# 通知订阅扩展能力开发步骤 ## 接口说明 |接口名|描述| |:----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:----------------------------------------------------------------------------------------------------------------------------------| |[onDestroy(): void](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-notificationsubscriberextensionability#ondestroy)|[通知订阅](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/notification-glossary#notification-subscription通知订阅)扩展被销毁时的回调。| |[onReceiveMessage(notificationInfo: NotificationInfo): void](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-notificationsubscriberextensionability#onreceivemessage)|收到通知时的回调。| |[onCancelMessages(hashCodes: Array): void](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-notificationsubscriberextensionability#oncancelmessages)|取消通知时的回调。| ## 前提条件 申请[ohos.permission.SUBSCRIBE_NOTIFICATION](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/restricted-permissions#ohospermissionsubscribe_notification)权限。 ## 开发步骤 开发者在实现[NotificationSubscriberExtensionAbility](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-notificationsubscriberextensionability)提供方时，需在[DevEco Studio](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/ide-tools-overview)工程中新建一个NotificationSubscriberExtensionAbility。具体步骤如下。 1. 在entry/src/main/ets/创建目录extensionability。 2. 在entry/src/main/ets/extensionability目录下创建NotificationSubscriberExtAbility.ets，其内容如下。 ```TypeScript import { hilog } from '@kit.PerformanceAnalysisKit'; import { notificationExtensionSubscription, NotificationSubscriberExtensionAbility } from '@kit.NotificationKit'; // ... const DOMAIN = 0x0000; // ... export class NotificationSubscriberExtAbility extends NotificationSubscriberExtensionAbility { // ... onDestroy(): void { hilog.info(DOMAIN, 'testTag', 'onDestroy'); // ... } // ... onReceiveMessage(notificationInfo: notificationExtensionSubscription.NotificationInfo): void { hilog.info(DOMAIN, 'testTag', `on receive message ${JSON.stringify(notificationInfo)}`) // ... } // ... onCancelMessages(hashCodes: Array): void { hilog.info(DOMAIN, 'testTag', `on cancel message ${JSON.stringify(hashCodes)}`) // ... } // ... } ``` 3. 使用[蓝牙模块](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/connectivity-kit-intro#蓝牙简介)接口与穿戴设备配对（蓝牙处于配对状态）并获取地址，然后通过[subscribe](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-notificationextensionsubscription#notificationextensionsubscriptionsubscribe)/[unsubscribe](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-notificationextensionsubscription#notificationextensionsubscriptionunsubscribe)接口订阅或取消订阅通知。 4. 实现[NotificationSubscriberExtensionAbility](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-notificationsubscriberextensionability)后，还需要在合适的时机调用[openSubscriptionSettingsWithResult](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-notificationextensionsubscription#notificationextensionsubscriptionopensubscriptionsettingswithresult)接口，打开通知扩展订阅设置页面，引导用户授予获取本机通知的权限，该页面以半模态弹窗显示，并在弹窗关闭时返回授权的结果。建议在设备管理页面提供一个[通知授权](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/notification-glossary#notification-authorization通知授权)的按钮，用户点击按钮则调用[openSubscriptionSettingsWithResult](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-notificationextensionsubscription#notificationextensionsubscriptionopensubscriptionsettingswithresult)接口。 5. 在应用的module.json5文件中配置extensionAbilities。 ```JSON5 { "name": "NotificationSubscriberExtAbility", "srcEntry": "./ets/extensionability/NotificationSubscriberExtAbility.ets", "type": "notificationSubscriber", "description": "$string:NotificationSubscriberExtAbility_desc", "icon": "$media:layered_image", "label": "$string:NotificationSubscriberExtAbility_label", "exported": true } ``` 6. 