form.inc 106 KB
Newer Older
1
<?php
2 3
// $Id$

4
/**
5 6 7 8 9 10
 * @defgroup forms Form builder functions
 * @{
 * Functions that build an abstract representation of a HTML form.
 *
 * All modules should declare their form builder functions to be in this
 * group and each builder function should reference its validate and submit
11
 * functions using \@see. Conversely, validate and submit functions should
12
 * reference the form builder function using \@see. For examples, of this see
13
 * system_modules_uninstall() or user_pass(), the latter of which has the
14 15 16 17 18 19 20 21 22 23 24
 * following in its doxygen documentation:
 *
 * \@ingroup forms
 * \@see user_pass_validate().
 * \@see user_pass_submit().
 *
 * @} End of "defgroup forms".
 */

/**
 * @defgroup form_api Form generation
25
 * @{
26
 * Functions to enable the processing and display of HTML forms.
27
 *
28 29 30 31
 * Drupal uses these functions to achieve consistency in its form processing and
 * presentation, while simplifying code and reducing the amount of HTML that
 * must be explicitly generated by modules.
 *
32
 * The drupal_get_form() function handles retrieving and processing an HTML
33
 * form for modules automatically. For example:
34
 *
35
 * @code
36
 * // Display the user registration form.
37
 * $output = drupal_get_form('user_register');
38
 * @endcode
39 40
 *
 * Forms can also be built and submitted programmatically without any user input
41
 * using the drupal_form_submit() function.
42 43
 *
 * For information on the format of the structured arrays used to define forms,
44
 * and more detailed explanations of the Form API workflow, see the
45 46
 * @link http://api.drupal.org/api/file/developer/topics/forms_api_reference.html reference @endlink
 * and the @link http://api.drupal.org/api/file/developer/topics/forms_api.html quickstart guide. @endlink
47 48 49
 */

/**
50
 * Wrapper for drupal_build_form() for use when $form_state is not needed.
51 52
 *
 * @param $form_id
53 54 55 56 57 58
 *   The unique string identifying the desired form. If a function with that
 *   name exists, it is called to build the form array. Modules that need to
 *   generate the same form (or very similar forms) using different $form_ids
 *   can implement hook_forms(), which maps different $form_id values to the
 *   proper form constructor function. Examples may be found in node_forms(),
 *   search_forms(), and user_forms().
59
 * @param ...
60
 *   Any additional arguments are passed on to the functions called by
61 62 63
 *   drupal_get_form(), including the unique form constructor function. For
 *   example, the node_edit form requires that a node object is passed in here
 *   when it is called.
64
 * @return
65
 *   The form array.
66 67
 *
 * @see drupal_build_form()
68 69
 */
function drupal_get_form($form_id) {
70
  $form_state = array();
71 72

  $args = func_get_args();
73 74 75 76 77 78 79 80
  // Remove $form_id from the arguments.
  array_shift($args);
  $form_state['args'] = $args;

  return drupal_build_form($form_id, $form_state);
}

/**
81
 * Build and process a form based on a form id.
82 83 84
 *
 * The form may also be retrieved from the cache if the form was built in a
 * previous page-load. The form is then passed on for processing, validation
85
 * and submission if there is proper input.
86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130
 *
 * @param $form_id
 *   The unique string identifying the desired form. If a function with that
 *   name exists, it is called to build the form array. Modules that need to
 *   generate the same form (or very similar forms) using different $form_ids
 *   can implement hook_forms(), which maps different $form_id values to the
 *   proper form constructor function. Examples may be found in node_forms(),
 *   search_forms(), and user_forms().
 * @param &$form_state
 *   An array which stores information about the form. This is passed as a
 *   reference so that the caller can use it to examine what the form changed
 *   when the form submission process is complete.
 *
 *   The following parameters may be set in $form_state to affect how the form
 *   is rendered:
 *   - args: An array of arguments to pass to the form builder.
 *   - input: An array of input that corresponds to $_POST or $_GET, depending
 *     on the 'method' chosen (see below).
 *   - method: The HTTP form method to use for finding the input for this form.
 *     May be 'post' or 'get'. Defaults to 'post'. Note that 'get' method
 *     forms do not use form ids so are always considered to be submitted, which
 *     can have unexpected effects. The 'get' method should only be used on
 *     forms that do not change data, as that is exclusively the domain of post.
 *   - no_redirect: If set to TRUE the form will NOT perform a drupal_goto(),
 *     even if a redirect is set.
 *   - always_process: If TRUE and the method is GET, a form_id is not
 *     necessary. This should only be used on RESTful GET forms that do NOT
 *     write data, as this could lead to security issues. It is useful so that
 *     searches do not need to have a form_id in their query arguments to
 *     trigger the search.
 *   - must_validate: Ordinarily, a form is only validated once but there are
 *     times when a form is resubmitted internally and should be validated
 *     again. Setting this to TRUE will force that to happen. This is most
 *     likely to occur during AHAH or AJAX operations.
 * @return
 *   The rendered form or NULL, depending upon the $form_state flags that were set.
 */
function drupal_build_form($form_id, &$form_state) {
  // Ensure some defaults; if already set they will not be overridden.
  $form_state += form_state_defaults();

  if (!isset($form_state['input'])) {
    $form_state['input'] = $form_state['method'] == 'get' ? $_GET : $_POST;
  }

