AHAH Example: Select control and generated checkboxes

Note that this is currently maintained in the Examples project so the code here may not be the latest.

In this example we use a select control to determine how many checkboxes are generated.

(Experience this one at http://d6.drupalexamples.info/examples/ahah_example/autocheckboxes.)

<?php
/<strong>
 * @
file
 
* A Self-configure a form based on a select control
 
* Add the number of checkboxes specified in the select
 
*/
function
ahah_demo_autocheckboxes(&$form_state) {

 
$default = !empty($form_state['values']['howmany']) ? $form_state['values']['howmany'] : 1;
 
$form['howmany'] = array(
   
'#title' => t('How many checkboxes do you want?'),
   
'#type' => 'select',
   
'#options' => array(1=>1, 2=>2, 3=>3, 4=>4),
   
'#default_value' => $default,
   
'#ahah' => array(
     
'path' => 'ahah_demo/autocheckboxes/callback',
     
'wrapper' => 'checkboxes',
     
'effect' => 'fade',
    ),

  );


 
$form['checkboxes'] = array(
   
'#title' => t("Generated Checkboxes"),
   
'#prefix' => '<div id="checkboxes">',
   
'#suffix' => '</div>',
   
'#type' => 'fieldset',
   
'#description' => t('This is where we get automatically generated checkboxes'),
  );

 
$num_checkboxes = !empty($form_state['values']['howmany']) ? $form_state['values']['howmany'] : 1;
  for (
$i=1; $i<=$num_checkboxes; $i++) {
   
$form['checkboxes']["checkbox$i"] = array(
     
'#type' => 'checkbox',
     
'#title' => "Checkbox $i",
    );
  }

 
$form['submit'] = array(
   
'#type' => 'submit',
   
'#value' => t('Click Me'),
  );


  return
$form;
}

/</
strong>
 *
Callback for autocheckboxes. Process the form with the number of checkboxes
 
* we want to provide
 
*/
function
ahah_demo_autocheckboxes_callback() {
 
$form_state = array('storage' => NULL, 'submitted' => FALSE);
 
$form_build_id = $_POST['form_build_id'];
 
$form = form_get_cache($form_build_id, $form_state);

 
$args = $form['#parameters'];
 
$form_id = array_shift($args);
 
$form_state['post'] = $form['#post'] = $_POST;
 
$form['#programmed'] = $form['#redirect'] = FALSE;

 
// HACK: Select values changing never get recognized
 
unset ($form['howmany']['#value']);

 
drupal_process_form($form_id, $form, $form_state);
 
$form = drupal_rebuild_form($form_id, $form_state, $args, $form_build_id);

 
$checkboxes = $form['checkboxes'];
 
$output = drupal_render($checkboxes);

 
// Final rendering callback.
 
print drupal_json(array('status' => TRUE, 'data' => $output));
  exit();
}
?>
Topics: 

2 comments

what do I do if I need check box 1 and 3 to be selected when its generated???

by rfay on Fri, 2010-06-11 06:21

Are you saying you want the checkboxes to retain their values?

Take a look at the current version of this in the Examples Project AHAH Example, where this is maintained. That was fixed recently.

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