在应用的string.json文件中添加 ```json [ { "name": "NotificationSubscriberExtAbility_desc", "value": "description" }, { "name": "NotificationSubscriberExtAbility_label", "value": "ThirdPartyWearableApp" } ] ``` 7. 示例仅为传统蓝牙连接示例，开发者也可选用低功耗蓝牙连接方式。 8. 用户收到消息后，如果蓝牙连接是无效的，则需建立蓝牙连接。 9. 假如蓝牙连接已经存在，则直接使用此连接发送消息。 10. 如果使用该蓝牙连接发送消息失败，则需要重新建立蓝牙连接，连接成功后即可发送消息。 11. 需要申请权限[ohos.permission.ACCESS_BLUETOOTH](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/permissions-for-all-user#ohospermissionaccess_bluetooth)。如何配置和申请权限，具体操作请参考[声明权限](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/declare-permissions)和[向用户申请授权](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/request-user-authorization)。 ```TypeScript import { hilog } from '@kit.PerformanceAnalysisKit'; import { notificationExtensionSubscription, NotificationSubscriberExtensionAbility } from '@kit.NotificationKit'; import { BusinessError } from '@kit.BasicServicesKit'; import { socket } from '@kit.ConnectivityKit' import { util } from '@kit.ArkTS'; const DOMAIN = 0x0000; class TransferInfo { public type: string = '' public info: notificationExtensionSubscription.NotificationInfo | undefined public cancelHashCodes: Array | undefined } // Spp means Serial Port Profile class SppClientManager { private clientNumber: number = -1; private peerDevice: string = ''; private connectPromise: Promise | null = null; constructor(peerDevice: string) { this.peerDevice = peerDevice } public isConnect(): boolean { return this.clientNumber !== -1; } public startConnect(): Promise { if (this.isConnect()) { return Promise.resolve(true); } if (this.connectPromise) { return this.connectPromise; } this.connectPromise = new Promise((resolve) => { let option: socket.SppOptions = { uuid: '00009999-0000-1000-8000-00805F9B34FB', // UUID of the server to connect to, ensure server support secure: false, type: socket.SppType.SPP_RFCOMM }; socket.sppConnect(this.peerDevice, option, (err: BusinessError, num: number) => { this.connectPromise = null; if (err) { hilog.error(DOMAIN, 'testTag', `cpp connect failed, errCode: ${err.code}, errMessage: ${err.message}`); resolve(false); } else { hilog.info(DOMAIN, 'testTag', `spp connect success clientNumber: ${num}`); this.clientNumber = num; socket.on('sppRead', this.clientNumber, this.read); resolve(true); } }); }); return this.connectPromise; } private sendData(jsonStr: string) { if (!this.isConnect()) { hilog.error(DOMAIN, 'testTag', `server is not connected`); return; } if (!jsonStr) { hilog.error(DOMAIN, 'testTag', 'json is empty'); return; } hilog.info(DOMAIN, 'testTag', `prepare sending data to client ${this.clientNumber}`); const textEncoder:util.TextEncoder = new util.TextEncoder(); const uint8Array: Uint8Array = textEncoder.encodeInto(jsonStr); const arrayBuffer = uint8Array.buffer; socket.sppWrite(this.clientNumber, arrayBuffer); hilog.info(DOMAIN, 'testTag', `sending success size: ${arrayBuffer.byteLength} bytes, data: ${jsonStr}`); } public sendNotificationData(notificationInfo: notificationExtensionSubscription.NotificationInfo) { let info: TransferInfo = { type: 'publish', info: notificationInfo, cancelHashCodes: undefined }; let jsonStr = JSON.stringify(info); this.sendData(jsonStr); } public sendCancelNotificationData(cancelHashCodes: Array) { let info: TransferInfo = { type: 'cancel', cancelHashCodes: cancelHashCodes, info: undefined }; let jsonStr = JSON.stringify(info); this.sendData(jsonStr); } public read = (dataBuffer: ArrayBuffer) => { let data = new Uint8Array(dataBuffer); hilog.info(DOMAIN, 'testTag', `client data: ${JSON.stringify(data)}`); }; public