Resize / DOM Events / "Style change" triggers ngif?

@Rotestasd wrote:

I noticed some major performance issues in my ionic project, so i checked what was going on, and found out that my *ngIf is triggered every time i click somewhere or the window is resized. I setup a new clean ionic project and it also seems to happen there. I re-created the same scenario in a blank angular project without ionic, and it doesn’t happen there, so it might be an ionic-only issue.

Sample Code:
app.component.html

<div *ngIf="test()"></div>

app.component.ts:

@Component({
  selector: 'app-root',
  templateUrl: 'app.component.html'
})
export class AppComponent {
  constructor(
    private platform: Platform,
    private splashScreen: SplashScreen,
    private statusBar: StatusBar
  ) {
    this.initializeApp();
  }

  initializeApp() {
    this.platform.ready().then(() => {
      this.statusBar.styleDefault();
      this.splashScreen.hide();
    });
  }

  test(){
    console.log('change');
  }
}

04-07-_2019_10-09-38.png1131×140 6.29 KB

This is the browsers output, notice that the log message was called 180+ times after resizing the window…
What is the issue here? Is it a bug? Is it expected behavior? It doesn’t seem to happen in a blank angular project.

I read some things about using changeDetection with OnPush, but then my Observables and BehaviorSubjects from my Services aren’t working anymore

Ionic Version:
Ionic CLI : 5.0.0 (C:\Users\admin\AppData\Roaming\npm\node_modules\ionic)
Ionic Framework : @ionic/angular 4.4.2
@angular-devkit/build-angular : 0.13.9
@angular-devkit/schematics : 7.3.9
@angular/cli : 7.3.9
@ionic/angular-toolkit : 1.5.1

Posts: 1

Participants: 1

Read full topic