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JavaScript中的异步设置器/获取器

[英]Async setter / getter in JavaScript

我正在使用需要大量异步操作的Web蓝牙。 我已经实现了属性(例如设备名称)的setter和getter。 异步getter和setter方法不被默认支持ES6,所以我用以下解决方法是建议在这里

get name() {
  return ( async () => {
    try {
      const data = await this._readData(this.nameCharacteristic);
      const decoder = new TextDecoder("utf-8");
      const name = decoder.decode(data);
      return name;
    } 
    catch (error) {
      return error;
    }
  })();
}

和:

set name(name) {
  return ( async (name) => {
    const byteArray = new Uint8Array(name.length);
    for (let i = 0; i < name.length; i += 1) {
      byteArray[i] = name.charCodeAt(i);
    }
    return await this._writeData(this.nameCharacteristic, byteArray);
  })(name);
}

我可以使用吸气剂成功完成以下操作:

await device.connect();
await device.name;
await device.<some async BLE operation>

但是,以下带有setter的操作会导致setter的参考错误“ Uncaught ReferenceError:分配中的无效左侧”:

await device.connect();
await device.name = "newName";
await device.<some async BLE operation>

如果删除await关键字,该错误已修复,但是脚本将失败,因为它将同时尝试两次GATT操作,这是不支持的。

因此,看来我只能等待吸气剂而不是塞特剂。 我对getter的实现是否有问题,导致这种情况? 进行异步操作时,我是否必须返回使用device.nameSet()类的函数而不是setter?

对于记录, _writeData()_readData()如下所示:

async _writeData(characteristic, dataArray) {
  if (!this.bleIsBusy) {
    try {
      this.bleIsBusy = true;
      await characteristic.writeValue(dataArray);
      this.bleIsBusy = false;
    }
    catch (error) {
      return error;
    }
    return Promise.resolve();
  }
  else {
    return Promise.reject(new Error("GATT operation already pending"));
  }
}

async _readData(characteristic) {
  if (!this.bleIsBusy) {
    try {
      this.bleIsBusy = true;
      const dataArray = await characteristic.readValue();
      this.bleIsBusy = false;

      return dataArray;
    }
    catch (error) {
      return error;
    }
  }
  else {
    return Promise.reject(new Error("GATT operation already pending"));
  }
}

也许尝试设置从返回的值,以await this._writeData(this.nameCharacteristic, byteArray); ...

set name(name) {
  return ( async (name) => {
    const byteArray = new Uint8Array(name.length);
    for (let i = 0; i < name.length; i += 1) {
      byteArray[i] = name.charCodeAt(i);
    }
    const result = await this._writeData(this.nameCharacteristic, byteArray);
    return result;
  })(name);
}

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