We have a form with three fields - where depending on the value of the first select field, we will show the other two form elements - one select field (the options depends on the value of the first select field) and one file upload field.

The issue is that when I upload a file the second select list value is resetting. Because managed_file form element is again calling an ajax function which overrides the value of my first ajax call

Code is below:

public function buildForm(array $form, FormStateInterface $form_state) {
    $texts = array();
    $text_values = db_query("SELECT text_id, title FROM `heritage_text_structure`")->fetchAll();
    foreach($text_values AS $key => $value){
        $texts[$value->text_id] = $value->title;
    }
    $form['text'] = array(
        '#type' => 'select',
        '#title' => $this->t('Select the heritage text'),
        '#required' => TRUE,
        '#options' => $texts,
        '#default_value' => isset($form['text']['#default_value'])?$form['text']['#default_value']:null,
        '#ajax' => array(
            'event' => 'change',
            'wrapper' => 'text-info',
            'callback' => '::_ajax_text_callback',
        ),
    );
    if(!empty($form_state->getTriggeringElement())) {
        $description = '';
        $text_id = $form_state->getTriggeringElement()['#value'];
        $labels = db_query("SELECT level_labels FROM `heritage_text_structure` WHERE text_id = :text_id", array(':text_id' => $text_id))->fetchField();
        $labels_array = explode(',', $labels);
        $label_count = count($labels_array);
        for($i=0; $i<count($labels_array); $i++){
            if($i < $label_count-1)
                $description = $description.$labels_array[$i].', ';
            else $description = $description.$labels_array[$i];
        }
        $description = $description.', Content, Language';
        $csvCount = $label_count + 2;
    }
    $form['text_info'] = array(
        '#type' => 'container',
        '#prefix' => '<div id="text-info">',
        '#suffix' => '</div>'
    );
    if(isset($text_id) && $text_id > 0){
        $validators = array(
            'file_validate_extensions' => array('csv '),
        );
        $form['text_info']['fieldset'] = array(
            '#type' => 'fieldset',
            '#title' => $this->t('Select the Target Source'),
            '#description' => $this->t('Choose the source into which you are importing content'), 
        );
        $sources = array();
        $source_values = db_query("SELECT id, title FROM `heritage_source_nodes` WHERE text_id = :text_id", array('text_id' => $text_id))->fetchAll();
        foreach($source_values AS $key => $value){
            $sources[$value->id] = $value->title;
        }
        $form['text_info']['fieldset']['sources'] = array(
            '#type' => 'select',
            '#title' => $this->t('Select the Source to which content is imported'),
            '#required' => TRUE,
            '#options' => $sources,
            '#default_value' => isset($form['text_info']['fieldset']['sources']['widget']['#default_value'])?$form['text_info']['fieldset']['sources']['widget']['#default_value']:null,
        );
        $form['text_info']['fieldset']['file'] = array(
            '#type' => 'managed_file',
            '#title' => t('Upload the Content in CSV format'),
            '#size' => 20,
            '#description' => t('CSV file (eg: '.$description.'). Please maintain the order of the fields.'),
            '#upload_location' => 'public://file_uploads/',
            '#upload_validators' => $validators,
        );
        $form['text_info']['fieldset']['csv_count'] = array(
            '#type' => 'hidden',
            '#value' => $csvCount,
        );
    }
    $form['actions']['submit'] = array(
        '#type' => 'submit',
        '#value' => $this->t('Import Content'),
    );
    return $form;
}
/**
* {@inheritdoc} Map content to the corresponding fields.
*/
public function submitForm(array &$form, FormStateInterface $form_state) {
    $text = $form_state->getValue('text');
    print("<pre>");print_r($form_state->getValue());exit;
}

/**
* Ajax callback function
*/
public function _ajax_text_callback(array $form, FormStateInterface $form_state) {
    return $form['text_info'];
}

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Browse other questions tagged or ask your own question.