After submitting the form, providing a file, I get the error: "Field is required" - drupal

Question

I have this form: https://greektoenglish.com/translation
After I complete the form, provide it with a file, and finally submit it, I get this error: "field is required". That the file field is required. But I already completed the field.
If I remove "'#required' => TRUE," from the code where the file upload field is declared, fill the form out, and submit it, then the form is submitted correctly.
How can I solve this?
This is my code:
<?php
namespace Drupal\submit_translation\Form;
use Drupal\Component\Utility\EmailValidatorInterface;
use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Language\LanguageManagerInterface;
use Drupal\Core\Mail\MailManagerInterface;
use Drupal\mimemail\Utility\MimeMailFormatHelper;
use Symfony\Component\DependencyInjection\ContainerInterface;
/**
* The example email contact form.
*/
class SubmitTranslation extends FormBase {
/**
* The email.validator service.
*
* #var \Drupal\Component\Utility\EmailValidatorInterface
*/
protected $emailValidator;
/**
* The language manager service.
*
* #var \Drupal\Core\Language\LanguageManagerInterface
*/
protected $languageManager;
/**
* The mail manager service.
*
* #var \Drupal\Core\Mail\MailManagerInterface
*/
protected $mailManager;
/**
* Constructs a new ExampleForm.
*
* #param \Drupal\Component\Utility\EmailValidatorInterface $email_validator
* The email validator service.
* #param \Drupal\Core\Language\LanguageManagerInterface $language_manager
* The language manager service.
* #param \Drupal\Core\Mail\MailManagerInterface $mail_manager
* The mail manager service.
*/
public function __construct(EmailValidatorInterface $email_validator, LanguageManagerInterface $language_manager, MailManagerInterface $mail_manager) {
$this->emailValidator = $email_validator;
$this->languageManager = $language_manager;
$this->mailManager = $mail_manager;
}
/**
* {#inheritdoc}
*/
public static function create(ContainerInterface $container) {
return new static(
$container->get('email.validator'),
$container->get('language_manager'),
$container->get('plugin.manager.mail')
);
}
/**
* {#inheritdoc}
*/
public function getFormId() {
return 'submit_translation_form';
}
/**
* {#inheritdoc}
*/
public function buildForm(array $form, FormStateInterface $form_state, $dir = NULL, $img = NULL) {
$form['intro'] = [
'#markup' => $this->t('Use this form to send us the document that we\'ll translate!'),
];
$form['from'] = [
'#type' => 'textfield',
'#title' => $this->t('Name'),
'#description' => $this->t("Your full name."),
'#required' => TRUE,
];
$form['from_mail'] = [
'#type' => 'textfield',
'#title' => $this->t('Email address'),
'#description' => $this->t("Your email address."),
'#required' => TRUE,
];
$form['params'] = [
'#tree' => TRUE,
'subject' => [
'#type' => 'textfield',
'#title' => $this->t('Title'),
'#description' => $this->t("The title of the document."),
'#required' => TRUE,
],
'count' => [
'#type' => 'textfield',
'#title' => $this->t('Word Count'),
'#description' => $this->t("The word count of the document."),
'#required' => TRUE,
],
'body' => [
'#type' => 'textarea',
'#title' => $this->t('Comments'),
'#description' => $this->t("Tell us if you have any special requirements."),
'#required' => TRUE,
],
// This form element forces plaintext-only email when there is no HTML
// content (that is, when the 'body' form element is empty).
'plain' => [
'#type' => 'hidden',
'#states' => [
'value' => [
':input[name="body"]' => ['value' => ''],
],
],
],
'attachments' => [
'#name' => 'files[attachment]',
'#type' => 'file',
'#title' => $this->t('Choose a file to send for translation.'),
'#required' => TRUE,
],
];
$form['submit'] = [
'#type' => 'submit',
'#value' => $this->t('Send message'),
];
return $form;
}
/**
* {#inheritdoc}
*/
public function validateForm(array &$form, FormStateInterface $form_state) {
// Extract the address part of the entered email before trying to validate.
// The email.validator service does not work on RFC2822 formatted addresses
// so we need to extract the RFC822 part out first. This is not as good as
// actually validating the full RFC2822 address, but it is better than
// either just validating RFC822 or not validating at all.
$pattern = '/<(.*?)>/';
$address = $form_state->getValue('from_mail');
preg_match_all($pattern, $address, $matches);
$address = isset($matches[1][0]) ? $matches[1][0] : $address;
if (!$this->emailValidator->isValid($address)) {
$form_state->setErrorByName('from_mail', $this->t('That email address is not valid.'));
}
$file = file_save_upload('attachment', [ 'file_validate_extensions' => array('doc docx pdf')], 'temporary://', 0);
if ($file) {
$form_state->setValue(['params', 'attachments'], [['filepath' => $file->getFileUri()]]);
}
}
/**
* {#inheritdoc}
*/
public function submitForm(array &$form, FormStateInterface $form_state) {
// First, assemble arguments for MailManager::mail().
$module = 'submit_translation';
$key = "solon_key";
$to = "info#gexl.eu";
$langcode = $this->languageManager->getDefaultLanguage()->getId();
$params = $form_state->getValue('params');
$reply = "";
$send = TRUE;
$params['body'] .= " Count: " . $params['count'];
// Second, add values to $params and/or modify submitted values.
// Set From header.
if (!empty($form_state->getValue('from_mail'))) {
$params['headers']['From'] = MimeMailFormatHelper::mimeMailAddress([
'name' => $form_state->getValue('from'),
'mail' => $form_state->getValue('from_mail')
]);
}
elseif (!empty($form_state->getValue('from'))) {
$params['headers']['From'] = $from = $form_state->getValue('from');
}
else {
// Empty 'from' will result in the default site email being used.
}
// Handle empty attachments - we require this to be an array.
if (empty($params['attachments'])) {
$params['attachments'] = [];
}
// Remove empty values from $param['headers'] - this will force the
// the formatting mailsystem and the sending mailsystem to use the
// default values for these elements.
foreach ($params['headers'] as $header => $value) {
if (empty($value)) {
unset($params['headers'][$header]);
}
}
// Finally, call MailManager::mail() to send the mail.
$result = $this->mailManager->mail($module, $key, $to, $langcode, $params, $reply, $send);
if ($result['result'] == TRUE) {
$this->messenger()->addMessage($this->t('Your message has been sent.'));
}
else {
// This condition is also logged to the 'mail' logger channel by the
// default PhpMail mailsystem.
$this->messenger()->addError($this->t('There was a problem sending your message and it was not sent.'));
}
}
}

