Processes a form submission.
This function is the heart of form API. The form gets built, validated and in appropriate cases, submitted and rebuilt.
$form_id: The unique string identifying the current form.
$form: An associative array containing the structure of the form.
$form_state: A keyed array containing the current state of the form. This includes the current persistent storage data for the form, and any data passed along by earlier steps when displaying a multi-step form. Additional information, like the sanitized $_POST data, is also accumulated here.
function drupal_process_form($form_id, &$form, &$form_state) {
$form_state['values'] = array();
// With $_GET, these forms are always submitted if requested.
if ($form_state['method'] == 'get' && !empty($form_state['always_process'])) {
if (!isset($form_state['input']['form_build_id'])) {
$form_state['input']['form_build_id'] = $form['#build_id'];
}
if (!isset($form_state['input']['form_id'])) {
$form_state['input']['form_id'] = $form_id;
}
if (!isset($form_state['input']['form_token']) && isset($form['#token'])) {
$form_state['input']['form_token'] = drupal_get_token($form['#token']);
}
}
// form_builder() finishes building the form by calling element #process
// functions and mapping user input, if any, to #value properties, and also
// storing the values in $form_state['values']. We need to retain the
// unprocessed $form in case it needs to be cached.
$unprocessed_form = $form;
$form = form_builder($form_id, $form, $form_state);
// Only process the input if we have a correct form submission.
if ($form_state['process_input']) {
drupal_validate_form($form_id, $form, $form_state);
// drupal_html_id() maintains a cache of element IDs it has seen,
// so it can prevent duplicates. We want to be sure we reset that
// cache when a form is processed, so scenarios that result in
// the form being built behind the scenes and again for the
// browser don't increment all the element IDs needlessly.
if (!form_get_errors()) {
// In case of errors, do not break HTML IDs of other forms.
drupal_static_reset('drupal_html_id');
}
if ($form_state['submitted'] && !form_get_errors() && !$form_state['rebuild']) {
// Execute form submit handlers.
form_execute_handlers('submit', $form, $form_state);
// We'll clear out the cached copies of the form and its stored data
// here, as we've finished with them. The in-memory copies are still
// here, though.
if (!variable_get('cache', 0) && !empty($form_state['values']['form_build_id'])) {
cache_clear_all('form_' . $form_state['values']['form_build_id'], 'cache_form');
cache_clear_all('form_state_' . $form_state['values']['form_build_id'], 'cache_form');
}
// If batches were set in the submit handlers, we process them now,
// possibly ending execution. We make sure we do not react to the batch
// that is already being processed (if a batch operation performs a
// drupal_form_submit).
if (($batch =& batch_get()) && !isset($batch['current_set'])) {
// Store $form_state information in the batch definition.
// We need the full $form_state when either:
// - Some submit handlers were saved to be called during batch
// processing. See form_execute_handlers().
// - The form is multistep.
// In other cases, we only need the information expected by
// drupal_redirect_form().
if ($batch['has_form_submits'] || !empty($form_state['rebuild'])) {
$batch['form_state'] = $form_state;
}
else {
$batch['form_state'] = array_intersect_key($form_state, array_flip(array(
'programmed',
'rebuild',
'storage',
'no_redirect',
'redirect',
)));
}
$batch['progressive'] = !$form_state['programmed'];
batch_process();
// Execution continues only for programmatic forms.
// For 'regular' forms, we get redirected to the batch processing
// page. Form redirection will be handled in _batch_finished(),
// after the batch is processed.
}
// Set a flag to indicate that the form has been processed and executed.
$form_state['executed'] = TRUE;
// Redirect the form based on values in $form_state.
drupal_redirect_form($form_state);
}
// Don't rebuild or cache form submissions invoked via drupal_form_submit().
if (!empty($form_state['programmed'])) {
return;
}
// If $form_state['rebuild'] has been set and input has been processed
// without validation errors, we are in a multi-step workflow that is not
// yet complete. A new $form needs to be constructed based on the changes
// made to $form_state during this request. Normally, a submit handler sets
// $form_state['rebuild'] if a fully executed form requires another step.
// However, for forms that have not been fully executed (e.g., Ajax
// submissions triggered by non-buttons), there is no submit handler to set
// $form_state['rebuild']. It would not make sense to redisplay the
// identical form without an error for the user to correct, so we also
// rebuild error-free non-executed forms, regardless of
// $form_state['rebuild'].
// @todo D8: Simplify this logic; considering Ajax and non-HTML front-ends,
// along with element-level #submit properties, it makes no sense to have
// divergent form execution based on whether the triggering element has
// #executes_submit_callback set to TRUE.
if (($form_state['rebuild'] || !$form_state['executed']) && !form_get_errors()) {
// Form building functions (e.g., _form_builder_handle_input_element())
// may use $form_state['rebuild'] to determine if they are running in the
// context of a rebuild, so ensure it is set.
$form_state['rebuild'] = TRUE;
$form = drupal_rebuild_form($form_id, $form_state, $form);
}
}
// After processing the form, the form builder or a #process callback may
// have set $form_state['cache'] to indicate that the form and form state
// shall be cached. But the form may only be cached if the 'no_cache' property
// is not set to TRUE. Only cache $form as it was prior to form_builder(),
// because form_builder() must run for each request to accommodate new user
// input. Rebuilt forms are not cached here, because drupal_rebuild_form()
// already takes care of that.
if (!$form_state['rebuild'] && $form_state['cache'] && empty($form_state['no_cache'])) {
form_set_cache($form['#build_id'], $unprocessed_form, $form_state);
}
}