Question

我想用canDeactivate中的Alertify确认替换经典确认。我尝试实现以下代码，但是单击“确定”时它不会返回True。有人可以建议吗？

import { Injectable } from '@angular/core';
import { CanDeactivate } from '@angular/router';
import { SignupComponent } from 'src/app/signup/signup.component';
import { AlertifyService } from 'src/app/_helpers/alertify.service';

@Injectable()
export class SignUpPUS implements CanDeactivate <SignupComponent> {

constructor(private alertifyService: AlertifyService) {}

canDeactivate(component: SignupComponent) {
    if (component.signUpForm.dirty) {

         this.alertifyService.confirm('Leave Page', 'Are you sure you want to continue? Any unsaved changes will be lost', () => {
            return true;
        });

    }
    return false;
}

}

Answer 1

confirm执行异步操作时，您需要使用Observable，Promise或async/await之类的异步解决方案。

您可以按以下方式使用Observable：

canDeactivate(component: SignupComponent) {
    return new Observable((observer) => {

        if (component.signUpForm.dirty) {

             this.alertifyService.confirm('Leave Page', 'Are you sure you want to continue? Any unsaved changes will be lost', 
               () => {
                 observer.next(true);
               },
               () => {
                 observer.next(false);
               }
             );
        }else{
           observer.next(false);
        }

        observer.complete();
    });

}

编辑注意：请注意，我为confirm添加了第二个回调，以确保当用户取消确认时返回false。

Answer 2

我必须进行一些细微的更改才能使其正常工作...但是接近@Harun Yimaz的答案。

AlertifyService.ts

import * as alertify from 'alertifyjs';

  confirmCancel(
    message: string,
    okCallback: () => any,
    cancelCallback: () => any
  ) {
    alertify.confirm(message, okCallback, cancelCallback);
  }

guard.ts

constructor(private alertify: AlertifyService) {}

canDeactivate(component: MemberEditComponent) {
    return new Observable<boolean>(observer => {
      if (component.editForm.dirty) {
        this.alertify.confirmCancel(
          'Are you sure you want to continue? Any unsaved changes will be lost',
          () => {
            observer.next(true);
            observer.complete();
          },
          () => {
            observer.next(false);
            observer.complete();
          }
        );
      } else {
        observer.next(true);
        observer.complete();
      }
    });

必须在下一个之后调用observer.complete（），以确保可观察性正确完成。

将Alertify与canDeactivate一起使用

2 个答案: