Set the value of a hidden form component

Question

I have a Webform in drupal 7. I want to add a hidden field porgramatically to it, and I would like to set the value of this field per form. I want to achieve all these in a custom submit function, as I want to use the sid (serial ID) of the Submission, to generate a unique ID for each Submission. At the moment everything is working, except to set the value. I googled it a lot, tried out hundreds of codes but non of them worked in my case.

Here is my code:

<?php
$form['#submit'][] = 'webform_custom_submit';

function webform_custom_submit($form, &$form_state) {
  if ( !array_key_exists('my_uniq_id', $form['#node']->webform['cids'] ) ){
    $components = array(
      0 => array(
        'name' => 'My Unique ID',
        'form_key' => 'my_unique_id',
        'type' => 'hidden',
        'weight' => 1,
        'pid' => 0
      )
    );
    webform_ensure_record($form['#node']);
    foreach ($components as $component) {
      $component['nid'] = $form['#node']->nid;
      $form['#node']->webform['components'][] = $component;
      webform_component_insert($component);
    }
  }
  $my_uniqe_key = generate_some_unique_key_function();
  //Here I wan't to set the value of the component 'my unique ID', but nothing worked yet
  $form_state['my_unique_id']['#value'] = $my_uniqe_key;
}

Thanks for the help, I'm sure I could find the answer somewhere, but I tried it 3hours long...

Here is the $form and $form_state written out with dpm from my webform_custom_submit function.

And here are some codes, I tried already:

<?php
$form['values']['my_unique_id'] = $my_uniqe_key;
$form['values']['my_unique_id']['#value'] = $my_uniqe_key;
$form['values']['my_unique_id']['value'] = $my_uniqe_key;
$form['submitted']['my_unique_id']['#value'] = $my_uniqe_key;
$form['my_unique_id']['und']['0']['value']['#value'] = $my_uniqe_key;
$form_state['values']['my_unique_id'] = $my_uniqe_key;
$form_state['values']['my_unique_id']['#value'] = $my_uniqe_key;
$form_state['values']['my_unique_id']['value'] = $my_uniqe_key;
$form_state['my_unique_id']['und']['0']['value']['#value'] = $my_uniqe_key;
$form_state['values']['my_unique_id'][LANGUAGE_NONE][0]['value'] = $my_uniqe_key;
drupal_array_set_nested_value($form, array('submitted', 'my_unique_id', '#value'), $my_uniqe_key;);
form_set_value( array('submitted','my_unique_id'), array(0 => array('value' => $my_uniqe_key;)), $form_state) ;

$cid = $form['#node']->webform['cids']['my_unique_id'];
$form_state['values']['submitted'][$cid] = "static text";

Answer 1

You should use the presave hook provided by webform instead of adding additional submit handlers to the form.

/**
 * Modify a Webform submission, prior to saving it in the database.
 *
 * @param $node
 *   The Webform node on which this submission was made.
 * @param $submission
 *   The Webform submission that is about to be saved to the database.
 */
function hook_webform_submission_presave($node, &$submission) {
  // Update some component's value before it is saved.
  $component_id = 4;
  $submission->data[$component_id][0] = 'foo';
}

This is a lot cleaner than adding custom submit handlers to the form (your custom handler is called after the webform submission handler, which can be a big part of the problem).

You have access to the node object in the presave hook so additional checks can be added beforre altering the component.

Answer 2

I think you should set your value in $form_state['values']['submitted']:

$form_state['values']['submitted'][$cid] = $my_uniqe_key;

Here $cid is the component ID, which is the key of the component info in $form['#node']->webform['components'].

Answer 3

Finally I was able to solve my problem with the help of this answer to an other question. Here is the part of my code from my_custom_submit function, which updates hidden field:

<?php
module_load_include('inc', 'webform', 'includes/webform.submissions');
$node = node_load($form_state['storage']['details']['nid']);
$submission = webform_get_submission($node->nid, $form_state['storage']['details']['sid']);
foreach ($form['#node']->webform['components'] as $key => $component) {
  if ( $component['form_key'] == 'my_unique_id' ){
    $submission->data[$key][0] = $my_uniqe_key;
  }
}
webform_submission_update($node, $submission);

I tried all your suggestions, but non of them worked for me. Thanks for all your efforts!