Fatal编程技术网
  • firebase/
  • Firebase 在flatter中返回Null的可调用云函数 我的目标是：

Firebase 在flatter中返回Null的可调用云函数 我的目标是：

firebase flutter

Firebase 在flatter中返回Null的可调用云函数 我的目标是：,firebase,flutter,google-cloud-functions,flutter-web,Firebase,Flutter,Google Cloud Functions,Flutter Web,我希望在我的flatter应用程序中调用云函数，该函数从Python FastAPI服务器检索JSON obj，并在警报对话框中显示内容 错误： 我的颤振应用程序中的可调用函数服务接收空值。我的警报对话框显示由我的代码触发的“空值错误” 云端操作： 我的云功能分为两部分： 在可调用的Http函数中从客户端（颤振应用程序）接收数据 调用pythonapi=>returntocloud函数，返回给客户端 云功能： exports.getRandomPassword = functions.ht

我希望在我的flatter应用程序中调用云函数，该函数从Python FastAPI服务器检索JSON obj，并在警报对话框中显示内容

错误： 我的颤振应用程序中的可调用函数服务接收空值。我的警报对话框显示由我的代码触发的“空值错误”

云端操作： 我的云功能分为两部分：
  • 在可调用的Http函数中从客户端（颤振应用程序）接收数据
  • 调用pythonapi=>returntocloud函数，返回给客户端
云功能：

exports.getRandomPassword = functions.https.onCall(async (data, context) => {
  const useSymbols = data.useSymbols;
  const pwLength= data.pwLength;

  const debug ={
    received_data_type: typeof data,
    received_data:data,
    pwLen_type: typeof pwLength,
    pwLength,
    useSymbols_type:typeof useSymbols,
    useSymbols,
  }

  console.log(debug);
  await callAPI(pwLength,useSymbols).then((res:any) =>{
    console.log(`Resulting Payload: ${res}`);
    return res});

});


async function callAPI(pwLength: any, useSymbols: any) {
  // BUILD URL STRING WITH PARAMS
  const ROOT_URL = `http://[IP_Address]/password?pwd_length=${pwLength}&use_symbols=${useSymbols}`;
  let res;
  // let password: any; // password to be received

  await http.get(ROOT_URL)
    .then((response: any) => {
      console.log("TO APP "+JSON.stringify(response));
      console.log(response.getBody());
      res = response.getBody() as Map<any, any>;

    })
    .catch((err: any) => {
      console.log(err);
      res= err;
    });

  return res;
}

                        onPressed: () async {
                          // call cloud function & use set state to store pw
                          await getPassword().then((String result) {
                            setState(() {
                              password = result;
                            });
                          });
                          showDialog(
                              context: context,
                              builder: (context) => DisplayPassword());
                        },

Future<String> getPassword() async {
  var pw;
  final HttpsCallable callable = new CloudFunctions()
      .getHttpsCallable(functionName: 'getRandomPassword')
        ..timeout = const Duration(seconds: 30);

  try {
    await callable.call(
      <String, dynamic>{
        'pwLength': 10,
        'useSymbols': true,
      },
    ).then((value) {
      print(value.data);
      print(value.data.runtimeType);
      pw = value.data;
      return pw;
    });
  } on CloudFunctionsException catch (e) {
    print('caught firebase functions exception');
    print('Code: ${e.code}\nmessage: ${e.message}\ndetails: ${e.details}');

    return '${e.details}';
  } catch (e) {
    print('caught generic exception');
    print(e);
    return 'caught generic exception\n$e';
  }
}

class DisplayPassword extends StatelessWidget {
  final String pw = (_MyPasswordGenPageState().password == null)
      ? 'null value error'
      : _MyPasswordGenPageState().password;

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: Text(pw),
    );
  }
}


    dynamic result =
        await callable.call(<String, dynamic>{
      'pwLength': 10,
      'useSymbols': true,
      //await the result before continuing
    });

    setState(() {
      // convert hashmap to list and get first val
      password = result.data.values.toList()[0];
      isLoading = false; // remove loading indicator
    });


  showDialog(
      context: context,
      builder: (context) =>
          DisplayPassword(password));




    class DisplayPassword extends StatelessWidget {
      var password; // check if null
      DisplayPassword(this.password); // constructor
    
      @override
      Widget build(BuildContext context) {
        // make sure null value isn't being passed to alert dialog widget
        if (password == null) {
          password = 'null value error';
        }
    
        return AlertDialog(
          title: Text(password),
        );
      }
    }



exports.getRandomPassword = functions.https.onCall(async (data, context) => {
  const useSymbols = data.useSymbols;
  const pwLength= data.pwLength;
  let password;
  password = await callAPI(pwLength,useSymbols);

  const debug ={
    received_data_type: typeof data,
    received_data:data,
    pwLen_type: typeof pwLength,
    pwLength,
    useSymbols_type:typeof useSymbols,
    useSymbols,
    ResultingPayloadType: typeof password,
    ResultingPayload: password,

