Switchmap 返回单个字符 - Angular

Question

如果满足条件，我尝试从 switchmap 返回一个值，但它返回的 console.log 被分解为单个字符。因此，如果角色返回为买家，那么它就会返回为

console.log("RES");
console.log(res);

输出

RES
B
RES
u
RES
y
RES
e
RES
r

如何从 中返回完整的值subscribe()？我真的不明白为什么它会打破它。我很感激任何帮助！

邀请组件.ts

...
   const linkExpiredDate = new Date(date);
          const invite = new SendInvite();
          invite.inviteEmail = form.value.email;
          invite.invitedBy = this.userId;
          invite.inviteLinkExpirationDate = linkExpiredDate;

          this.inviteService
            .sendInvite(invite)
            .pipe(takeUntil(this.destroy))
            .subscribe(
              res => {

                console.log("RES");
                console.log(res);

                this.timeout = this.toastr.success("Invite sent!", "", {
                  timeOut: 2000
                });

                this.invites.push({
                  inviteEmail: form.value.email,
                  invitedBy: this.userId,
                  inviteDate: Date.now()
                });

                this.dataSource.data = this.invites;
              },
              error => {

                console.log(error)
                this.timeout = this.toastr.warning(
                  "This user is already a member!",
                  "",
                  {
                    timeOut: 2000
                  }
                );
                return;
              }
            );
        }

邀请服务.ts

 sendInvite(inviteRequest: SendInvite) {
    console.log("INVITED BY" + inviteRequest.invitedBy);
    const invite: SendInvite = {
      id: null,
      inviteEmail: inviteRequest.inviteEmail,
      invitedBy: inviteRequest.invitedBy,
      inviteLinkExpirationDate: inviteRequest.inviteLinkExpirationDate
    };
    return this.validateEmail(invite.inviteEmail).pipe(
      switchMap(emails => {

        if (emails.message === "User found" && emails.role === "Artist") {
          this.toastr.warning("User already has a Seller Account", "", {
            timeOut: 6000
          });
          return emails.role;
        }
        if (emails.message === "User found" && emails.role === "Buyer") {
          this.toastr.warning("User already has a Buyer Account. Use different email or upgrade Buyer Account", "", {
            timeOut: 6000
          });
          return emails.role;
        } else {
          console.log("EMAIL MESSAGE " + emails.message);

          console.log("USER NOT FOUND!");
          return this.http.post<{
            messageId: string;
            inviteId: string;
            creator: string;
          }>(environment.azure_function_url + "/POST-Artist-Invites", invite);
        }
      })
    );
  }

Answer 1

您正在返回stringswitchMap 函数内部。字符串是字符数组。RxJS 将数组视为事件流（有时使用诸如 之类的运算符switchMap，更具体地说是在可以传递 的任何地方ObservableLike）。所以你得到的是一个角色事件流，它被合并到你的外部可观察中。因此你的控制台输出。

我想你可能想要的是将你包装emails.role成一个of运算符，这样你就得到了return of(emails.role)。

of使用您提供的值发出单个事件，而不是尝试将该值解释为 Observable 流。