angular- programmatically close alert when a new alert is triggered

问题

I have two kinds of alerts- secondary alerts and delayed alerts Secondary alert messgaes are shown at first and user has to hit OK button to close it.

But there are delayed alerts also..which are triggered by a setTimeout() I'm trying to automatically close secondary alerts when this delayed alert is shown to user

I tried to dismiss the secondary alerts like this

this.secondaryAlertVar.dismiss();

But it's not working.

Here's the code

import { Component, OnInit } from "@angular/core";
import * as dialogs from "tns-core-modules/ui/dialogs";
@Component({
    selector: "Home",
    moduleId: module.id,
    templateUrl: "./home.component.html",
    styleUrls: ['./home.component.css']
})
export class HomeComponent implements OnInit {

    secondaryAlertVar: any;
    constructor() {
        this.secondaryAlerts(function () { }, 0, "Hhmm... ", "Alert");

        setTimeout(() => {
            this.delayedAlertBox("All other alerts should close automatically when this triggered");
        }, 10000);
    }

    ngOnInit() {
    }

    secondaryAlerts(callback, mode, message, title): any {
      this.secondaryAlertVar =  dialogs
            .alert({
                title: title,
                message: message,
                cancelable: false,
                okButtonText: "OK"
            })
            .then(callback);
    }

    delayedAlertBox(message) {
        this.secondaryAlertVar.dismiss();
        var options = {
            title: "Delayed Alert",
            message: message,
            okButtonText: "Ok",
            cancelable: false,
        };
        dialogs.alert(options).then(() => {
        });
    }
}

Playground Link

回答1:

Try this using rxjs you can achieve this.

import { Component, OnInit } from "@angular/core";
import * as dialogs from "tns-core-modules/ui/dialogs";
import { interval, timer } from 'rxjs';
import { takeUntil } from 'rxjs/operators'
@Component({
    selector: "Home",
    moduleId: module.id,
    templateUrl: "./home.component.html",
    styleUrls: ['./home.component.css']
})
export class HomeComponent implements OnInit {

      source = interval(0);
      alive = true;
      secondaryAlertVar: any;

      constructor() {

       const example = this.source.pipe(takeWhile(() => this.alive));
       const subscribe = example.subscribe(val => {
        this.secondaryAlerts(function () { }, 0, "Hhmm... ", "Alert");
       });

        setTimeout(() => {
        this.alive = false;
            this.delayedAlertBox("All other alerts should close automatically when this triggered");
        }, 10000);
    }

    ngOnInit() {
    }

    secondaryAlerts(callback, mode, message, title): any {
      this.secondaryAlertVar =  dialogs
            .alert({
                title: title,
                message: message,
                cancelable: false,
                okButtonText: "OK"
            })
            .then(callback);
    }

    delayedAlertBox(message) {
        this.secondaryAlertVar.dismiss();
        var options = {
            title: "Delayed Alert",
            message: message,
            okButtonText: "Ok",
            cancelable: false,
        };
        dialogs.alert(options).then(() => {
        });
    }
}

来源：https://stackoverflow.com/questions/58323839/angular-programmatically-close-alert-when-a-new-alert-is-triggered