RxJs-具有可观察属性的FlatMap对象

Question

我正在努力处理一个简单的RxJs查询，但我似乎无法理解。如果观察对象被包装在一个对象中，我似乎不知道如何合并它们。如果我直接从flatMap返回Observable，那么这个示例可以正常工作，但我还需要在输出中输入名称。我怎样才能做到这一点？

我正在使用RxJS 5.0.0-beta.2

基本数据结构：

var data = [
  {
    "name": "Test #1",
    "users": [
      {
        "name": "John Doe",
        "gender": "male"
      },
      {
        "name": "John Doe",
        "gender": "male"
      },
      {
        "name": "Jane Doe",
        "gender": "female"
      }
    ]
  },
  {
    "name": "Test #2",
    "users": [
      {
        "name": "John Doe",
        "gender": "male"
      },
      {
        "name": "Jane Doe",
        "gender": "female"
      },
      {
        "name": "Jane Doe",
        "gender": "female"
      }
    ] 
  }
];

RxJs函数：

Observable.fromArray(data)
  .flatMap(x => {
    return Observable.of({
      "name": x.name, 
      "count": Observable.fromArray(x.users)
                .filter(x => x.gender == "male")
                .count()
      })
  })
  .toArray()
  .subscribe(result => {
    console.log(result);
  });

预期结果：

result = [
    {
      "name": "Test #1",
      "count": 2
    },
    {
      "name": "Test #2",
      "count": 1
    }
  ];

实际结果：

result = [
    {
      "name": "Test #1",
      "count": Observable
    },
    {
      "name": "Test #2",
      "count": Observable
    }
  ];

Answer 1

Observable.fromArray(data)
.flatMap(x => {
  return Observable.of({
    "name": x.name, 
    "count": x.users
              .filter(x => x.gender == "male")
              .length
  });
})
.toArray()
.subscribe(result => {
  console.log(result);
});