  }

  console.log(debug);

  return Promise.resolve(password)

});


async function callAPI(pwLength: any, useSymbols: any) {
  // BUILD URL STRING WITH PARAMS
  const ROOT_URL = `http://[My_Api_IP_Address]/password?pwd_length=${pwLength}&use_symbols=${useSymbols}`;

  const res = await http.get(ROOT_URL);
  console.log(res.getBody());
  return res.getBody() as Map<String , any>;

}
Python FastAPI调用：

exports.getRandomPassword = functions.https.onCall(async (data, context) => {
  const useSymbols = data.useSymbols;
  const pwLength= data.pwLength;

  const debug ={
    received_data_type: typeof data,
    received_data:data,
    pwLen_type: typeof pwLength,
    pwLength,
    useSymbols_type:typeof useSymbols,
    useSymbols,
  }

  console.log(debug);
  await callAPI(pwLength,useSymbols).then((res:any) =>{
    console.log(`Resulting Payload: ${res}`);
    return res});

});


async function callAPI(pwLength: any, useSymbols: any) {
  // BUILD URL STRING WITH PARAMS
  const ROOT_URL = `http://[IP_Address]/password?pwd_length=${pwLength}&use_symbols=${useSymbols}`;
  let res;
  // let password: any; // password to be received

  await http.get(ROOT_URL)
    .then((response: any) => {
      console.log("TO APP "+JSON.stringify(response));
      console.log(response.getBody());
      res = response.getBody() as Map<any, any>;

    })
    .catch((err: any) => {
      console.log(err);
      res= err;
    });

  return res;
}

                        onPressed: () async {
                          // call cloud function & use set state to store pw
                          await getPassword().then((String result) {
                            setState(() {
                              password = result;
                            });
                          });
                          showDialog(
                              context: context,
                              builder: (context) => DisplayPassword());
                        },

Future<String> getPassword() async {
  var pw;
  final HttpsCallable callable = new CloudFunctions()
      .getHttpsCallable(functionName: 'getRandomPassword')
        ..timeout = const Duration(seconds: 30);

  try {
    await callable.call(
      <String, dynamic>{
        'pwLength': 10,
        'useSymbols': true,
      },
    ).then((value) {
      print(value.data);
      print(value.data.runtimeType);
      pw = value.data;
      return pw;
    });
  } on CloudFunctionsException catch (e) {
    print('caught firebase functions exception');
    print('Code: ${e.code}\nmessage: ${e.message}\ndetails: ${e.details}');

    return '${e.details}';
  } catch (e) {
    print('caught generic exception');
    print(e);
    return 'caught generic exception\n$e';
  }
}

class DisplayPassword extends StatelessWidget {
  final String pw = (_MyPasswordGenPageState().password == null)
      ? 'null value error'
      : _MyPasswordGenPageState().password;

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: Text(pw),
    );
  }
}


    dynamic result =
        await callable.call(<String, dynamic>{
      'pwLength': 10,
      'useSymbols': true,
      //await the result before continuing
    });

    setState(() {
      // convert hashmap to list and get first val
      password = result.data.values.toList()[0];
      isLoading = false; // remove loading indicator
    });


  showDialog(
      context: context,
      builder: (context) =>
          DisplayPassword(password));




    class DisplayPassword extends StatelessWidget {
      var password; // check if null
      DisplayPassword(this.password); // constructor
    
      @override
      Widget build(BuildContext context) {
        // make sure null value isn't being passed to alert dialog widget
        if (password == null) {
          password = 'null value error';
        }
    
        return AlertDialog(
          title: Text(password),
        );
      }
    }



exports.getRandomPassword = functions.https.onCall(async (data, context) => {
  const useSymbols = data.useSymbols;
  const pwLength= data.pwLength;
  let password;
  password = await callAPI(pwLength,useSymbols);

  const debug ={
    received_data_type: typeof data,
    received_data:data,
    pwLen_type: typeof pwLength,
    pwLength,
    useSymbols_type:typeof useSymbols,
    useSymbols,
    ResultingPayloadType: typeof password,
    ResultingPayload: password,

  }

  console.log(debug);

  return Promise.resolve(password)