stopConnect() { hilog.info(DOMAIN, 'testTag', `closeSppClient ${this.clientNumber}`); this.connectPromise = null; try { socket.off('sppRead', this.clientNumber, this.read); } catch (err) { hilog.error(DOMAIN, 'testTag', `off sppRead errCode: ${err.code}, errMessage: ${err.message}`); } try { socket.sppCloseClientSocket(this.clientNumber); } catch (err) { hilog.error(DOMAIN, 'testTag', `stopConnect errCode: ${err.code}, errMessage: ${err.message}`); } this.clientNumber = -1; } } // export SppClientManager; export class NotificationSubscriberExtAbility extends NotificationSubscriberExtensionAbility { private sppClientManager: SppClientManager | undefined; onDestroy(): void { hilog.info(DOMAIN, 'testTag', 'onDestroy'); this.sppClientManager?.stopConnect(); } // Called back when a notification is published. onReceiveMessage(notificationInfo: notificationExtensionSubscription.NotificationInfo): void { hilog.info(DOMAIN, 'testTag', `on receive message ${JSON.stringify(notificationInfo)}`) notificationExtensionSubscription.getSubscribeInfo() .then(async (info) => { if (this.sppClientManager == undefined) { this.sppClientManager = new SppClientManager(info[0].addr); } if (this.sppClientManager.isConnect()) { this.sendPublishWithRetry(notificationInfo); } else { let connected = await this.sppClientManager.startConnect(); if (connected) { this.sendPublishWithRetry(notificationInfo); } else { hilog.error(DOMAIN, 'testTag', `startConnect failed, skip send`); } } }).catch((err: BusinessError) => { hilog.error(DOMAIN, 'testTag', `notificationExtensionSubscription failed, errCode ${err.code}, errorMessage ${err.message}`); }); } // Sends a publish notification and retries once upon failure. private async sendPublishWithRetry(notificationInfo: notificationExtensionSubscription.NotificationInfo) { try { this.sppClientManager!.sendNotificationData(notificationInfo); } catch (err) { hilog.error(DOMAIN, 'testTag', `send failed, errCode ${err.code}, errorMessage ${err.message}, and retry one times`); this.sppClientManager!.stopConnect(); let connected = await this.sppClientManager!.startConnect(); if (connected) { this.sppClientManager!.sendNotificationData(notificationInfo); } else { hilog.error(DOMAIN, 'testTag', `retry startConnect failed, skip send`); } } } // Called back when notifications are cancelled. onCancelMessages(hashCodes: Array): void { hilog.info(DOMAIN, 'testTag', `on cancel message ${JSON.stringify(hashCodes)}`) notificationExtensionSubscription.getSubscribeInfo() .then(async (info) => { if (this.sppClientManager == undefined) { this.sppClientManager = new SppClientManager(info[0].addr); } if (this.sppClientManager.isConnect()) { this.sendCancelWithRetry(hashCodes); } else { let connected = await this.sppClientManager.startConnect(); if (connected) { this.sendCancelWithRetry(hashCodes); } else { hilog.error(DOMAIN, 'testTag', `startConnect failed, skip send`); } } }).catch((err: BusinessError) => { hilog.error(DOMAIN, 'testTag', `notificationExtensionSubscription failed, errCode ${err.code}, errorMessage ${err.message}`); }); } // Retries a cancel operation if it fails. private async sendCancelWithRetry(hashCodes: string[]) { try { this.sppClientManager!.sendCancelNotificationData(hashCodes); } catch (err) { hilog.error(DOMAIN, 'testTag', `send failed, errCode ${err.code}, errorMessage ${err.message}, and retry one times`); this.sppClientManager!.stopConnect(); let connected = await this.sppClientManager!.startConnect(); if (connected) { this.sppClientManager!.sendCancelNotificationData(hashCodes); } else { hilog.error(DOMAIN, 'testTag', `retry startConnect failed, skip send`); } } } } ```