订阅switchMap RXJS

Question

我在下面的代码中发现2个语法错误：

handleTypeahead = (text$: Observable<string>) => {
    text$.pipe(
      distinctUntilChanged(),
      debounceTime(500),
      .tap((term) => this.target = text$),
    // tap((term) => console.log("handleTypeahead", term)),
    // tap((term) => this.onTypeahead.emit(term)),
    /*map((term: string) => [])*/
    /*map((term: string) => term === '' ? [] : this.data)*/
    .switchMap(term => term === '' ? [] : this.data)
  ).subscribe((term) => this.onTypeahead.emit(term))

  }

1)by debounceTime -“期望的表达式”。2)by .subscribe -“未解析的函数或方法subscribe()”我在没有使用pipe操作符的情况下尝试了这一点，但也有语法错误，这是RXJS的新手，但在正确实现这一点上有很多问题。v2：

handleTypeahead = (text$: Observable<string>) => {
    text$
      distinctUntilChanged(),
    debounceTime(500),
      .tap((term) => this.target = text$),
    // tap((term) => console.log("handleTypeahead", term)),
    // tap((term) => this.onTypeahead.emit(term)),
    /*map((term: string) => [])*/
    /*map((term: string) => term === '' ? [] : this.data)*/
    .switchMap(term => term === '' ? [] : this.data)
      .subscribe((term) => this.onTypeahead.emit(term))
  }

在这里我得到了just error num#2任何感谢的帮助(当然会向上投票)

Answer 1

在.tap和.switchMap正常工作之前删除这些点：

text$.pipe(
  distinctUntilChanged(),
  debounceTime(500),
  tap(term => this.target = text$),
  switchMap(term => term === '' ? [] : this.data)
).subscribe(term => this.onTypeahead.emit(term));