# Data Share Extension Ability

**DataShareExtensionAbility** provides extension abilities for data share services based on the ExtensionAbility framework.

>**NOTE**
>
>The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
>
>The APIs provided by this module are system APIs.
>
>The APIs of this module can be used only in the stage model.


## Modules to Import

```ts
import DataShareExtensionAbility from '@ohos.application.DataShareExtensionAbility'
```

## onCreate

onCreate?(want: Want, callback: AsyncCallback<void>): void

Called to initialize service logic of the server when the DataShare client connects to the DataShareExtensionAbility server. This API can be overridden as required.

**System capability**: SystemCapability.DistributedDataManager.DataShare.Provider

**Parameters**

| Name| Type| Mandatory| Description|
| ----- | ------ | ------ | ------ |
| want | [Want](js-apis-application-Want.md#want) | Yes | **Want** information, including the ability name and bundle name.|
| callback | AsyncCallback<void> | Yes| Callback that returns no value.|

**Example**

```ts
import rdb from '@ohos.data.rdb';

let DB_NAME = "DB00.db";
let TBL_NAME = "TBL00";
let DDL_TBL_CREATE = "CREATE TABLE IF NOT EXISTS "
+ TBL_NAME
+ " (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER, phoneNumber DOUBLE, isStudent BOOLEAN, Binary BINARY)";
let rdbStore;

export default class DataShareExtAbility extends DataShareExtensionAbility {
    onCreate(want: Want, callback: AsyncCallback<void>) {
        rdb.getRdbStore(this.context, {
            name: DB_NAME
        }, 1, function (err, data) {
            console.log('getRdbStore done, data : ' + data);
            rdbStore = data;
            rdbStore.executeSql(DDL_TBL_CREATE, [], function (err) {
                console.log('executeSql done, error message : ' + err);
            });
            if (callback) {
                callback();
            }
        });
    }
};
```

## getFileTypes

getFileTypes?(uri: string, mimeTypeFilter: string, callback: AsyncCallback&lt;Array&lt;string&gt;&gt;): void

Called by the server to obtain the Multipurpose Internet Mail Extensions (MIME) types supported by a file. This API can be overridden as required.

**System capability**: SystemCapability.DistributedDataManager.DataShare.Provider

**Parameters**

| Name          | Type                                    | Mandatory| Description                              |
| -------------- | ---------------------------------------- | ---- | ---------------------------------- |
| uri            | string                                   | Yes  | URI of the file.          |
| mimeTypeFilter | string                                   | Yes  | MIME types to match.      |
| callback       | AsyncCallback&lt;Array&lt;string&gt;&gt; | Yes  | Callback invoked to return the MIME types obtained.|

**Example**

```ts
export default class DataShareExtAbility extends DataShareExtensionAbility {
    getFileTypes(uri: string, mimeTypeFilter: string, callback: AsyncCallback<Array<string>>) {
        let err = {"code":0};
        let ret = new Array("type01", "type02", "type03");
        callback(err, ret);
    }
};
```

## openFile

openFile?(uri: string, mode: string, callback: AsyncCallback&lt;number&gt;): void

Called by the server to open a file. This method can be overridden as required.

**System capability**: SystemCapability.DistributedDataManager.DataShare.Provider

**Parameters**

| Name    | Type                 | Mandatory| Description                                      |
| -------- | --------------------- | ---- | ------------------------------------------ |
| uri      | string                | Yes  | URI of the file to open.       |
| mode     | string                | Yes  | File open mode, including read-only mode and read/write mode.|
| callback | AsyncCallback&lt;number&gt; | Yes  | Callback invoked to return the file descriptor.       |

**Example**

```ts
export default class DataShareExtAbility extends DataShareExtensionAbility {
    openFile(uri: string, mode: string, callback: AsyncCallback<number>) {
        let err = {"code":0};
        let fd = 0;
        callback(err,fd);
    }
};
```

## insert

insert?(uri: string, valueBucket: ValuesBucket, callback: AsyncCallback&lt;number&gt;): void

Called to insert data into the database. This API can be overridden as required.

**System capability**: SystemCapability.DistributedDataManager.DataShare.Provider

**Parameters**

| Name| Type| Mandatory| Description|
| ----- | ------ | ------ | ------ |
| uri |string | Yes | URI of the data to insert.|
| valueBucket |[ValuesBucket](js-apis-data-ValuesBucket.md#valuesbucket) | Yes| Data to insert.|
| callback |AsyncCallback&lt;number&gt; | Yes| Callback invoked to return the index of the data inserted.|

**Example**

```ts
export default class DataShareExtAbility extends DataShareExtensionAbility {
    insert(uri: string, valueBucket: ValuesBucket, callback: AsyncCallback<number>) {
        if (value == null) {
            console.info('invalid valueBuckets');
            return;
        }
        rdbStore.insert(TBL_NAME, value, function (err, ret) {
            console.info('callback ret:' + ret);
            if (callback != undefined) {
                callback(err, ret);
            }
        });
    }
};
```

## update

update?(uri: string, predicates: dataSharePredicates.DataSharePredicates, valueBucket: ValuesBucket, callback: AsyncCallback&lt;number&gt;): void

Called by the server to update data in the database. This API can be overridden as required.

**System capability**: SystemCapability.DistributedDataManager.DataShare.Provider

**Parameters**

| Name| Type| Mandatory| Description|
| ----- | ------ | ------ | ------ |
| uri | string | Yes | URI of the data to update.|
| predicates | [DataSharePredicates](js-apis-data-DataSharePredicates.md#datasharepredicates) | Yes | Filter criteria for updating data.|
| valueBucket | [ValuesBucket](js-apis-data-ValuesBucket.md#valuesbucket) | Yes| New data.|
| callback | AsyncCallback&lt;number&gt; | Yes| Callback invoked to return the number of updated data records.|

**Example**

```ts
export default class DataShareExtAbility extends DataShareExtensionAbility {
    update(uri: string, predicates: dataSharePredicates.DataSharePredicates, valueBucket: ValuesBucket, callback: AsyncCallback<number>) {
        if (predicates == null || predicates == undefined) {
            return;
        }
        rdbStore.update(TBL_NAME, value, predicates, function (err, ret) {
            if (callback != undefined) {
                callback(err, ret);
            }
        });
    }
};
```

## delete

delete?(uri: string, predicates: dataSharePredicates.DataSharePredicates, callback: AsyncCallback&lt;number&gt;): void

Called by the server to delete data from the database. This API can be overridden as required.

**System capability**: SystemCapability.DistributedDataManager.DataShare.Provider

**Parameters**

| Name      | Type                                                    | Mandatory| Description                              |
| ---------- | ------------------------------------------------------------ | ---- | ---------------------------------- |
| uri        | string                                                       | Yes  | URI of the data to delete.          |
| predicates | [DataSharePredicates](js-apis-data-DataSharePredicates.md#datasharepredicates) | Yes  | Filter criteria for deleting data.                    |
| callback   | AsyncCallback&lt;number&gt;                                  | Yes  | Callback invoked to return the number of data records deleted.|

**Example**

```ts
export default class DataShareExtAbility extends DataShareExtensionAbility {
    delete(uri: string, predicates: dataSharePredicates.DataSharePredicates, callback: AsyncCallback<number>) {
        if (predicates == null || predicates == undefined) {
            return;
        }
        rdbStore.delete(TBL_NAME, predicates, function (err, ret) {
            if (callback != undefined) {
                callback(err, ret);
            }
        });
    }
};
```

## query

query?(uri: string, predicates: dataSharePredicates.DataSharePredicates, columns: Array&lt;string&gt;, callback: AsyncCallback&lt;Object&gt;): void

Called by the server to query data from the database. This API can be overridden as required.

**System capability**: SystemCapability.DistributedDataManager.DataShare.Provider

**Parameters**

| Name| Type| Mandatory| Description|
| ----- | ------ | ------ | ------ |
| uri | string | Yes | URI of the data to query.|
| predicates | [DataSharePredicates](js-apis-data-DataSharePredicates.md#datasharepredicates) | Yes | Filter criteria for querying data.|
| columns | Array&lt;string&gt; | Yes| Columns to query. If this parameter is empty, all columns will be queried.|
| callback | AsyncCallback&lt;Object&gt; | Yes| Callback invoked to return the result set.|

**Example**

```ts
export default class DataShareExtAbility extends DataShareExtensionAbility {
    query(uri: string, predicates: dataSharePredicates.DataSharePredicates, columns: Array<string>, callback: AsyncCallback<Object>) {
        if (predicates == null || predicates == undefined) {
            return;
        }
        rdbStore.query(TBL_NAME, predicates, columns, function (err, resultSet) {
            if (resultSet != undefined) {
                console.info('resultSet.rowCount: ' + resultSet.rowCount);
            }
            if (callback != undefined) {
                callback(err, resultSet);
            }
        });
    }
};
```

## getType

getType?(uri: string, callback: AsyncCallback&lt;string&gt;): void

Called by the server to obtain the MIME type corresponding to the given URI. This API can be overridden as required.

