javascript - switchMap 操作只在第一次调用时运行？

Question

我有一个 Angular 应用程序，它向 Http 服务发出请求并在另一个 Http 服务上调用 switchMap。由于某种原因，switchMap 中的请求仅在第一次调用父调用时运行。否则父请求会触发而 switchMap 不会，这里是代码:

this._receivableService.newTenantDebitCredit(tenantCredit)
            .take(1)
            .switchMap(result =>
                // Refresh the lease receivables before giving result
                this._receivableService.getAll({
                    refresh: true,
                    where: { leaseId: this.leaseId }
                }).take(1).map(() => result)
            )
            .subscribe(
                ...
            )

每次在其上方调用 newTenantDebitCredit 方法时，如何使切换映射中的 getAll 请求运行？

编辑:这是在单击 时调用的完整函数。当我第一次单击给定单元的按钮时，两种方法都会执行。如果我尝试一个已经调用了该方法的单元(没有刷新)，则只执行第一个方法。我意识到其中很多内容可能还不清楚，目前这是一个相当大的项目。

public submitTenantCredit() {
        this.isLoading = true;
        let tenantCredit: NewTenantDebitCreditData;
        let receivableDefinitions: ReceivableDefinition[] = [];

        // construct receivable defintions for NewTenantDebitData model
        receivableDefinitions = this._constructReceivableDefinitions();

        // construct data we will be POSTing to server.
        tenantCredit = new NewTenantDebitCreditData({
            siteId: this._apiConfig.siteId,
            leaseId: this.leaseId,
            isCredit: true,
            receivables: receivableDefinitions,
            reason: this.actionReason
        });

        // make service call and handle response
        this._receivableService.newTenantDebitCredit(tenantCredit)
            .take(1)
            .switchMap(result =>
                // Refresh the lease receivables before giving result
                this._receivableService.getAll({
                    refresh: true,
                    where: { leaseId: this.leaseId }
                }).take(1).map(() => result)
        )
            .take(1)
            .subscribe(
                (receivables) => {
                    this.closeReasonModal();
                    let refreshLeaseId = this.leaseId;
                    this.leaseId = refreshLeaseId;
                    this.isLoading = false;
                    this.refreshBool = !this.refreshBool;
                    this._debitCreditService.refreshUnitInfo();
                    this._notifications.success(`The tenant credit for ${this.customerName} - Unit ${this.unitNumber} was submitted successfully`);
                },
                (error) => {
                    console.error(error);
                    this.isLoading = false;
                }
            )
    }

如果有帮助 newTenantDebitCredit() 是一个 HTTP POST 请求并且 getAll() 是一个 GET 请求.

Answer 1

您使用了 take 运算符。当您的服务 observable 将发出时，take 运算符将首先执行，而 take 将仅首先从 observable 发出。随后的发射将不会被您的代码占用。如果你想从 observable 中获取所有发射，那么从你的代码中删除 take。

希望对您有所帮助。