALTIME,
      repeat:false
    }
    let timerId = await systemTimer.createTimer(options);
    let triggerTime = new Date().getTime();
    triggerTime += 3000;
    systemTimer.startTimer(timerId, triggerTime);
    systemTimer.stopTimer(timerId);
    try {
      systemTimer.destroyTimer(timerId, triggerTime).then((data) => {
        console.log(`Succeeded in destroy timer. Data:` + data);
      }).catch((error) => {
        // Capture the permission denial error.
        console.info(`Failed to destroy timer. message: ${error.message}, code: ${error.code}`);
      });
    } catch (e) {
      // Capture the parameter verification error.
      console.info(`Failed to destroy timer. message: ${e.message}, code: ${e.code}`);
    }
  }
}
```

## cl.time.2 API Error Change

Errors thrown by timer APIs of the time subsystem: **201** (permission denied), **202** (non-system application), and **401** (invalid parameters).

**Change Impacts**

Applications developed based on earlier versions can still use the APIs. When new APIs are used, errors must be captured and processed.

**Key API/Component Changes**

Before change:
  - The API throws an error message with error code **-1**.

After change:
  - The API throws an error message with an error code. Error code **201** indicates that the permission is denied, error code **202** indicates that the application is not a system application, and error code **401** indicates that the parameters are invalid.

Deprecated APIs can be replaced with new ones with same names.

| Original API          | New API              |
| ---------------- | -------------------- |
| @ohos.systemTime | @ohos.systemDateTime |

**Adaptation Guide**

Refer to the code below to capture errors when **systemTime** APIs are called in applications. In the examples, the **setTime** API is invoked.

In callback mode:

**Example**

```js
import systemDateTime from @ohos.systemDateTime
// Set the system time to 2021-01-20 02:36:25.
let time = 1611081385000;
try {
  systemDateTime.setTime(time, (error) => {
    // Capture permission denial and non-system-application errors.
    if (error) {
      console.info(`Failed to setting time. message: ${error.message}, code: ${error.code}`);
      return;
    }
    console.info(`Succeeded in setting time.`);
  })
} catch(e) {
  // Capture the parameter verification error.
  console.info(`Failed to set time. message: ${e.message}, code: ${e.code}`);
}
```

In promise mode:

**Example**

```js
import systemDateTime from @ohos.systemDateTime
// Set the system time to 2021-01-20 02:36:25.
let time = 1611081385000;
try {
  systemDateTime.setTime(time).then(() => {
    console.info(`Succeeded in setting time.`);
  }).catch((error) => {
    // Capture permission denial and non-system-application errors.
    console.info(`Failed to setting time. message: ${error.message}, code: ${error.code}`);
  });
} catch(e) {
   // Capture the parameter verification error.
  console.info(`Failed to set time. message: ${e.message}, code: ${e.code}`);
}
```