Component is part of the declaration of 2 modules

Question

I try to build an ionic 2 app. When I try the app in the browser with ionic serve or launch it on an emulator everything works fine.

But when I try to build it every

Answer 1

To surpass this error , you should start by removing all the imports of app.module.ts and have something like this :

            import { BrowserModule } from '@angular/platform-browser';
            import { HttpClientModule } from '@angular/common/http';
            import { ErrorHandler, NgModule } from '@angular/core';
            import { IonicApp, IonicErrorHandler, IonicModule } from 'ionic-angular';
            import { SplashScreen } from '@ionic-native/splash-screen';
            import { StatusBar } from '@ionic-native/status-bar';

            import { MyApp } from './app.component';


            @NgModule({
              declarations: [
                MyApp
              ],
              imports: [
                BrowserModule,
                HttpClientModule,
                IonicModule.forRoot(MyApp)
              ],
              bootstrap: [IonicApp],
              entryComponents: [
                MyApp
              ],
              providers: [
                StatusBar,
                SplashScreen,
                {provide: ErrorHandler, useClass: IonicErrorHandler}
              ]
            })
            export class AppModule {}

Next edit your pages module , like this :

            import { NgModule } from '@angular/core';
            import { IonicPageModule } from 'ionic-angular';
            import { HomePage } from './home';

            @NgModule({
              declarations: [
                HomePage,
              ],
              imports: [
                IonicPageModule.forChild(HomePage),
              ],
              entryComponents: [HomePage]
            })
            export class HomePageModule {}

Then add annotation of IonicPage before component annotation of all the pages :

import { IonicPage } from 'ionic-angular';

@IonicPage()
@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})

Then edit your rootPage type to be string and remove the imports of pages (if there is any in your app component )

rootPage: string = 'HomePage';

Then the navigation function should be like this :

 /**
* Allow navigation to the HomePage for creating a new entry
*
* @public
* @method viewHome
* @return {None}
*/
 viewHome() : void
 {
  this.navCtrl.push('HomePage');
 }

You can find the source of this solution here : Component is part of the declaration of 2 modules