**System capability**: SystemCapability.DistributedDataManager.DataShare.Provider

**Parameters**

| Name| Type| Mandatory| Description|
| ----- | ------ | ------ | ------ |
| uri | string | Yes | URI of the target data.|
| callback | AsyncCallback&lt;string&gt; | Yes| Callback invoked to return the MIME type obtained.|

**Example**

```ts
export default class DataShareExtAbility extends DataShareExtensionAbility {
    getType(uri: string, callback: AsyncCallback<string>) {
        let err = {"code":0};
        let ret = "image";
        callback(err, ret);
    }
};
```

## BatchInsert

BatchInsert?(uri: string, valueBuckets: Array&lt;ValuesBucket&gt;, callback: AsyncCallback&lt;number&gt;): void

Called by the server to insert batch data into the database. This API can be overridden as required.

**System capability**: SystemCapability.DistributedDataManager.DataShare.Provider

**Parameters**

| Name        | Type                                                    | Mandatory| Description                            |
| ------------ | ------------------------------------------------------------ | ---- | -------------------------------- |
| uri          | string                                                       | Yes  | URI of the data to insert.    |
| valueBuckets | Array&lt;[ValuesBucket](js-apis-data-ValuesBucket.md#valuesbucket)&gt; | Yes  | Data to insert.          |
| callback     | AsyncCallback&lt;number&gt;                                  | Yes  | Callback invoked to return the number of inserted data records.|

**Example**

```ts
export default class DataShareExtAbility extends DataShareExtensionAbility {
    batchInsert(uri: string, valueBuckets: Array<ValuesBucket>, callback: AsyncCallback<number>) {
        if (valueBuckets == null || valueBuckets.length == undefined) {
            console.info('invalid valueBuckets');
            return;
        }
        let resultNum = valueBuckets.length
        valueBuckets.forEach(vb => {
            rdbStore.insert(TBL_NAME, vb, function (err, ret) {
                if (callback != undefined) {
                    callback(err, resultNum);
                }
            });
        });
    }
};
```

## normalizeUri

normalizeUri?(uri: string, callback: AsyncCallback&lt;string&gt;): void

Called by the server to normalize the specified URI. This API can be overridden as required.

**System capability**: SystemCapability.DistributedDataManager.DataShare.Provider

**Parameters**

| Name    | Type                 | Mandatory| Description                   |
| -------- | --------------------- | ---- | ----------------------- |
| uri      | string                | Yes  | [URI](js-apis-uri.md#uri) to normalize.|
| callback | AsyncCallback&lt;string&gt; | Yes  | Callback used to return the result. If the operation is successful, the normalized URI is returned. Otherwise, **null** is returned.|

**Example**

```ts
export default class DataShareExtAbility extends DataShareExtensionAbility {
    normalizeUri(uri: string, callback: AsyncCallback<string>) {
        let err = {"code":0};
        let ret = "normalize+" + uri;
        callback(err, ret);
    }
};
```

## denormalizeUri

denormalizeUri?(uri: string, callback: AsyncCallback&lt;string&gt;): void

Called by the server to denormalize the specified URI. This method can be overridden as required.

**System capability**: SystemCapability.DistributedDataManager.DataShare.Provider

**Parameters**

| Name    | Type                 | Mandatory| Description                   |
| -------- | --------------------- | ---- | ----------------------- |
| uri      | string                | Yes  | [URI](js-apis-uri.md#uri) to denormalize.|
| callback | AsyncCallback&lt;string&gt; | Yes  | Callback used to return the result. If the operation is successful, the URI obtained is returned. If the URI passed in is returned, denormalization is not required. If denormalization is not supported, **null** is returned.|

**Example**

```ts
export default class DataShareExtAbility extends DataShareExtensionAbility {
    denormalizeUri(uri: string, callback: AsyncCallback<string>) {
        let err = {"code":0};
        let ret = "denormalize+" + uri;
        callback(err, ret);
    }
};
```