Update multiple fields using #ajax in Drupal 7 form

     We know how to replace a field using #ajax in a form. Can we update multiple fields using #ajax in a form? Yes, we can update multiple fields using #ajax in the Drupal 7. We can achieve it using ajax_command_replace() in Drupal 7. For more details about ajax commands on Drupal 7, please visit https://api.drupal.org/api/drupal/7.x/search/ajax_command.

Update fields using #ajax in a Drupal form:

    Consider the following example. In this example, I've created a form with fields First, Second & Third name. I tried to update the Second & Third name fields when focus out on the First name field.

/**

 * Implments hook_form()

 */

function phponwebsites_ajax_form($form, &$form_state) {

  $form['firstname'] = array(

    '#title' => t('First name'),

    '#type' => 'textfield',

    '#ajax' => array(

      'callback' => '_generate_textfield',

      'wrapper' => 'copied-text-field',

    )

  );

  $form['secondname'] = array(

    '#title' => t('Second name'),

    '#type' => 'textfield',

    '#prefix' => '<div id="copied-secondname">',

    '#suffix' => '</div>',

  );

  $form['thirdname'] = array(

    '#title' => t('Third name'),

    '#type' => 'textfield',

    '#prefix' => '<div id="copied-thirdname">',

    '#suffix' => '</div>',

  );

  $form['submit'] = array(

    '#type' => 'submit',

    '#value' => 'Submit'

  );

  return $form;

}

function _generate_textfield($form, &$form_state) {

  if (!empty($form_state['values']['firstname'])) {

    $form['secondname']['#value'] =  $form_state['values']['firstname'];

    $form['thirdname']['#value'] =  $form_state['values']['firstname'];

  }

  $commands = array();

  $commands[] = ajax_command_replace('#copied-secondname', drupal_render($form['secondname']));

  $commands[] = ajax_command_replace('#copied-thirdname', drupal_render($form['thirdname']));

  return array('#type' => 'ajax', '#commands' => $commands);

}

When you tried to execute the above codes, it'll populate the same name on the other 2 fields. It looks likes the below image:

Now I hope you know how to populate multiple fields using #ajax in Drupal 7 forms.

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