Drupal 8: FormsDrupal 8: FormsWorking with forms in Drupal 8 modulesWorking with forms in Drupal 8 modules

Drupal Meetup StuttgartDrupal Meetup Stuttgart

05/07/2015

1. Creating a form1. Creating a form

<?php

/** * @file * Contains \Drupal\config\Form\ConfigExportForm. */

namespace Drupal\config\Form;

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

class ConfigExportForm extends FormBase {

public function getFormId() { return 'config_export_form'; }

public function buildForm(array $form, FormStateInterface $form_state) { $form['description'] = array( ... ); ... return $form; }

public function submitForm(array &$form, FormStateInterface $form_state) { ... }

}

Example: /modules/config/src/Form/ConfigExportForm.php

FormsFormsare classesextending base formsimplementing parent methods / propertiesusing the Drupal Form API

Examples for base formsExamples for base formsFormBase (generic)ConfigFormBase (settings forms)ConfirmFormBase (confirmation forms)XYZFormBase (roll your own)

<?php

/** * @file * Contains \Drupal\config\Form\ConfigExportForm. */

namespace Drupal\config\Form;

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

class ConfigExportForm extends FormBase {

public function getFormId() { return 'config_export_form'; }

public function buildForm(array $form, FormStateInterface $form_state) { $form['description'] = array( '#markup' => '<p>' . $this->t('Use the export button below to download your site configuration.') . '</p>', ); $form['submit'] = array( '#type' => 'submit', '#value' => $this->t('Export'), ); return $form; }

public function submitForm(array &$form, FormStateInterface $form_state) { $form_state->setRedirect('config.export_download'); }

}

Complete class: \Drupal\config\Form\ConfigExportForm

2. Rendering a form2. Rendering a form

ban.delete: path: '/admin/config/people/ban/delete/{ban_id}' defaults: _form: '\Drupal\ban\Form\BanDelete' _title: 'Delete IP address' requirements: _permission: 'ban IP addresses'

ban.routing.yml

<?php

namespace Drupal\ban\Form;

use Drupal\Core\Form\ConfirmFormBase;...

class BanDelete extends ConfirmFormBase {

...

}

Rendering a standalone form on a page

BanDelete.php

...

public function translatePage() { return array( 'filter' => $this->formBuilder()->getForm('Drupal\locale\Form\TranslateFilterForm'), 'form' => $this->formBuilder()->getForm('Drupal\locale\Form\TranslateEditForm'), ); }

...

\Drupal\locale\Controller\localeContoller

<?php

namespace Drupal\locale\Form;

use Drupal\Core\Form\FormStateInterface;

class TranslateFilterForm extends TranslateFormBase {

...

}

Embedding a form in other markup

\Drupal\locale\Form\TranslateFilterForm

3. Validating a form3. Validating a form

Validate =Validate =Checking form valuesCreate error messagesPrepare for form submission...

public function validateForm(array &$form, FormStateInterface $form_state) {

$this->file = file_save_upload('file', $form['file']['#upload_validators'], 'translations://', 0);

// Ensure we have the file uploaded. if (!$this->file) { $form_state->setErrorByName('file', $this->t('File to import not found.')) }

}

Example: \Drupal\locale\Form\ImportForm

public function validateForm(array &$form, FormStateInterface $form_state) {

$name = trim($form_state->getValue('name')); // Try to load by email. $users = $this->userStorage->loadByProperties(array('mail' => $name, 'status' => '1')); if (empty($users)) { // No success, try to load by name. $users = $this->userStorage->loadByProperties(array('name' => $name, 'status' => '1')); } $account = reset($users); if ($account && $account->id()) { $form_state->setValueForElement(array('#parents' => array('account')), $account); } else { $form_state->setErrorByName('name', $this->t('Sorry, %name is not recognized as a username or an email address.', array('%name' => $name))); }

}

Example: \Drupal\user\Form\UserPasswordForm

4. Submitting a form4. Submitting a form

Submit =Submit =Storing form valuesOutput messagesWrite log informationRedirect to new URL...

public function submitForm(array &$form, FormStateInterface $form_state) {

if ($form_state->getValue('confirm')) { $this->commentStorage->delete($this->comments); $count = count($form_state->getValue('comments')); $this->logger('content')->notice('Deleted @count comments.', array('@count' => $count)); drupal_set_message($this->formatPlural($count, 'Deleted 1 comment.', 'Deleted @count comments.')); }

$form_state->setRedirectUrl($this->getCancelUrl());

}

Example: \Drupal\comment\Form\ConfirmDeleteMultiple

public function submitForm(array &$form, FormStateInterface $form_state) {

$allowed_types = array_filter($form_state->getValue('book_allowed_types')); // We need to save the allowed types in an array ordered by machine_name so // that we can save them in the correct order if node type changes. // @see book_node_type_update(). sort($allowed_types); $this->config('book.settings') // Remove unchecked types. ->set('allowed_types', $allowed_types) ->set('child_type', $form_state->getValue('book_child_type')) ->save();

parent::submitForm($form, $form_state);

}

Example: \Drupal\book\Form\BookSettingsForm

5. Reusing existing forms5. Reusing existing forms

Reuse =Reuse =Create a new form based on an existing form

<?php

/** * @file * Contains \Drupal\block\Form\BlockDeleteForm. */

namespace Drupal\block\Form;

use Drupal\Core\Entity\EntityDeleteForm;use Drupal\Core\Url;

/** * Provides a deletion confirmation form for the block instance deletion form. */class BlockDeleteForm extends EntityDeleteForm {

/** * {@inheritdoc} */ public function getCancelUrl() { return new Url('block.admin_display'); }

}

Example: \Drupal\block\Form\BlockDeleteForm

6. Modifying forms6. Modifying forms

Some old friends:Some old friends:hook_form_alter()hook_form_FORM_ID_alter()hook_form_BASE_FORM_ID_alter()

...use Drupal\Core\Form\FormStateInterface;...

function mymodule_form_node_form_alter(&$form, FormStateInterface $form_state, $form_id) {

// Add a checkbox to the node form about agreeing to terms of use. $form['terms_of_use'] = array( '#type' => 'checkbox', '#title' => t("I agree with the website's terms and conditions."), '#required' => TRUE, );

}

Example: mymodule.module

Thank You!Thank You!

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