How to fix member Event from @ionic/angular error in Ionic 5

Question

I have upgraded from Ionic 4 to Ionic 5, now getting following error:

ERROR in src/app/app.component.ts(4,10): error TS2305: Module '"/node_modules/@ionic/angular/ionic-angular"' has no exported member 'Events'.

Following import line is causing the issue:

import { Events, Platform } from '@ionic/angular';

How can I fix member Event from @ionic/angular error in Ionic 5?

Solution 1

Events from @ionic/angular package got removed from Ionic 5. You can see the breaking changes in Ionic5 here.

As it's mentioned in the breaking changes, you should use Observables.

For example, you can create the following service:

import {Injectable} from '@angular/core';
import {Subject} from 'rxjs';

@Injectable({
    providedIn: 'root'
})
export class GlobalFooService {

    private fooSubject = new Subject<any>();

    publishSomeData(data: any) {
        this.fooSubject.next(data);
    }

    getObservable(): Subject<any> {
        return this.fooSubject;
    }
}

Now, you can subscribe in any component like app.component.ts:

@Component({
    selector: 'app-root',
    templateUrl: 'app.component.html',
    styleUrls: ['app.component.scss']
})
export class AppComponent {

    constructor(private globalFooService: GlobalFooService) {
        this.initializeApp();
    }

    initializeApp() {
        // other code

        this.globalFooService.getObservable().subscribe((data) => {
            console.log('Data received', data);
        });
    }
}

Now, you just have to emit the event from some other component:

@Component({
    selector: 'app-home',
    templateUrl: 'home.page.html',
    styleUrls: ['home.page.scss']
})
export class HomePage {

    constructor(private globalFooService: GlobalFooService) {
    }

    onSomeButtonClick() {
        this.globalFooService.publishSomeData({
            foo: 'bar'
        });
    }
}

This is a very simple solution/example or alternative of the Events but you can tweak your code further to make it a namespaced event with a topic.

I have written a blog on this which can give you a full-featured solution so that with very less code change, you can upgrade your app.

https://medium.com/wizpanda/dealing-with-breaking-change-in-ionic-5-db3ba711dfcd

Solution 2

Events have been removed. You can do your own service as event as your own using observables,and subject behavior so you could publish to the ovserable and subscribe to get the value.

Comments

[Guilherme Sampaio]

thanks for your medium post! Used it for the migration! It would be useful if it could handle the unsubscribes, but it's great anyways! Best regards!

[Shashank Agrawal]

Hi, @GuilhermeSampaio I'm glad that the answer & the blog was useful to you. Regarding the unsubscribe, it's already there. Please look at it again gist.github.com/sagrawal31/…

[Guilherme Sampaio]

i was not clear! I was talking about unsubscribing using the string that subscribed it! I have modified my code to do it in the components using your events service! :D