App cleaning data from the main page, when switching to secondary pages (IONIC 3)

I have the 'orders' page as the main one, where you have the button to select the client, and select the products.

When I click on 'select client' selectClient () method, it sends to 'select-client' page, where it is a list, selecting client, returns to 'orders' screen.

So far beauty, now comes the problem. Click on the 'select products' button, selectProduct () method,

Following codes:

orders.ts:

import { OrdersProvider, Orders } from '../../providers/orders/orders';
import { ClientProvider, Client } from '../../providers/client/client';
import { Storage } from '@ionic/storage';

import { Component } from '@angular/core';
import { IonicPage, NavController, NavParams, AlertController } from 'ionic-angular';

@IonicPage()
@Component({
selector: 'page-orders',
templateUrl: 'orders.html',
})
export class OrdersPage {

payment:  any[]     = [];
clients:  any[]     = [];
itens:    any[]     = [];
qtdItens: any       = 0;
valTotal: any       = 0;
totalST:  any       = 0;
totalIPI: any       = 0;
shownGroup: string  = null;

nomusu: string;
codven: string;
codigo: string;
razsoc: string;
dateNow: string = new Date().toISOString();

constructor(
    public navCtrl: NavController,
    public navParams: NavParams,
    private ordersProvider: OrdersProvider,
    private clientProvider: ClientProvider,
    public alertCtrl: AlertController,
    private storage: Storage) {
}

ionViewDidLoad() {
    this.getPayment();
    this.getAllClients();

    this.qtdItens = this.navParams.get('totalItens');
    this.valTotal = this.navParams.get('totalValor');
    this.totalST  = this.navParams.get('totalST');
    this.totalIPI = this.navParams.get('totalIPI');
    this.itens    = this.navParams.get('itensList');
    this.codigo   = this.navParams.get('codigo');
    this.razsoc   = this.navParams.get('razsoc');

    if(this.qtdItens == undefined) this.qtdItens = 0;
    if(this.valTotal == undefined) this.valTotal = 0;
    if(this.totalST == undefined) this.totalST = 0;
    if(this.totalIPI == undefined) this.totalIPI = 0;

    this.storage.get('nomusu').then(nomusu => {
        this.storage.get('codven').then(codven => {
            this.nomusu = nomusu;
            this.codven = codven;
        });
    });

    //console.log(this.qtdItens)
}

getPayment() {
    this.ordersProvider.getAll()
    .then((result: any[]) => {
        this.payment = result;
    });
}

getAllClients() {
    this.clientProvider.getAll('')
    .then((result: any[]) => {
        this.clients = result;
    });
}

selectProduct() {
    this.navCtrl.setRoot("SelectProductPage");
}

selectClient() {
    this.navCtrl.setRoot("SelectClientPage");
}

click() {
    this.alertCtrl.create({
        title: 'Pedido salvo!',
        subTitle: '',
        buttons: ['OK']
    }).present();
}

toggleGroup(group) {
    if (this.isGroupShown(group)) {
        this.shownGroup = null;
    } else {
        this.shownGroup = group;
    }
};

isGroupShown(group) {
    return this.shownGroup === group;
};

}

select-product.ts:

import { ProductProvider } from '../../providers/product/product';
import { Component } from '@angular/core';
import { IonicPage, NavController, NavParams, AlertController } from 'ionic-angular';
import { Product } from '../../providers/product/product';
//import { BarcodeScanner } from '@ionic-native/barcode-scanner';

@IonicPage()
@Component({
selector: 'page-select-product',
templateUrl: 'select-product.html',
})
export class SelectProductPage {
model: Product;
products: any[]    = [];
searchText: string = null;

totalItens: any = 0;
totalValor: any = 0;
totalST:    any = 0;
totalIPI:   any = 0;
totalDesc:  any = 0;

constructor(
    public navCtrl: NavController,
    public navParams: NavParams,
    private productProvider: ProductProvider,
    public alertCtrl: AlertController)
    {

    this.model = new Product();
}

ionViewDidLoad() {
    //console.log('ionViewDidLoad SelectProductPage');
    this.getAllProducts();
    this.sumQuanti('somar');
}

