在 rxjs 6 中转换 rxjs 运算符

Question

我有以下用 rxjs5 编写的代码，但它与 rxjs6 中断了

有人可以帮我写 rxjs 6

它失败的mergemap接收groupedObserable，它没有count方法和filter方法也不存在。

list [

{id: '1', type: 't1',  name: 'f1', des:'d1', selected: true},
{id: '2', type: 't1',  name: 'f2', des:'d2', selected: false},

{id: '3', type: 't1',  name: 'f11', des:'d11', selected: false},
{id: '4', type: 't1',  name: 'f22', des:'d22', selected: true},
]

Observable.from(list)
.filter(a => a.name != null)
.groupBy(i => i.type)
.mergeMap(list => {
let count = list.count;
let selectedCount = 0;
list.filter( f => f.selected).count.subscribe(c => selectedCount = c)
return count.map(count =>  {
   {
     key: list.key,
     totalCount: count,
     selected: selectedCount
   }
}
}).reduce((x, y) => {
x.isValid = x.selectedCount > 0 
return x;
}).subscribe(r => {
  console.log(r + 'any item selected')
}
)

当我尝试在 rxjs6 中编写时，我只能取得进展，直到这里 提前致谢。

from(list)
    .pipe(
    filter( s=> s.name != null) ,
    groupBy(i => i.type),
    mergeMap( (value, index) => {
      value.count // that's where it starts to fail
    }
    ))

Answer 1

等效的rxjs6代码应该是这样的：

from(list)
      .pipe(
        filter(a => a.name != null),
        groupBy(i => i.type),
        mergeMap((p) => {
          return p.pipe(
                    filter(f => f.selected),
                    count(),
                    mergeMap(c => {
                      return p.pipe(
                        count(),
                        map(totalCount => {
                          return {
                            key: p.key,
                            totalCount: totalCount,
                            selected: c
                          };
                        })
                      );
                    })
                );
        }),
        reduce((x, y) => {
          //please adjust your code here as i could not see isValid on x
          x.isValid = x.selectedCount > 0; 
          return x;
         })
      ).subscribe(r => {
        console.log(r + 'any item selected')
      }
      )

希望它能提供一个关于如何进行的想法。