});


async function callAPI(pwLength: any, useSymbols: any) {
  // BUILD URL STRING WITH PARAMS
  const ROOT_URL = `http://[My_Api_IP_Address]/password?pwd_length=${pwLength}&use_symbols=${useSymbols}`;

  const res = await http.get(ROOT_URL);
  console.log(res.getBody());
  return res.getBody() as Map<String , any>;

}
我的颤振获取密码（）函数：

exports.getRandomPassword = functions.https.onCall(async (data, context) => {
  const useSymbols = data.useSymbols;
  const pwLength= data.pwLength;

  const debug ={
    received_data_type: typeof data,
    received_data:data,
    pwLen_type: typeof pwLength,
    pwLength,
    useSymbols_type:typeof useSymbols,
    useSymbols,
  }

  console.log(debug);
  await callAPI(pwLength,useSymbols).then((res:any) =>{
    console.log(`Resulting Payload: ${res}`);
    return res});

});


async function callAPI(pwLength: any, useSymbols: any) {
  // BUILD URL STRING WITH PARAMS
  const ROOT_URL = `http://[IP_Address]/password?pwd_length=${pwLength}&use_symbols=${useSymbols}`;
  let res;
  // let password: any; // password to be received

  await http.get(ROOT_URL)
    .then((response: any) => {
      console.log("TO APP "+JSON.stringify(response));
      console.log(response.getBody());
      res = response.getBody() as Map<any, any>;

    })
    .catch((err: any) => {
      console.log(err);
      res= err;
    });

  return res;
}

                        onPressed: () async {
                          // call cloud function & use set state to store pw
                          await getPassword().then((String result) {
                            setState(() {
                              password = result;
                            });
                          });
                          showDialog(
                              context: context,
                              builder: (context) => DisplayPassword());
                        },

Future<String> getPassword() async {
  var pw;
  final HttpsCallable callable = new CloudFunctions()
      .getHttpsCallable(functionName: 'getRandomPassword')
        ..timeout = const Duration(seconds: 30);

  try {
    await callable.call(
      <String, dynamic>{
        'pwLength': 10,
        'useSymbols': true,
      },
    ).then((value) {
      print(value.data);
      print(value.data.runtimeType);
      pw = value.data;
      return pw;
    });
  } on CloudFunctionsException catch (e) {
    print('caught firebase functions exception');
    print('Code: ${e.code}\nmessage: ${e.message}\ndetails: ${e.details}');

    return '${e.details}';
  } catch (e) {
    print('caught generic exception');
    print(e);
    return 'caught generic exception\n$e';
  }
}

class DisplayPassword extends StatelessWidget {
  final String pw = (_MyPasswordGenPageState().password == null)
      ? 'null value error'
      : _MyPasswordGenPageState().password;

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: Text(pw),
    );
  }
}


    dynamic result =
        await callable.call(<String, dynamic>{
      'pwLength': 10,
      'useSymbols': true,
      //await the result before continuing
    });

    setState(() {
      // convert hashmap to list and get first val
      password = result.data.values.toList()[0];
      isLoading = false; // remove loading indicator
    });


  showDialog(
      context: context,
      builder: (context) =>
          DisplayPassword(password));




    class DisplayPassword extends StatelessWidget {
      var password; // check if null
      DisplayPassword(this.password); // constructor
    
      @override
      Widget build(BuildContext context) {
        // make sure null value isn't being passed to alert dialog widget
        if (password == null) {
          password = 'null value error';
        }
    
        return AlertDialog(
          title: Text(password),
        );
      }
    }



exports.getRandomPassword = functions.https.onCall(async (data, context) => {
  const useSymbols = data.useSymbols;
  const pwLength= data.pwLength;
  let password;
  password = await callAPI(pwLength,useSymbols);

  const debug ={
    received_data_type: typeof data,
    received_data:data,
    pwLen_type: typeof pwLength,
    pwLength,
    useSymbols_type:typeof useSymbols,
    useSymbols,
    ResultingPayloadType: typeof password,
    ResultingPayload: password,

  }

  console.log(debug);

  return Promise.resolve(password)

});


async function callAPI(pwLength: any, useSymbols: any) {
  // BUILD URL STRING WITH PARAMS
  const ROOT_URL = `http://[My_Api_IP_Address]/password?pwd_length=${pwLength}&use_symbols=${useSymbols}`;

  const res = await http.get(ROOT_URL);
  console.log(res.getBody());
  return res.getBody() as Map<String , any>;