getAllProducts() {
    this.productProvider.getAll(this.searchText)
    .then((result: any[]) => {
        this.products = result;
    });
}

increment(item) {
    item.CON010 += 1;
}

decrement(item) {
    if(item.CON010 > 0) item.CON010 -= 1;
}

sumQuanti(tipo) {
    var sum = 0;

    this.products.forEach(function(item, index) {

        var quanti = parseInt(item.CON010, 10);
        if(isNaN(quanti)) quanti = 0;

        if(tipo == 'somar') {
            sum += quanti;
        } else {
            sum -= quanti * -1;
        }
    });

    this.totalItens = sum;

    return this.totalItens;
};

valorTotal(tipo) {
    var total = 0;

    this.products.forEach(function(item, index) {

        var quanti = parseInt(item.CON010, 10);
        if(isNaN(quanti)) quanti = 0;

        if(tipo == 'somar') {
            total += item.PRE001 * quanti;
        } else {
            total -= item.PRE001 * quanti * -1;
        }
    });

    this.totalValor = total;

    return this.totalValor;
}

valorST(tipo) {
    var st = 0;

    this.products.forEach(function(item, index) {

        var quanti = parseInt(item.CON010, 10);
        if(isNaN(quanti)) quanti = 0;

        if(tipo == 'somar') {
            st += item.PRE001 * quanti * 1.5;
        } else {
            st += item.PRE001 * quanti * 1.5 * -1;
        }

    });

    this.totalST = st;

    return this.totalST;
}

valorIPI(tipo) {
    var ipi = 0;

    this.products.forEach(function(item, index) {

        var quanti = parseInt(item.CON010, 10);
        if(isNaN(quanti)) quanti = 0;

        if(tipo == 'somar') {
            ipi += item.PRE001 * quanti * 10 / 100;
        } else {
            ipi += item.PRE001 * quanti * 10 / 100 * -1;
        }
    });

    this.totalIPI = ipi;

    return this.totalIPI;
}

filterProducts(ev: any) {
    this.getAllProducts();
}

scanProduct() {
/*    this.barcodeScanner.scan().then(barcodeData => {
        console.log(JSON.stringify(barcodeData))
    }).catch(err => {
        console.log('Error', err);
    });*/
}

saveItens() {
    var itens: any[] = [];

    for (var i = 0; i < this.products.length; i++) {
        var item = this.products[i];

        if(this.products[i].CON010 > 0) {
            itens.push(item);
        }
    }

    if(itens.length > 0) {
        this.navCtrl.push('OrdersPage', {
            totalItens: this.totalItens,
            totalValor: this.totalValor,
            totalST: this.totalST,
            totalIPI: this.totalIPI,
            itensList: itens
        });
    } else {
        this.alertCtrl.create({
            title: 'Nenhum produto foi selecionado!',
            subTitle: 'Por favor verifique!' ,
            buttons: ['OK']
        }).present();
    }

}
}

select-client.ts:

import { Component } from '@angular/core';
import { IonicPage, NavController, NavParams, ToastController, AlertController } from 'ionic-angular';
import { ClientProvider } from '../../providers/client/client';

@IonicPage()
@Component({
selector: 'page-select-client',
templateUrl: 'select-client.html',
})
export class SelectClientPage {

clients:      any[]  = [];
searchClient: string = null;

constructor(
    public navCtrl: NavController,
    public navParams: NavParams,
    private clientProvider: ClientProvider,
    public alertCtrl: AlertController) {
}


ionViewDidEnter() {
    this.getAllClients();
}

ionViewDidLoad() {

}

getAllClients() {
    this.clientProvider.getAll(this.searchClient)
    .then((result: any[]) => {
        this.clients = result;
    });
}

filterClients(ev: any) {
    this.getAllClients();
}

selectClient(codigo, razsoc) {
    if(codigo != '' && razsoc != '') {
        this.navCtrl.push('OrdersPage', {
            codigo: codigo,
            razsoc: razsoc
        });
    } else {
        this.alertCtrl.create({
            title: 'Nenhum cliente foi selecionado!',
            subTitle: 'Por favor verifique!' ,
            buttons: ['OK']
        }).present();
    }
}
}