Ionic5: setting a footer on all app pages with a sharedModule and controlling it (on/off) from the app.component

Question

I've created a new app using Ionic5 with a menu. I'm trying to use a Footer on multiple pages (now only on Home page). First I've created a SharedModule and imported in the imports' array of the app.module.ts. I've added the footer component in the declarations' and exports' array of the shared.module.ts. Also I added SharedModule in the imports' array of each page.module.ts, and finally adding <app-footer> in each page.html. It works as expected, showing the footer in all pages. But now I need to control (on/off) this footer from my app.component, in response to a specific event, for example, when internet is not available (this part is not a problem).

footer.component.ts

import { Component, OnInit } from '@angular/core';
import { FooterService } from 'src/app/footer.service';
@Component({
  selector: 'app-footer',
  templateUrl: './footer.component.html',
  styleUrls: ['./footer.component.scss'],
})
export class FooterComponent implements OnInit {

  public FooterEnabled: boolean= false;

  constructor() { }
  ngOnInit() {
  }
}

The FooterEnabled variable control if the footer is showed or not and must be modifiable from the app.component

footer.component.html

<div class="footer-conn" *ngIf="FooterEnabled">
    Alert!
</div>

sharedfooter.module.ts

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FooterComponent } from '../components/footer/footer.component';

@NgModule({
  declarations: [FooterComponent],
  imports: [
    CommonModule
  ],
  exports: [
    FooterComponent, CommonModule
  ]
})
export class SharedFooterModule { }

app.module.ts

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { RouteReuseStrategy } from '@angular/router';

import { IonicModule, IonicRouteStrategy } from '@ionic/angular';
import { SplashScreen } from '@ionic-native/splash-screen/ngx';
import { StatusBar } from '@ionic-native/status-bar/ngx';

import { AppComponent } from './app.component';
import { AppRoutingModule } from './app-routing.module';
import { Network } from '@ionic-native/network/ngx';

import { SharedFooterModule } from './shared/sharedfooter.module';

@NgModule({
  declarations: [AppComponent],
  entryComponents: [],
  imports: [
    BrowserModule,
    IonicModule.forRoot(),
    AppRoutingModule,
    SharedFooterModule
  ],
  providers: [
    StatusBar,
    SplashScreen,
    Network,
    
    { provide: RouteReuseStrategy, useClass: IonicRouteStrategy }
  ],
  bootstrap: [AppComponent]
})
export class AppModule {}

app.component.ts

import { Component, OnInit } from '@angular/core';
import { Platform } from '@ionic/angular';
import { SplashScreen } from '@ionic-native/splash-screen/ngx';
import { StatusBar } from '@ionic-native/status-bar/ngx';
import { Network } from '@ionic-native/network/ngx';

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

export class AppComponent implements OnInit {

  public selectedIndex = 0;
  public appPages = [
    {
      title: 'Página 1',
      url: 'home',
      icon: 'mail'
    }, 
    {
      title: 'Página 2',
      url: 'pagina2',
      icon: 'paper-plane'
    },
    {
      title: 'Página 3',
      url: 'pagina3',
      icon: 'heart'
    }
  ];  

    constructor(
    private platform: Platform,
    private splashScreen: SplashScreen,
    private statusBar: StatusBar,
    private network: Network
    ) {
      
    this.initializeApp();   
    
  }// Fin constructor

  no_internet() {
    alert("No internet!")
   // In this point make FooterEnabled = true (from the footer component)
  }

  si_internet() {
    alert("Whith internet!") 
    //In this point make FooterEnabled = false (from the footer component)
  }

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

  ngOnInit() {

    let disconnectSubscription = this.network.onDisconnect().subscribe(() => {
      setTimeout(() => {
        if (this.network.type !== 'none') {
          this.si_internet();
        }
        else {
          this.no_internet();

        }
      }, 1000);
      
    });
    // watch network for a connection
    let connectSubscription = this.network.onConnect().subscribe(() => {
      setTimeout(() => {
        if (this.network.type !== 'none') {
          this.si_internet();
        }
        else {
          this.no_internet(); 
        }
      }, 3000);
    });

    const path = window.location.pathname.split('/')[1];
    if (path !== undefined) {
      this.selectedIndex = this.appPages.findIndex(page => page.title.toLowerCase() === path.toLowerCase());
    }
  }
}

home.module.ts (as an example)

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule } from '@angular/forms';
import { IonicModule } from '@ionic/angular';
import { HomePageRoutingModule } from './home-routing.module';
import { HomePage } from './home.page';
import { SharedFooterModule } from '../shared/sharedfooter.module';

@NgModule({
  imports: [
    CommonModule,
    FormsModule,
    IonicModule,
    HomePageRoutingModule,
    SharedFooterModule
  ],
  declarations: [HomePage]
})
export class HomePageModule {}

I've tried with a service imported in the footer.component and app.component.ts that implements observables, but it didn't work. I will appreciate your contributions!!

Answer 1

maybe you can do it like bellow, add input to your footer component :

footer.component.ts

import { Component, OnInit, Input } from '@angular/core';
@Component({
  selector: 'app-footer',
  templateUrl: './footer.component.html',
  styleUrls: ['./footer.component.scss'],
})
export class FooterComponent implements OnInit {
  @Input() FooterEnabled : string;
  //public FooterEnabled: boolean= false;

  constructor() { }
  ngOnInit() {
  }
}

footer.component.ts

<div class="footer-conn" *ngIf="FooterEnabled == 'on'">
    Alert!
</div>

on your app.component.ts add new varibale status:

  no_internet() {
    alert("No internet!")
    this.status = 'on'
  }

  si_internet() {
    alert("Whith internet!") 
    this.status = 'off'
  }

put it on app.component.html as :

<app-footer FooterEnabled="status" ></app-footer>