NgOnInit called on every route change

@charlesbronson wrote:

Hello everyone,

I have a problem with routing in my app. I tought that in Ionic on every route change, components are not being rerendered and ngOnInit is only called once. I was suprised that my components are initializing every time on route change…

that’s my package.json

{
  "name": "carin",
  "version": "0.0.1",
  "author": "Ionic Framework",
  "homepage": "https://ionicframework.com/",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/common": "~8.2.14",
    "@angular/core": "~8.2.14",
    "@angular/forms": "~8.2.14",
    "@angular/platform-browser": "~8.2.14",
    "@angular/platform-browser-dynamic": "~8.2.14",
    "@angular/router": "~8.2.14",
    "@capacitor/android": "^2.1.0",
    "@capacitor/core": "2.1.0",
    "@ionic-native/app-launcher": "^5.25.0",
    "@ionic-native/core": "^5.0.0",
    "@ionic-native/file": "^5.23.0",
    "@ionic-native/google-maps": "^5.5.0",
    "@ionic-native/in-app-browser": "^5.25.0",
    "@ionic-native/media": "^5.25.0",
    "@ionic-native/splash-screen": "^5.0.0",
    "@ionic-native/status-bar": "^5.0.0",
    "@ionic/angular": "^5.0.0",
    "cordova-android": "^8.1.0",
    "cordova-browser": "6.0.0",
    "cordova-plugin-app-launcher": "^0.4.0",
    "cordova-plugin-applist2": "^1.0.2-dev",
    "cordova-plugin-file": "^6.0.2",
    "cordova-plugin-filepath": "^1.5.8",
    "cordova-plugin-googlemaps": "git+https://github.com/mapsplugin/cordova-plugin-googlemaps.git#multiple_maps",
    "cordova-plugin-inappbrowser": "^3.2.0",
    "cordova-plugin-media": "^5.0.3",
    "core-js": "^2.5.4",
    "howler": "^2.1.3",
    "ng-circle-progress": "^1.5.1",
    "rxjs": "~6.5.1",
    "tslib": "^1.9.0",
    "wavesurfer.js": "^3.3.3",
    "zone.js": "~0.9.1"
  },
  "resolutions": {
    "@babel/preset-env": "^7.8.7"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~0.803.20",
    "@angular/cli": "~8.3.23",
    "@angular/compiler": "~8.2.14",
    "@angular/compiler-cli": "~8.2.14",
    "@angular/language-service": "~8.2.14",
    "@capacitor/cli": "2.1.0",
    "@ionic/angular-toolkit": "^2.1.1",
    "@ionic/lab": "3.1.2",
    "@types/jasmine": "~3.3.8",
    "@types/jasminewd2": "~2.0.3",
    "@types/node": "~8.9.4",
    "codelyzer": "^5.0.0",
    "cordova-plugin-device": "^2.0.2",
    "cordova-plugin-ionic-keyboard": "^2.2.0",
    "cordova-plugin-ionic-webview": "^4.1.3",
    "cordova-plugin-splashscreen": "^5.0.2",
    "cordova-plugin-statusbar": "^2.4.2",
    "cordova-plugin-whitelist": "^1.3.3",
    "jasmine-core": "~3.4.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~4.1.0",
    "karma-chrome-launcher": "~2.2.0",
    "karma-coverage-istanbul-reporter": "~2.0.1",
    "karma-jasmine": "~2.0.1",
    "karma-jasmine-html-reporter": "^1.4.0",
    "npm-force-resolutions": "0.0.3",
    "protractor": "~5.4.0",
    "ts-node": "~7.0.0",
    "tslint": "~5.15.0",
    "typescript": "~3.4.3"
  },
  "description": "An Ionic project",
  "cordova": {
    "plugins": {
      "cordova-plugin-whitelist": {},
      "cordova-plugin-statusbar": {},
      "cordova-plugin-device": {},
      "cordova-plugin-splashscreen": {},
      "cordova-plugin-ionic-webview": {
        "ANDROID_SUPPORT_ANNOTATIONS_VERSION": "27.+"
      },
      "cordova-plugin-ionic-keyboard": {},
      "cordova-plugin-googlemaps": {},
      "cordova-plugin-file": {},
      "cordova-plugin-filepath": {},
      "cordova-plugin-applist2": {},
      "cordova-plugin-app-launcher": {},
      "cordova-plugin-inappbrowser": {},
      "cordova-plugin-media": {}
    },
    "platforms": [
      "browser",
      "android"
    ]
  }
}

routing.module.ts

import { NgModule } from '@angular/core';
import { PreloadAllModules, RouterModule, Routes } from '@angular/router';

const routes: Routes = [
  { path: '', redirectTo: 'home', pathMatch: 'full' },
  { path: 'home', loadChildren: () => import('./home/home.module').then( m => m.HomePageModule)},
  { path: 'media', loadChildren: () => import('./media/media.module').then( m => m.MediaModule)},
  { path: 'apps', loadChildren: () => import('./apps/apps.module').then( m => m.AppsModule)},
  {
    path: 'test',
    loadChildren: () => import('./test/test.module').then( m => m.TestPageModule)
  },
];

@NgModule({
  imports: [
    RouterModule.forRoot(routes, { preloadingStrategy: PreloadAllModules })
  ],
  exports: [RouterModule]
})
export class AppRoutingModule { }

and for example AppsRoutingModule:

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { AppsPage } from './apps.page';


const routes: Routes = [
  {
    path: '',
    component: AppsPage
  }
];

@NgModule({
  imports: [RouterModule.forChild(routes)],
  exports: [RouterModule]
})
export class AppsRoutingModule { }

I have noticed that when eg. /home page is the first loaded page and then i switched to /apps and switched back to /home, the home is not initializing multiple times, but when i switch back again to /apps, apps are initializing again.

In AppModule I have provider Routes strategy like that:

    providers: [
        StatusBar,
        SplashScreen,
        {provide: RouteReuseStrategy, useClass: IonicRouteStrategy},
    ],

Does anyone have an idea what’s going wrong?

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