FormTestClickedButtonForm.php

<?php

declare (strict_types=1);
namespace Drupal\form_test\Form;

use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;

/**
 * Form builder to test button click detection.
 *
 * @internal
 */
class FormTestClickedButtonForm extends FormBase {
  
  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    return 'form_test_clicked_button';
  }
  
  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state, $first = NULL, $second = NULL, $third = NULL) {
    // A single text field. In IE, when a form has only one non-button input
    // field and the ENTER key is pressed while that field has focus, the form
    // is submitted without any information identifying the button responsible
    // for the submission. In other browsers, the form is submitted as though
    // the first button were clicked.
    $form['text'] = [
      '#title' => 'Text',
      '#type' => 'textfield',
    ];
    // Get button configurations, filter out NULL values.
    $args = array_filter([
      $first,
      $second,
      $third,
    ]);
    // Define button types for each argument.
    $button_types = [
      's' => 'submit',
      'i' => 'image_button',
      'b' => 'button',
    ];
    // Loop through each path argument, adding buttons based on the information
    // in the argument. For example, if the path is
    // form-test/clicked-button/s/i/rb, then 3 buttons are added: a 'submit', an
    // 'image_button', and a 'button' with #access=FALSE. This enables form.test
    // to test a variety of combinations.
    foreach ($args as $index => $arg) {
      // Get the button type based on the index of the argument.
      $type = $button_types[$arg] ?? NULL;
      $name = 'button' . ($index + 1);
      if ($type) {
        // Define the button.
        $form[$name] = [
          '#type' => $type,
          '#name' => $name,
        ];
        // Image buttons need a #src; the others need a #value.
        if ($type == 'image_button') {
          $form[$name]['#src'] = 'core/misc/druplicon.png';
        }
        else {
          $form[$name]['#value'] = $name;
        }
        // 'r' for restricted, so we can test that button click detection code
        // correctly takes #access security into account.
        if (str_contains($arg, 'r')) {
          $form[$name]['#access'] = FALSE;
        }
      }
    }
    return $form;
  }
  
  /**
   * {@inheritdoc}
   */
  public function validateForm(array &$form, FormStateInterface $form_state) {
    if ($triggering_element = $form_state->getTriggeringElement()) {
      $this->messenger()
        ->addStatus($this->t('The clicked button is %name.', [
        '%name' => $triggering_element['#name'],
      ]));
    }
    else {
      $this->messenger()
        ->addStatus('There is no clicked button.');
    }
  }
  
  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    $this->messenger()
      ->addStatus('Submit handler for form_test_clicked_button executed.');
  }

}