Grand Totals Not Updating Upon Delete

JavaScript
1

I am using a getter to update the grand totals. When I click on the deleteItem button, the grand total isn’t updated and the table cell displays the same grand total as before even though items have been removed. How can I fix this?

In the HTML:

<form name="yourForm" [formGroup]="yourForm">
<table>
<tr *ngFor="let item of items; let i = index">
<td><td></td>
<button type="button" (click)="deleteItem(i)" class="deletebtn">X</button></td>
<td>{{item.quantity}} </td>
<td>{{item.product_price }} </td>
<td>{{item.quantity * item.product_price }}</td>
</tr>
<tr><td></td><td></td><td><b>Grand Total</b> </td><td><b>{{grandTotal }}</b></td></tr>
</table>

In the component:

  totals = [];
  get grandTotal() {
    let i;
    let sub_total = 0;
    let grand_total = 0;
    if (this.isSubmitted == true) {
      if (
        typeof this.product_price !== "undefined" &&
        typeof this.quantity !== "undefined"
      ) {
        sub_total = this.product_price * this.quantity;
        this.totals.push(sub_total);
      }
    }

    for (i = 0; i < this.totals.length; i++) {
      grand_total += this.totals[i];
    }
    this.isSubmitted = false;
    return grand_total;
  }

  deleteItem(i) {
    this.totals = [];
 this.isSubmitted = true;
    this.grandTotal;
    this.items.splice(i, 1);
    this.setStorageItems(this.items);
   
  }
2

Shouldn’t this.grandTotal; be
this.grandTotal = this.getGrandTotal();
?

3

Thanks for the suggestion, jenovs. The function is grandTotal() and not getGrandTotal() and when I add it to my code, I get the errors: Cannot assign to ‘grandTotal’ because it is a read-only property and this expression is not callable Type ‘Number’ has no call signatures.

4

Ah, ok. The formatting threw me off :slightly_smiling_face:

Try to replace

this.items.splice(i,1);

with

this.items = this.items.filter((_, j) => j !== i);
5

I added that and now it updates the grand total with the price that has just been deleted. It doesn’t work.

6

It does the same thing that splice does.

7

No, it doesn’t. Splice changes the array in place, filter creates new array.

Maybe you could create a working example in https://codesandbox.io/ ?