NGRX 无法读取实体参数

Question

我正在尝试设置一个使用ngrx的应用程序。

当应该加载单个实体时，我很难访问返回的实体参数。

我也因无法访问实体参数而以模态形式加载实体。

首先，通过data.service

从后端调用员工列表

data.service.ts：

  getEngineers() {
return this.http.get<Engineer[]>(this.engineersUrl);
}

返回所有注册工程师。

一旦列出了所有工程师条目，Engineer-list.componenent.ts添加了EditEngineer函数：

  editEngineer(engineer: Engineer) {
this.store.dispatch(new engineerActions.LoadEngineer(engineer.id));
this.openEditDialog(engineer);
console.log(engineer.id, 'selectedEngineersId');
 }
 openEditDialog({ Name, LastName, PhoneNumber, Company, Country }: Engineer) 
{
const dialogRef = this.dialog.open(EgnineerEditDialogComponent, {
  disableClose: true,
  width: '300px',
  data: {
    Name, LastName, PhoneNumber, Company, Country
  }
 });
}

然后进行loadEngineer $（）效果：

@Effect()
loadEngineer$: Observable<Action> = this.actions$.pipe(
    ofType<engineerActions.LoadEngineer>(
        engineerActions.EngineerActionTypes.LOAD_ENGINEER
    ),
    mergeMap((action: engineerActions.LoadEngineer) =>
        this.dataService.getEngineerById(action.payload).pipe(
            map(
                (engineer: Engineer) =>
                new engineerActions.LoadEngineerSuccess(engineer)
            ),
            catchError(err => of(new engineerActions.LoadEngineerFail(err)))
        )
    ),
);

data.service呼叫getEngineerById（）：

  getEngineerById(payload: number): Observable<Engineer> {
     console.log(`${this.engineerUrl}?id=${payload}`);
      return this.http.get<Engineer>(`${this.engineerUrl}?id=${payload}`);
  }

从php mysql请求返回所选工程师的JSON响应：

$result = $conn->query($sql);
$emparray = $result->fetch_all( MYSQLI_ASSOC );
echo json_encode( $emparray );

下一步是由load_engineer_success

采取的。

        case engineersActions.EngineerActionTypes.LOAD_ENGINEER_SUCCESS: {
        console.log(action.payload.id, ' - ID of the selected engineer object');
        return engineerAdapter.addOne(action.payload, {
            ...state,
           selectedEngineerId: action.payload.id,
           loading: false,
           loaded: true
        });
    }

这里的问题是，REDUCER的控制台已记录了响应

console.log(action.payload.id, ' - ID of the selected engineer object');

返回undefined " - ID of the selected engineer object"当游戏机记录" action.payload"返回时：

[{…}]
0:
Company: "Andys Shack"
Country: "EE"
LastName: "Franklichtenshtein    "
Name: "Angus    "
PhoneNumber: "123123123123    "
Registered: "2019-03-09 01:33:28"
id: "19"
__proto__: Object
length: 1
__proto__: Array(0)

和NGRX还返回错误：

entity.js:106 @ngrx/entity: The entity passed to the `selectId` implementation returned undefined. You should probably provide your own `selectId` implementation. The entity that was passed: [{…}]0: {id: "19", Name: "Angus    ", LastName: "Franklichtenshtein    ", PhoneNumber: "123123123123    ", Country: "EE", …}length: 1__proto__: Array(0) The `selectId` implementation: function (instance) { return instance.id; }

Answer 1

有效载荷是一个数组，而不是对象。

action.payload[0].id