1# DataAbility Switching 2 3 4The DataAbility component in the FA model corresponds to the DataShareExtensionAbility component in the stage model. 5 6 7The DataShareExtensionAbility class provides system APIs. Only system applications can create DataShareExtensionAbility instances. Therefore, DataAbility switching adopts different policies for system applications and third-party applications. 8 9 10## Switching a DataAbility of a System Application 11 12The procedure for switching a DataAbility of a system application is similar to the procedure of PageAbility switching. 13 141. Create a DataShareExtensionAbility in the stage model. 15 162. Migrate the DataAbility code to the DataShareExtensionAbility. 17 18 The table below describes the lifecycle comparison of the DataAbility and DataShareExtensionAbility. 19 20 | DataAbility| DataShareExtensionAbility| Comparison Description| 21 | -------- | -------- | -------- | 22 | onInitialized?(info: AbilityInfo): void | onCreate?(want: Want, callback: AsyncCallback<void>): void<br> | The two methods have the same invoking time but different input parameters. In the stage model, the **want** parameter is added so that you can obtain parameters during creation.| 23 | update?(uri: string, valueBucket: rdb.ValuesBucket, predicates: dataAbility.DataAbilityPredicates, callback: AsyncCallback<number>): void | update?(uri: string, predicates: dataSharePredicates.DataSharePredicates, value: ValuesBucket, callback: AsyncCallback<number>): void | The two methods have the same meaning and invoking time, but slightly different parameter sequence and parameter type. A simple reconstruction is required.| 24 | query?(uri: string, columns: Array<string>, predicates: dataAbility.DataAbilityPredicates, callback: AsyncCallback<ResultSet>): void | query?(uri: string, predicates: dataSharePredicates.DataSharePredicates, columns: Array<string>, callback: AsyncCallback<Object>): void;| The two methods have the same meaning and invoking time, but slightly different parameter sequence and parameter type. A simple reconstruction is required.| 25 | delete?(uri: string, predicates: dataAbility.DataAbilityPredicates, callback: AsyncCallback<number>): void | delete?(uri: string, predicates: dataSharePredicates.DataSharePredicates, callback: AsyncCallback<number>):| The two methods have the same meaning and invoking time, but slightly different parameter type. A simple reconstruction is required.| 26 | normalizeUri?(uri: string, callback: AsyncCallback<string>): void | normalizeUri?(uri: string, callback: AsyncCallback<string>): void| The two methods have the same meaning, invoking time, and parameters.| 27 | batchInsert?(uri: string, valueBuckets: Array<rdb.ValuesBucket>, callback: AsyncCallback<number>): void | batchInsert?(uri: string, values: Array<ValuesBucket>, callback: AsyncCallback<number>): void| The two methods have the same meaning and invoking time, but slightly different parameter type. A simple reconstruction is required.| 28 | denormalizeUri?(uri: string, callback: AsyncCallback<string>): void | denormalizeUri?(uri: string, callback: AsyncCallback<string>): void | The two methods have the same meaning, invoking time, and parameters.| 29 | insert?(uri: string, valueBucket: rdb.ValuesBucket, callback: AsyncCallback<number>): void | insert?(uri: string, value: ValuesBucket, callback: AsyncCallback<number>): void | The two methods have the same meaning and invoking time, but slightly different parameter type. A simple reconstruction is required.| 30 | openFile?(uri: string, mode: string, callback: AsyncCallback<number>): void | NA | The stage model does not support cross-process URI access. You are advised to use [the **want** parameter to carry the file descriptor and file information](data-share-via-want.md) for cross-process file access.| 31 | getFileTypes?(uri: string, mimeTypeFilter: string, callback: AsyncCallback<Array<string>>): void | NA | The stage model does not support cross-process URI access. You are advised to use [the **want** parameter to carry the file descriptor and file information](data-share-via-want.md) for cross-process file access.| 32 | getType?(uri: string, callback: AsyncCallback<string>): void | NA | The stage model does not support cross-process URI access. You are advised to use [the **want** parameter to carry the file descriptor and file information](data-share-via-want.md) for cross-process file access.| 33 | executeBatch?(ops: Array<DataAbilityOperation>, callback: AsyncCallback<Array<DataAbilityResult>>): void | NA | This method is not provided in the stage model. You need to implement the functionality based on service functions.| 34 | call?(method: string, arg: string, extras: PacMap, callback: AsyncCallback<PacMap>): void | NA | This method is not provided in the stage model. You need to implement the functionality based on service functions.| 35 36 37## Switching a DataAbility of a Third-Party Application 38 39In the stage model, third-party applications cannot provide data services for other third-party applications. You can select a switching solution based on your service requirements. 40 41| Service Type| Switching Solution| 42| -------- | -------- | 43| Providing data for third-party applications| Match a scenario-specific [ExtensionAbility](../reference/apis/js-apis-bundleManager.md#extensionabilitytype).| 44| Providing data within the application| Extract the component code as a common module for other components to use.| 45