how to delete multiple items with checkbox in ionic 3 - checkbox

Question

I would like to know how to delete multiple items from the list in Ionic 3, using CheckBox, here is my code, in the delete () function I do not know how to only exclude the products that are checked with the checkbox. I thought that this would work but did not delete anything . If anyone can help me, thank you.
produto.html
<ion-item-sliding *ngFor="let produto of produtos">
<ion-item>
<input [(ngModel)]="modelo[produto.id]" value="{{produto.id}}" name="modelo" type="checkbox" ng-checked="produto.checked">{{produto.id}}
<h1> {{ produto.barra }}</h1>
<h3> {{ produto.deposito_nome }}</h3>
<h3> {{ produto.quantidade }}</h3>
<!--<h2 class="price">{{ produto.preco | currency:'BRL':true }}</h2> -->
</ion-item>
</ion-item-sliding>
</ion-list>
<button ion-button (click)="excluir()">Excluir Todos</button>
import { Component } from '#angular/core';
import { DatabaseProvider } from '../../providers/database/database';
import { SQLiteObject } from '#ionic-native/sqlite';
import { NavController, NavParams, ToastController } from 'ionic-angular';
import { InventarioProvider, Product } from '../../providers/inventario/inventario';
import { RestProvider } from '../../providers/rest/rest';
import { HomePage } from '../home/home';
#Component({
selector: 'page-inventario',
templateUrl: 'inventario.html',
})
export class InventarioPage {
produtos: any[] = [];
modelo: any[] = [];
this.model = new Product();
if (this.navParams.data.id) {
this.inventarioProvider.get(this.navParams.data.id)
.then((result: any) => {
this.model = result;
})
}
}
ionViewDidEnter() {
this.getAllProdutos();
}
getAllProdutos() {
this.inventarioProvider.getAll()
.then((result: any[]) => {
this.produtos = result;
});
}
excluir() {
this.produtos.forEach(function (produto) {
if (produto.checked) {
this.modelo[produto.id] = produto.checked;
return this.dbProvider.getDB()
.then((db: SQLiteObject) => {
let sql = 'delete from inventario where id = ?';
let data = [produto.id];
return db.executeSql(sql, data)
})
}
})
}
}

Answer 1

Hey I never worked with SQlite but assuming the other parts of your code work including the db handling, you need to do something like the below in your delete method:
excluir() {
// create comma separated list of products to be deleted from db:
const toBeDeleted = this.produtos.filter(produto => produto.checked === true);
// now execute db script to delete multiple products:
return this.dbProvider.getDB().then((db: SQLiteObject) => {
// here i might be wrong but you should be able to delete all items with ids in one operation, don't use loop as it may get expensive:
db.delete("inventario", "id IN (?)", toBeDeleted.join())
db.close()
}).then(() => {
// now do the modelo step (not sure what is this though in your case):
toBeDeleted.forEach(produto => {
this.modelo[produto.id] = produto.checked;
})
// finally update product array by filtering out deleted items:
this.produtos = this.produtos.filter(produto => produto.checked === false);
})
}
Please note I am not entirely sure how you use delete multiple items using SQlite, but I hope you know that part. I think you might need to do this way:
db.delete("inventario", "id IN (" + toBeDeleted.join() + ")", null)