Alter views results in a hook

Question

When I use contextual filters in a view, I can select an option to display a summary when the argument is not present. If I do it, it shows a list of node IDs instead of titles. For example, I get the following output, where the first number is the node ID, and the second number is the count of nodes.

• 1256 (12)
• 4323 (723)
• 5643 (34)

I want is to rewrite the output and replace the node ID with its title. ViewExecutable has a $args property I can check to know when the argument is not present.

How could I achieve this in a hook? In Drupal 7 I could use hook_views_post_execute(). I modified $view->result and changed it on my own.

I tried to do the same with Drupal 8 and the same hook, but hook_views_pre_render() gets a ViewExecutable object, and I don't know how to change it. I used the following code.

function MYMODULE_views_pre_render(ViewExecutable $view) {
  if ($view->id() == 'myidoftheview') {
    $results = $view->result;
    foreach ($results as $result) {
      \Drupal::logger('myview')->notice('<pre>'.print_r($result,TRUE).'</pre>');
      // What code should I write here?
    }    
  }
}

Answer 1

I was able to alter results just setting the view result property within hook_views_pre_render. My code looks something like:

$results = $view->result;
$filteredResults = [];

foreach ($results as $result) {
  if ($result->_entity->field_somefield->value === 'somevalue') {
    $filteredResults[] = $result;
  }
}

$view->result = $filteredResults;
$view->total_rows = count($filteredResults);

Answer 2

It depends on what your result stores. It can be like entity with relation or just field:

1) $result->_entity->set('field_Name', 'xxxxxxxxxxx');

2) $value->node__field_Name = 'xxxxxxxxxxx';

Answer 3

View hooks like hook_views_pre_render() should be placed in an execution.inc file within the module directory: mymodule.views_execusion.inc

The execution order of View hooks is as follows:

1. hook_views_pre_view
2. hook_views_pre_build
3. hook_views_post_build
4. hook_views_pre_execute
5. hook_views_post_execute
6. hook_views_pre_render
7. hook_views_post_render

Read what these hooks do here

The following is a good example for Drupal 8.x|9.x. Your goal is to create a new result set of entities and set it to $view->result. It is important to set the index property so the results will render properly.

Slightly altered from @rosemarystanley

/**
 * Implements hook_views_pre_render().
 */
function HOOK_views_pre_render(ViewExecutable $view) {

  $results = $view->result;
  $filteredResults = [];

  foreach ($results as $result) {
    if ($result->_entity->field_name->value === 'fieldValue') {
      $filteredResults[] = $result;
    }
  }

  // Important to set index values for view results rendering
  foreach ($filteredResults as $key => $row) {
    $row->index = $key;
  }

  $view->result = $filteredResults;
  $view->total_rows = count($filteredResults);
}