Question

使用angular js处理对话框组件，现在我发现我的函数已订阅，并且如果条件不退出方法，而是连续执行另一个函数afterClosed()，这是代码示例：

openCreateNewContentDialog(): void {
    const oldData = this.dataSource.data;
    const dialogConfig = AppConstants.matDialogConfig();
    const dialog = this.dialog.open(LicenseDialogComponent, dialogConfig);

    dialog.beforeClosed().subscribe(licenceDate => {
      for (const datesToCheck of oldData) {
        const newDateFrom = new Date(licenceDate.expirationDateFrom);
        const oldDateTo = new Date(datesToCheck.expirationDateTo.toString());
        if (newDateFrom <= oldDateTo) {
          // console.log('return?');
          return;
        }
      }
    });

    dialog.afterClosed().subscribe(licence => {
      if (licence) {
        this._value.push(licence);
        this.dataSource.data = this.value;
        this.change();
      }
    });
  }

退订beforeClosed()函数的最佳方式是什么？

Answer 1

因此，根据您的描述，我了解到您t want a second subscription to happen if the condition in the first subscriber is true, right? But you subscription will happen anyway because you instantiated it in the method, the code in the subscribe() it's just a callback. So if you don不需要大量重写，我建议您存储变量中的订阅，因此您可以访问它们并且可以随时取消订阅。

openCreateNewContentDialog(): void {
const oldData = this.dataSource.data;
const dialogConfig = AppConstants.matDialogConfig();
const dialog = this.dialog.open(LicenseDialogComponent, dialogConfig);

const beforeClosed = dialog.beforeClosed().subscribe(licenceDate => {
  for (const datesToCheck of oldData) {
    const newDateFrom = new Date(licenceDate.expirationDateFrom);
    const oldDateTo = new Date(datesToCheck.expirationDateTo.toString());
    if (newDateFrom <= oldDateTo) {
      // console.log('return?');
      afterClosed.unsubscribe();
      return;
    }
  }
});

const afterClosed = dialog.afterClosed().subscribe(licence => {
  if (licence) {
    this._value.push(licence);
    this.dataSource.data = this.value;
    this.change();
  }
});

}

希望对您有所帮助！如果必须处理多个订阅，也可以尝试https://www.digitalocean.com/community/tutorials/angular-takeuntil-rxjs-unsubscribe。

如何退订方法中的功能？

1 个答案: