function DynamicFormSections::buildForm
Same name in other branches
- 8.x-1.x ajax_example/src/Form/DynamicFormSections.php \Drupal\ajax_example\Form\DynamicFormSections::buildForm()
- 4.0.x modules/ajax_example/src/Form/DynamicFormSections.php \Drupal\ajax_example\Form\DynamicFormSections::buildForm()
Overrides FormInterface::buildForm
File
-
modules/
ajax_example/ src/ Form/ DynamicFormSections.php, line 34
Class
- DynamicFormSections
- Dynamically-enabled form with graceful no-JS degradation.
Namespace
Drupal\ajax_example\FormCode
public function buildForm(array $form, FormStateInterface $form_state, $nojs = NULL) {
// Add our CSS and tiny JS to hide things when they should be hidden.
$form['#attached']['library'][] = 'ajax_example/ajax_example.library';
// Explanatory text with helpful links.
$form['info'] = [
'#markup' => $this->t('<p>Like other examples in this module, this form has a path that
can be modified with /nojs to simulate its behavior without JavaScript.
</p><ul>
<li>@try_it_without_ajax</li>
<li>@try_it_with_ajax</li>
</ul>', [
'@try_it_without_ajax' => Link::createFromRoute($this->t('Try it without AJAX'), 'ajax_example.dynamic_form_sections', [
'nojs' => 'nojs',
])
->toString(),
'@try_it_with_ajax' => Link::createFromRoute($this->t('Try it with AJAX'), 'ajax_example.dynamic_form_sections')
->toString(),
]),
];
$form['question_type_select'] = [
// This is our select dropdown.
'#type' => 'select',
'#title' => $this->t('Question style'),
// We have a variety of form items you can use to get input from the user.
'#options' => [
'Choose question style' => 'Choose question style',
'Multiple Choice' => 'Multiple Choice',
'True/False' => 'True/False',
'Fill-in-the-blanks' => 'Fill-in-the-blanks',
],
// The #ajax section tells the AJAX system that whenever this dropdown
// emits an event, it should call the callback and put the resulting
// content into the wrapper we specify. The questions-fieldset-wrapper is
// defined below.
'#ajax' => [
'wrapper' => 'questions-fieldset-wrapper',
'callback' => '::promptCallback',
],
];
// The CSS for this module hides this next button if JS is enabled.
$form['question_type_submit'] = [
'#type' => 'submit',
'#value' => $this->t('Choose'),
'#attributes' => [
'class' => [
'ajax-example-inline',
],
],
// No need to validate when submitting this.
'#limit_validation_errors' => [],
'#validate' => [],
];
// This section allows us to demonstrate no-AJAX use without turning off
// javascript in the browser.
if ($nojs != 'nojs') {
// Allow JavaScript to hide the choose button if we're using AJAX.
$form['question_type_submit']['#attributes']['class'][] = 'ajax-example-hide';
}
else {
// Remove #ajax from the above, so it won't perform AJAX behaviors.
unset($form['question_type_select']['#ajax']);
}
// This fieldset just serves as a container for the part of the form
// that gets rebuilt. It has a nice line around it so you can see it.
$form['questions_fieldset'] = [
'#type' => 'details',
'#title' => $this->t('Stuff will appear here'),
'#open' => TRUE,
// We set the ID of this fieldset to questions-fieldset-wrapper so the
// AJAX command can replace it.
'#attributes' => [
'id' => 'questions-fieldset-wrapper',
'class' => [
'questions-wrapper',
],
],
];
// When the AJAX request comes in, or when the user hit 'Submit' if there is
// no JavaScript, the form state will tell us what the user has selected
// from the dropdown. We can look at the value of the dropdown to determine
// which secondary form to display.
$question_type = $form_state->getValue('question_type_select');
if (!empty($question_type) && $question_type !== 'Choose question style') {
$form['questions_fieldset']['question'] = [
'#markup' => $this->t('Who was the first president of the U.S.?'),
];
// Build up a secondary form, based on the type of question the user
// chose.
switch ($question_type) {
case 'Multiple Choice':
$form['questions_fieldset']['question'] = [
'#type' => 'radios',
'#title' => $this->t('Who was the first president of the United States'),
'#options' => [
'George Bush' => 'George Bush',
'Adam McGuire' => 'Adam McGuire',
'Abraham Lincoln' => 'Abraham Lincoln',
'George Washington' => 'George Washington',
],
];
break;
case 'True/False':
$form['questions_fieldset']['question'] = [
'#type' => 'radios',
'#title' => $this->t('Was George Washington the first president of the United States?'),
'#options' => [
'George Washington' => 'True',
0 => 'False',
],
'#description' => $this->t('Click "True" if you think George Washington was the first president of the United States.'),
];
break;
case 'Fill-in-the-blanks':
$form['questions_fieldset']['question'] = [
'#type' => 'textfield',
'#title' => $this->t('Who was the first president of the United States'),
'#description' => $this->t('Please type the correct answer to the question.'),
];
break;
}
$form['questions_fieldset']['submit'] = [
'#type' => 'submit',
'#value' => $this->t('Submit your answer'),
];
}
return $form;
}