Programmatic modification

18. Programmatic View Modification

When to Use

When config-based approach isn't sufficient: runtime view modification, dynamic filter injection, custom display logic.

Philosophy: Config-first is preferred. Only use programmatic modification when config can't solve the problem.

Loading Views

Load View Config Entity

$view = \Drupal\views\Entity\View::load('my_view');
// Returns ViewEntityInterface (config entity)
// Use for: reading config, checking existence, deleting

Load Executable View

$view = \Drupal::service('views.executable')->get('my_view');
// Returns ViewExecutable
// Use for: executing, altering, rendering

Reference: core/modules/views/src/Entity/View.php lines 123-130

Executing Views Programmatically

Basic Execution

$view = \Drupal\views\Views::getView('my_view');
$view->setDisplay('page_1');
$view->execute();
$results = $view->result;

Rendering View

$view = \Drupal\views\Views::getView('my_view');
$view->setDisplay('block_1');
$view->setArguments([123]);  // Contextual filter values
$render_array = $view->render();

With Filters

$view = \Drupal\views\Views::getView('my_view');
$view->setDisplay('default');
$view->setExposedInput(['type' => 'article']);
$view->execute();

Altering Views with Hooks

hook_views_pre_view()

Runs before view execution.

/**
 * Implements hook_views_pre_view().
 */
function mymodule_views_pre_view(\Drupal\views\ViewExecutable $view, $display_id, array &$args) {
  if ($view->id() == 'my_view' && $display_id == 'page_1') {
    // Modify view before execution
    $view->setItemsPerPage(20);
  }
}

hook_views_pre_render()

Runs after query execution, before rendering.

/**
 * Implements hook_views_pre_render().
 */
function mymodule_views_pre_render(\Drupal\views\ViewExecutable $view) {
  if ($view->id() == 'my_view') {
    // Modify results before rendering
    foreach ($view->result as $row) {
      // Manipulate row data
    }
  }
}

hook_views_post_render()

Runs after rendering.

/**
 * Implements hook_views_post_render().
 */
function mymodule_views_post_render(\Drupal\views\ViewExecutable $view, &$output, \Drupal\views\Plugin\views\cache\CachePluginBase $cache) {
  if ($view->id() == 'my_view') {
    // Modify render array
    $output['#suffix'] = '<div class="custom-footer">Footer text</div>';
  }
}

Creating Views Programmatically

Create View Entity

$view = \Drupal\views\Entity\View::create([
  'id' => 'my_custom_view',
  'label' => 'My Custom View',
  'module' => 'mymodule',
  'base_table' => 'node_field_data',
  'base_field' => 'nid',
  'display' => [
    'default' => [
      'display_plugin' => 'default',
      'id' => 'default',
      'display_title' => 'Default',
      'position' => 0,
      'display_options' => [],
    ],
  ],
]);
$view->save();

Reference: core/modules/views/src/Entity/View.php lines 374-390

Pattern: Dynamic Contextual Filter

function mymodule_views_pre_view(\Drupal\views\ViewExecutable $view, $display_id, array &$args) {
  if ($view->id() == 'related_content') {
    // Inject current node ID as argument
    $node = \Drupal::routeMatch()->getParameter('node');
    if ($node) {
      $args[0] = $node->id();
    }
  }
}

Common Mistakes

Creating views programmatically instead of using config → Config is exportable, versionable; code is not
Not checking view existence before loading → Views::getView() returns NULL if view doesn't exist; always check
Modifying view in wrong hook → hook_views_pre_view() for query changes, hook_views_pre_render() for result changes, hook_views_post_render() for output changes
Forgetting to set display → setDisplay() required before execute() or render()
Not calling execute() before accessing results → $view->result is empty until execute() runs