Perform math calculation in views

Question

On Drupal 8 site, I have a exact copy of the below excel example table made with views but without the yellow cell yet.

The view is displaying one content type: Client where all the below fields are available:

• Date
• Client Name
• Client ID
• Amount ($)

Now, as you can see, the yellow cell is displaying the total SUM of all amount ($) rows. which basically is: 15+29+97+115+45+67+23+11+5+91+44 = 542$

How can i achieve this exact calculation in my view ?

I have tried to enable the Use aggregation option under the advanced section on my view, but it seems it doesn't do what i am asking for!

any help please ?

Note: I believe the use Use aggregation option doesn't add a row at the bottom of the table calculating the sum of all above rows and therefore this question Making a colums total (SUM) with Views is not a possible duplicate of this one.

UPDATE #1

After following the answer of @Stef Van Looveren, I am encountering a new error:

InvalidArgumentException: Field field_money_amount is unknown. in Drupal\Core\Entity\ContentEntityBase->getTranslatedField() (line 587 of /home/####/public_html/#####/web/core/lib/Drupal/Core/Entity/ContentEntityBase.php)

Knowing that: field_money_amount is the id of the field taken from the content type being used inside the view.

Complete code in the .module file:

<?php

use Drupal\views\ViewExecutable;

function my_module_views_pre_render(ViewExecutable $view){
  if ($view->id() == "view_id" && $view->current_display == 'display_id') {
    $total = 0;
    foreach ($view->result as $value) {
      $number = $value->_entity->get('field_money_amount')->value;
      $total += $number;
    }
    $view->attachment_after = [
      '#markup' => '<table class="table cols-0"><tr><td>Total:</td><td>'.$total.'</td></tr></table>',
      '#allowed_tags' => ['table','tr','td']
    ];
  }

}

Answer 1

Interesting question and a typical use case. In a custom module, do the following:

use Drupal\views\ViewExecutable;

function helper_views_pre_render(ViewExecutable $view){
  if ($view->id() == "numbers" && $view->current_display == 'page_1') {
    $total = 0;
    foreach ($view->result as $value) {
      $number = $value->_entity->get('field_number')->value;
      $total += $number;
    }
    $view->attachment_after = [
      '#markup' => '<table class="table cols-0"><tr><td>Total:</td><td>'.$total.'</td></tr></table>',
      '#allowed_tags' => ['table','tr','td']
    ];
  }
}

Change the names according to your view name & field names. I'm sure you get the point: you add a table below with the total result.

I did a test and it gave me the following result:

Answer 2

After further search, I have found Views Aggregator module to do exactly what I need to do.

I am willing to accept @Stef Van Looveren answer especially where i prefer not to have to add a new module to my site but for some reason isn't working for me, unless somebody can help fix the above provided code.