An illegal choice has been detected. Please contact the site administrator.in dynamic select list dependent dropdown

Question

using hook_form_alter and custom form elements below

$form['get-quotes-shipping']['country'] = array(
      '#type' => 'select',
      '#options' => array('_none' => '- None -') + country_get_list(),
      '#multiple' => FALSE,
      '#weight' => 3,
      '#title'=>t('Country'),
      '#default_value' => (isset($_SESSION['selected_country'])) ? $_SESSION['selected_country'] : '_none',
      '#ajax' => array(
          'event' => 'change',
            'wrapper' => 'squadron-wrapper',
            'callback' => '_get_state_field',
            'method' => 'replace',
       ),
    );






    $form['get-quotes-shipping2']['actions']['get_quotes'] = array(
      '#type' =>'submit',
      '#value' => 'Get Quotes',
       '#submit' => array('custom_changes_get_quotes_submit'),
      '#validate' => array('custom_changes_get_quotes_validate'),
      '#weight' => 1,
    );


  $squadron_options = array();
   if (isset($_SESSION['selected_country'])) {
       module_load_include('inc', 'location');
       $states = location_get_provinces($_SESSION['selected_country']);
       $squadron_options =  $states;
   }
   $form['get-quotes-shipping0']['states']['#type'] = 'select'; 
     $form['get-quotes-shipping0']['states']['#title'] = t('State/Province');


   $form['get-quotes-shipping0']['states']['#prefix'] = '<div id="squadron-wrapper">';
   $form['get-quotes-shipping0']['states']['#suffix'] = '</div>';
    $form['get-quotes-shipping0']['states']['#options'] = array('_none' => '- None -') + $squadron_options;
    if (isset($squadron_options[0])) {
      $form['get-quotes-shipping0']['states']['#default_value'] =  $squadron_options[0];
    }

---

Callback function as given below.

function _get_state_field(&$form,&$form_state) {
  module_load_include('inc', 'location');
  if ($form_state['values']['country'] == '_none') {
    unset($form['get-quotes-shipping0']['states']['#options']);
    $form['get-quotes-shipping0']['states']['#default_value'] = '_none';
     return $form['get-quotes-shipping0']['states'];

  }
  else {
      $states = location_get_provinces($form_state['values']['country']);
 $form['get-quotes-shipping0']['states']['#options'] = $states;
     return $form['get-quotes-shipping0']['states'];

  }

}

When I select Country and then state at first it gives proper values but when I select country again it gives An illegal choice has been detected

What is the issue with the above code? can anyone point out?

Answer 1

i recently made a 3 level dependent dropdown and had the same issue with some of the problems i found on the way. First you need to re-organize your code a little bit more. have in mind that the callback function should normaly look something like this:

//callback
    function _get_state_field(&$form,&$form_state) {

     return $form['get-quotes-shipping0']['states'];
}

Any code inside the callback has the potential to intervene with the proccess, with some exceptions.

Without taking a longer look to your code i think it should look somethink like this:

<?php

 module_load_include('inc', 'location');
  if ($form_state['values']['country'] == '_none') {
    unset($form['get-quotes-shipping0']['states']['#options']);
    $form['get-quotes-shipping0']['states']['#default_value'] = '_none';
     return $form['get-quotes-shipping0']['states'];

  }
  else {
      $states = location_get_provinces($form_state['values']['country']);
 $form['get-quotes-shipping0']['states']['#options'] = $states;
  }

$form['get-quotes-shipping']['country'] = array(
      '#type' => 'select',
      '#options' => array('_none' => '- None -') + country_get_list(),
      '#multiple' => FALSE,
      '#weight' => 3,
      '#title'=>t('Country'),
      '#default_value' => (isset($_SESSION['selected_country'])) ? $_SESSION['selected_country'] : '_none',
      '#ajax' => array(
          'event' => 'change',
            'wrapper' => 'squadron-wrapper',
            'callback' => '_get_state_field',
            'method' => 'replace',
       ),
    );


    $form['get-quotes-shipping2']['actions']['get_quotes'] = array(
      '#type' =>'submit',
      '#value' => 'Get Quotes',
       '#submit' => array('custom_changes_get_quotes_submit'),
      '#validate' => array('custom_changes_get_quotes_validate'),
      '#weight' => 1,
    );



   $form['get-quotes-shipping0']['states']['#type'] = 'select'; 
     $form['get-quotes-shipping0']['states']['#title'] = t('State/Province');


   $form['get-quotes-shipping0']['states']['#prefix'] = '<div id="squadron-wrapper">';
   $form['get-quotes-shipping0']['states']['#suffix'] = '</div>';
    $form['get-quotes-shipping0']['states']['#options'] = array('_none' => '- None -') + $squadron_options;
    if (isset($squadron_options[0])) {
      $form['get-quotes-shipping0']['states']['#default_value'] =  $squadron_options[0];
    }


    //callback
    function _get_state_field(&$form,&$form_state) {

     return $form['get-quotes-shipping0']['states'];
}
?>

This is the code i wrote, try to follow the same structure it's working for me perfectly.

Tell us how it went, have a good coding!