Answer 1

This happens because the form element '#type' => 'file' has no #value to validate. #required fields must have a #value set otherwise validation fails.
This is (now considered) a very old issue that has been fixed in Drupal 9.5.x, but this was assumed in the good old days of Drupal 7, as mentioned in the Form API reference :
#required: Indicates whether or not the element is required. This
automatically validates for empty fields, and flags inputs as
required. File fields are NOT allowed to be required.
So I guess the best solution is to upgrade to 9.5.x or above, if feasible, but as sometimes upgrading makes things complicated, you might prefer to review and apply the patch manually to your current code base.
[EDIT]: If still having issues after upgrade to >= 9.5.2,
Looking at the patch, a default valueCallback is now used to provide a #value to file form elements, but.. well there is another issue :
public static function valueCallback(&$element, $input, FormStateInterface $form_state) {
if ($input === FALSE) {
return NULL;
}
$parents = $element['#parents'];
$element_name = array_shift($parents); # <- problem here :/
$uploaded_files = \Drupal::request()->files->get('files', []);
$uploaded_file = $uploaded_files[$element_name] ?? NULL;
if ($uploaded_file) {
// Cast this to an array so that the structure is consistent regardless of
// whether #value is set or not.
return (array) $uploaded_file;
}
return NULL;
}
See how it doesn't care about whether or not the element has a #name explicitly defined ? and whether or not #parents is a tree ? Now because of those wrong assumptions on the element's name and its parents, you are somehow forced to either :
Leave the #name property unset and refer to the file later on validation/submit as 'params' (the parents root) instead of 'attachment'. Or,
Stick with #tree => FALSE. Or,
Provide your own #value_callback (deprecated ...?)