}
注意* 我想将密码检索保留为一种云功能，这样它就可以在web应用程序和移动应用程序上使用。不过，如果有更好的解决方案出现，我愿意重构整个操作

解决方案：
  • 对无状态小部件使用构造函数
  • 避免
    。然后（）
  • 在
    async
    函数中调用云函数时，应该返回
    Promise.resolve（）
点击按钮：

exports.getRandomPassword = functions.https.onCall(async (data, context) => {
  const useSymbols = data.useSymbols;
  const pwLength= data.pwLength;

  const debug ={
    received_data_type: typeof data,
    received_data:data,
    pwLen_type: typeof pwLength,
    pwLength,
    useSymbols_type:typeof useSymbols,
    useSymbols,
  }

  console.log(debug);
  await callAPI(pwLength,useSymbols).then((res:any) =>{
    console.log(`Resulting Payload: ${res}`);
    return res});

});


async function callAPI(pwLength: any, useSymbols: any) {
  // BUILD URL STRING WITH PARAMS
  const ROOT_URL = `http://[IP_Address]/password?pwd_length=${pwLength}&use_symbols=${useSymbols}`;
  let res;
  // let password: any; // password to be received

  await http.get(ROOT_URL)
    .then((response: any) => {
      console.log("TO APP "+JSON.stringify(response));
      console.log(response.getBody());
      res = response.getBody() as Map<any, any>;

    })
    .catch((err: any) => {
      console.log(err);
      res= err;
    });

  return res;
}

                        onPressed: () async {
                          // call cloud function & use set state to store pw
                          await getPassword().then((String result) {
                            setState(() {
                              password = result;
                            });
                          });
                          showDialog(
                              context: context,
                              builder: (context) => DisplayPassword());
                        },

Future<String> getPassword() async {
  var pw;
  final HttpsCallable callable = new CloudFunctions()
      .getHttpsCallable(functionName: 'getRandomPassword')
        ..timeout = const Duration(seconds: 30);

  try {
    await callable.call(
      <String, dynamic>{
        'pwLength': 10,
        'useSymbols': true,
      },
    ).then((value) {
      print(value.data);
      print(value.data.runtimeType);
      pw = value.data;
      return pw;
    });
  } on CloudFunctionsException catch (e) {
    print('caught firebase functions exception');
    print('Code: ${e.code}\nmessage: ${e.message}\ndetails: ${e.details}');

    return '${e.details}';
  } catch (e) {
    print('caught generic exception');
    print(e);
    return 'caught generic exception\n$e';
  }
}

class DisplayPassword extends StatelessWidget {
  final String pw = (_MyPasswordGenPageState().password == null)
      ? 'null value error'
      : _MyPasswordGenPageState().password;

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: Text(pw),
    );
  }
}


    dynamic result =
        await callable.call(<String, dynamic>{
      'pwLength': 10,
      'useSymbols': true,
      //await the result before continuing
    });

    setState(() {
      // convert hashmap to list and get first val
      password = result.data.values.toList()[0];
      isLoading = false; // remove loading indicator
    });


  showDialog(
      context: context,
      builder: (context) =>
          DisplayPassword(password));




    class DisplayPassword extends StatelessWidget {
      var password; // check if null
      DisplayPassword(this.password); // constructor
    
      @override
      Widget build(BuildContext context) {
        // make sure null value isn't being passed to alert dialog widget
        if (password == null) {
          password = 'null value error';
        }
    
        return AlertDialog(
          title: Text(password),
        );
      }
    }



exports.getRandomPassword = functions.https.onCall(async (data, context) => {
  const useSymbols = data.useSymbols;
  const pwLength= data.pwLength;
  let password;
  password = await callAPI(pwLength,useSymbols);

  const debug ={
    received_data_type: typeof data,
    received_data:data,
    pwLen_type: typeof pwLength,
    pwLength,
    useSymbols_type:typeof useSymbols,
    useSymbols,
    ResultingPayloadType: typeof password,
    ResultingPayload: password,

  }

  console.log(debug);

  return Promise.resolve(password)

});


async function callAPI(pwLength: any, useSymbols: any) {
  // BUILD URL STRING WITH PARAMS
  const ROOT_URL = `http://[My_Api_IP_Address]/password?pwd_length=${pwLength}&use_symbols=${useSymbols}`;

  const res = await http.get(ROOT_URL);
  console.log(res.getBody());
  return res.getBody() as Map<String , any>;

}
云功能：

exports.getRandomPassword = functions.https.onCall(async (data, context) => {
  const useSymbols = data.useSymbols;
  const pwLength= data.pwLength;

  const debug ={
    received_data_type: typeof data,
    received_data:data,
    pwLen_type: typeof pwLength,
    pwLength,
    useSymbols_type:typeof useSymbols,
    useSymbols,
  }

  console.log(debug);
  await callAPI(pwLength,useSymbols).then((res:any) =>{
    console.log(`Resulting Payload: ${res}`);
    return res});

