# @ohos.data.cloudData (Device-Cloud Service)

The **cloudData** module provides APIs for implementing device-cloud synergy and device-cloud sharing, and setting the device-cloud sync strategy.

Device-cloud synergy enables sync of the structured data (in RDB stores) between devices and the cloud. The cloud serves as a data hub to implement data backup in the cloud and data consistency between the devices with the same account.
This module also provides the capability of setting the device-cloud sync strategy.

> **NOTE**
>
> The initial APIs of this module are supported since API version 12. Newly added APIs will be marked with a superscript to indicate their earliest API version.

## Modules to Import

```ts
import { cloudData } from '@kit.ArkData';
```

## StrategyType

Enumerates the types of the cloud-device sync strategy.

**System capability**: SystemCapability.DistributedDataManager.CloudSync.Client

| Name     | Value | Description       |
| --------- |---|-----------|
| NETWORK | 0 | Sync over the network. |

## NetWorkStrategy

Enumerates the network sync options.

**System capability**: SystemCapability.DistributedDataManager.CloudSync.Client

| Name     | Value | Description       |
| --------- |---|-----------|
| WIFI | 1 | Sync over Wi-Fi. |
| CELLULAR | 2 | Sync over the cellular network.  |

## cloudData.setCloudStrategy
setCloudStrategy(strategy: StrategyType, param?: Array<commonType.ValueType>): Promise<void>

<!--RP1-->
Sets the device-cloud sync strategy for the application. If no strategy is set, the global strategy set by [setGlobalCloudStrategy<sup>12+</sup>](js-apis-data-cloudData-sys.md#setglobalcloudstrategy12) is used. If the global strategy is not set, the application data is synced over Wi-Fi and the cellular network by default. This API uses a promise to return the result.<!--RP1End-->

**System capability**: SystemCapability.DistributedDataManager.CloudSync.Client

| Name    | Type                                                                         | Mandatory | Description                            |
| ---------- |-----------------------------------------------------------------------------| ---- | -------------------------------- |
| strategy  | [StrategyType](#strategytype)                                               | Yes  | Type of the strategy to set.            |
| param | Array&lt;[commonType.ValueType](js-apis-data-commonType.md#valuetype)&gt; | No  | Strategy parameters to set. If this parameter is not specified, all the configuration is canceled. |

**Return value**

| Type               | Description                     |
| ------------------- | ------------------------- |
| Promise&lt;void&gt; | Promise that returns no value. |

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md).

| **ID** | **Error Message**                                                |
|-----------| ------------------------------------------------------------ |
| 401       | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |
| 801       | Capability not supported.|

**Example**

```ts
import { BusinessError } from '@kit.BasicServicesKit';

// Sync data over Wi-Fi only.
cloudData.setCloudStrategy(cloudData.StrategyType.NETWORK, [cloudData.NetWorkStrategy.WIFI]).then(() => {
    console.info('Succeeded in setting the cloud strategy');
}).catch((err: BusinessError) => {
    console.error(`Failed to set cloud strategy. Code: ${err.code}, message: ${err.message}`);
});

```
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