如何从 Firebase Cloud Functions 中调用 Google Places API？

Question

我正在尝试借助 Google Places API 及其自动完成功能在我的 Flutter 应用中实现位置自动完成功能。为了使 API 调用逻辑和 API 密钥远离客户端，Flutter App 应该调用 Firebase Cloud Function，然后调用 Google Places API。我一直试图让这个工作好几天，通过各种文章工作，我就是无法取得任何进展。这是我的 Firebase Cloud Function 的源代码：

import * as functions from "firebase-functions";
import * as axios from "axios";

export const autofillSuggestions = functions.region("europe-west3")
    .https.onCall(async (data) => {
      const input = data.input;
      const sessionToken = data.sessiontoken;

      // will be stored as an environment variable, as soon as i get cloud function to work
      const googleAPIKey = "my_api_key"; 
      

      const requestURL = "https://maps.googleapis.com/maps/api/place/autocomplete/json?input=" + input +
     "&key=" + googleAPIKey + "&sessiontoken=" + sessionToken;

      return await axios.default.get(requestURL).then((apiResponse) => {
        return {predictions: apiResponse.data.predictions,
        };
      })
          .catch((error) => {
            console.log(error);
          });
    });

这个源代码被导入到index.ts，然后再次导出文件，所以问题不应该存在。 Flutter App 内部的云函数调用逻辑如下所示：

HttpsCallable _getCallable(String functionName) =>
      FirebaseFunctions.instance.httpsCallable(functionName);

 Future<dynamic> _getSuggestionsFromGoogleMapsAPI(String input) async {
    //FirebaseFunctions.instance
    //    .useFunctionsEmulator(origin: 'http://localhost:5001');
    final callable = _getCallable('autofillSuggestions');

    try {

      final data = HashMap.of({
        'sugg': input,
        'sessionToken': _sessionToken,
      });
      final response = await callable.call(data);
      return response.data;
    } catch (e) {
      print(e);
      throw AutocompletionFailure();
    }
  }

当我在 Flutter 应用程序中触发 Cloud Function Call 并取消注释提到 useFunctionsEmulator 的行时，一切正常。但是一旦我再次注释掉这些并想与真正的 Firebase 服务器通信，我总是在 VS Code 调试控制台中收到此错误消息：

[firebase_functions/internal] Response is not valid JSON object.

Firebase 服务器上的错误日志如下所示：

autofillSuggestions
{
 "@type":"type.googleapis.com/google.cloud.audit.AuditLog",
 "authenticationInfo":{"principalEmail":"my@mail.com"},
 "requestMetadata": 
   {
     "callerIp":"10.10.101.101",
     "callerSuppliedUserAgent":"FirebaseCLI/9.8.0,gzip(gfe),gzip(gfe)",
     "requestAttributes":{"time":"2021-04-04T09:34:15.120516Z","auth":{}},
     "destinationAttributes":{}
   },
 "serviceName":"cloudfunctions.googleapis.com",
 "methodName":"google.cloud.functions.v1.CloudFunctionsService.SetIamPolicy",
 "authorizationInfo":
   [
    {
     "resource":"projects/my-project/locations/europe-west3/functions/autofillSuggestions",
     "permission":"cloudfunctions.functions.setIamPolicy",
     "granted":true,
     "resourceAttributes":{}
    },
    {
     "permission":"cloudfunctions.functions.setIamPolicy",
     "granted":true,
     "resourceAttributes":{}
    }
   ],
 "resourceName":"projects/my-project/locations/europe-west3/functions/autofillSuggestions",
 "request":
   {
    "updateMask":"version,bindings",
    "resource":"projects/my-project/locations/europe-west3/functions/autofillSuggestions",
    "policy":
      {
       "bindings":
         [
          {
           "members":["allUsers"],
           "role":"roles/cloudfunctions.invoker"
          }
         ]
      },
    "@type":"type.googleapis.com/google.iam.v1.SetIamPolicyRequest"
   },
 "response":
   {
    "bindings":
        [
         {
          "members":["allUsers"],
          "role":"roles/cloudfunctions.invoker"
         }
        ],
    "@type":"type.googleapis.com/google.iam.v1.Policy","etag":"BwW/IkjRmog="
   },
 "resourceLocation":{"currentLocations":["europe-west3"]}
}

由于它没有提及Function execution started 或Function execution terminated with ... 之类的内容，我怀疑根本没有调用云函数...我的想法是否正确？如果是的话，有谁知道如何让它工作？？？

我非常关注this 和this article。我还发现this 很有趣，但还没有尝试过，因为我认为我的主要问题是云函数甚至没有被调用......

Answer 1

答案是 - 当然 - 非常愚蠢，但我想这是 IT 和自学成才的诅咒...... 如您所见，由于我的位置，我将europe-west3 指定为我的云函数的区域。但是在获取callable引用时，我没有指定区域，导致cloud_functionsflutter包创建了一个FirebaseFunctions实例，默认区域设置为us-central1。这弄乱了通话并导致了内部错误。简单的解决方法是在颤振应用程序中：

_getCallable 的新实现：

HttpsCallable _getCallable(String functionName) {
   return FirebaseFunctions.instanceFor(region: 'europe-west3')
       .httpsCallable(functionName);
}