});


async function callAPI(pwLength: any, useSymbols: any) {
  // BUILD URL STRING WITH PARAMS
  const ROOT_URL = `http://[IP_Address]/password?pwd_length=${pwLength}&use_symbols=${useSymbols}`;
  let res;
  // let password: any; // password to be received

  await http.get(ROOT_URL)
    .then((response: any) => {
      console.log("TO APP "+JSON.stringify(response));
      console.log(response.getBody());
      res = response.getBody() as Map<any, any>;

    })
    .catch((err: any) => {
      console.log(err);
      res= err;
    });

  return res;
}

                        onPressed: () async {
                          // call cloud function & use set state to store pw
                          await getPassword().then((String result) {
                            setState(() {
                              password = result;
                            });
                          });
                          showDialog(
                              context: context,
                              builder: (context) => DisplayPassword());
                        },

Future<String> getPassword() async {
  var pw;
  final HttpsCallable callable = new CloudFunctions()
      .getHttpsCallable(functionName: 'getRandomPassword')
        ..timeout = const Duration(seconds: 30);

  try {
    await callable.call(
      <String, dynamic>{
        'pwLength': 10,
        'useSymbols': true,
      },
    ).then((value) {
      print(value.data);
      print(value.data.runtimeType);
      pw = value.data;
      return pw;
    });
  } on CloudFunctionsException catch (e) {
    print('caught firebase functions exception');
    print('Code: ${e.code}\nmessage: ${e.message}\ndetails: ${e.details}');

    return '${e.details}';
  } catch (e) {
    print('caught generic exception');
    print(e);
    return 'caught generic exception\n$e';
  }
}

class DisplayPassword extends StatelessWidget {
  final String pw = (_MyPasswordGenPageState().password == null)
      ? 'null value error'
      : _MyPasswordGenPageState().password;

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: Text(pw),
    );
  }
}


    dynamic result =
        await callable.call(<String, dynamic>{
      'pwLength': 10,
      'useSymbols': true,
      //await the result before continuing
    });

    setState(() {
      // convert hashmap to list and get first val
      password = result.data.values.toList()[0];
      isLoading = false; // remove loading indicator
    });


  showDialog(
      context: context,
      builder: (context) =>
          DisplayPassword(password));




    class DisplayPassword extends StatelessWidget {
      var password; // check if null
      DisplayPassword(this.password); // constructor
    
      @override
      Widget build(BuildContext context) {
        // make sure null value isn't being passed to alert dialog widget
        if (password == null) {
          password = 'null value error';
        }
    
        return AlertDialog(
          title: Text(password),
        );
      }
    }



exports.getRandomPassword = functions.https.onCall(async (data, context) => {
  const useSymbols = data.useSymbols;
  const pwLength= data.pwLength;
  let password;
  password = await callAPI(pwLength,useSymbols);

  const debug ={
    received_data_type: typeof data,
    received_data:data,
    pwLen_type: typeof pwLength,
    pwLength,
    useSymbols_type:typeof useSymbols,
    useSymbols,
    ResultingPayloadType: typeof password,
    ResultingPayload: password,

  }

  console.log(debug);

  return Promise.resolve(password)

});


async function callAPI(pwLength: any, useSymbols: any) {
  // BUILD URL STRING WITH PARAMS
  const ROOT_URL = `http://[My_Api_IP_Address]/password?pwd_length=${pwLength}&use_symbols=${useSymbols}`;

  const res = await http.get(ROOT_URL);
  console.log(res.getBody());
  return res.getBody() as Map<String , any>;

}



exports.getRandomPassword=functions.https.onCall（异步（数据、上下文）=>{
const usesymbles=data.usesymbles；
const pwLength=data.pwLength；
输入密码；
密码=等待调用API（pwLength，useSymbers）；
常量调试={
接收数据类型：数据类型，
接收到的数据：数据，
pwLen_类型：pwLength的类型，
pwLength，
使用符号类型：使用符号的类型，
使用符号，
ResultingPayloadType:密码类型，
结果有效负载：密码，
}
日志（调试）；
返回承诺。解析（密码）
});
异步函数callAPI（pwLength:any，useSymbers:any）{
//使用参数生成URL字符串
const ROOT_URL=`http://[My_Api_IP_Address]/password？pwd_length=${pwdlength}&use_symbols=${usesymmbols}`；
const res=wait http.get（ROOT\u URL）；
log（res.getBody（））；
返回res.getBody（）作为映射；
}
也许我因为文章太长而错过了它，但问题是什么？什么不起作用？正如标题所示，云函数返回null。我将更新问题，以便更好地解释这一点。