131
  $cacheable = FALSE;
132 133 134 135 136 137 138

  if (isset($_SESSION['batch_form_state'])) {
    // We've been redirected here after a batch processing : the form has
    // already been processed, so we grab the post-process $form_state value
    // and move on to form display. See _batch_finished() function.
    $form_state = $_SESSION['batch_form_state'];
    unset($_SESSION['batch_form_state']);
139 140
  }
  else {
141
    // If the incoming input contains a form_build_id, we'll check the
142 143 144 145
    // cache for a copy of the form in question. If it's there, we don't
    // have to rebuild the form to proceed. In addition, if there is stored
    // form_state data from a previous step, we'll retrieve it so it can
    // be passed on to the form processing code.
146 147
    if (isset($form_state['input']['form_id']) && $form_state['input']['form_id'] == $form_id && !empty($form_state['input']['form_build_id'])) {
      $form = form_get_cache($form_state['input']['form_build_id'], $form_state);
148 149
    }

150 151 152 153
    // If the previous bit of code didn't result in a populated $form
    // object, we're hitting the form for the first time and we need
    // to build it from scratch.
    if (!isset($form)) {
154
      $form = drupal_retrieve_form($form_id, $form_state);
155
      $form_build_id = 'form-' . md5(uniqid(mt_rand(), TRUE));
156
      $form['#build_id'] = $form_build_id;
157 158 159 160 161 162

      // Fix the form method, if it is 'get' in $form_state, but not in $form.
      if ($form_state['method'] == 'get' && !isset($form['#method'])) {
        $form['#method'] = 'get';
      }

163
      drupal_prepare_form($form_id, $form, $form_state);
164 165 166 167
      // Store a copy of the unprocessed form for caching and indicate that it
      // is cacheable if #cache will be set.
      $original_form = $form;
      $cacheable = TRUE;
168
    }
169

170 171 172 173 174 175
    // Now that we know we have a form, we'll process it (validating,
    // submitting, and handling the results returned by its submission
    // handlers. Submit handlers accumulate data in the form_state by
    // altering the $form_state variable, which is passed into them by
    // reference.
    drupal_process_form($form_id, $form, $form_state);
176

177
    if ($cacheable && !empty($form_state['cache']) && empty($form['#no_cache'])) {
178
      // Caching is done past drupal_process_form so #process callbacks can
179 180
      // set #cache.
      form_set_cache($form_build_id, $original_form, $form_state);
181
    }
182 183 184 185 186 187 188 189 190
  }

  // Most simple, single-step forms will be finished by this point --
  // drupal_process_form() usually redirects to another page (or to
  // a 'fresh' copy of the form) once processing is complete. If one
  // of the form's handlers has set $form_state['redirect'] to FALSE,
  // the form will simply be re-rendered with the values still in its
  // fields.
  //
191 192 193 194 195 196 197
  // If $form_state['storage'] or $form_state['rebuild'] has been set
  // and the form has been submitted, we know that we're in a complex
  // multi-part process of some sort and the form's workflow is NOT
  // complete. We need to construct a fresh copy of the form, passing
  // in the latest $form_state in addition to any other variables passed
  // into drupal_get_form().

198
  if ((!empty($form_state['storage']) || $form_state['rebuild']) && $form_state['submitted'] && !form_get_errors()) {
199
    $form = drupal_rebuild_form($form_id, $form_state);
200
  }
201

202 203
  // Don't override #theme if someone already set it.
  if (!isset($form['#theme'])) {
204
    drupal_theme_initialize();
205 206 207 208 209
    $registry = theme_get_registry();
    if (isset($registry[$form_id])) {
      $form['#theme'] = $form_id;
    }
  }
210

211
  return $form;
212
}
213

214 215 216 217 218
/**
 * Retrieve default values for the $form_state array.
 */
function form_state_defaults() {
  return array(
219 220
    'rebuild' => FALSE,
    'redirect' => NULL,
221 222 223
    'storage' => NULL,
    'submitted' => FALSE,
    'programmed' => FALSE,
224 225
    'cache'=> FALSE,
    'method' => 'post',
226
    'groups' => array(),
227 228 229
  );
}

230 231 232 233 234 235 236 237 238 239 240 241 242 243
/**
 * Retrieves a form, caches it and processes it with an empty $_POST.
 *
 * This function clears $_POST and passes the empty $_POST to the form_builder.
 * To preserve some parts from $_POST, pass them in $form_state.
 *
 * If your AHAH callback simulates the pressing of a button, then your AHAH
 * callback will need to do the same as what drupal_get_form would do when the
 * button is pressed: get the form from the cache, run drupal_process_form over
 * it and then if it needs rebuild, run drupal_rebuild_form over it. Then send
 * back a part of the returned form.
 * $form_state['clicked_button']['#array_parents'] will help you to find which
 * part.
 *
244 245 246
 * When getting a form from the cache, the $form_id must be shifted off from
 * $form['#args'], so the resulting array can be given to $form_state['args'].
 *
247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263
 * @param $form_id
 *   The unique string identifying the desired form. If a function
 *   with that name exists, it is called to build the form array.
 *   Modules that need to generate the same form (or very similar forms)
 *   using different $form_ids can implement hook_forms(), which maps
 *   different $form_id values to the proper form constructor function. Examples
 *   may be found in node_forms(), search_forms(), and user_forms().
 * @param $form_state
 *   A keyed array containing the current state of the form. Most
 *   important is the $form_state['storage'] collection.
 * @param $form_build_id
 *   If the AHAH callback calling this function only alters part of the form,
 *   then pass in the existing form_build_id so we can re-cache with the same
 *   csid.
 * @return
 *   The newly built form.
 */
264 265
function drupal_rebuild_form($form_id, &$form_state, $form_build_id = NULL) {
  $form = drupal_retrieve_form($form_id, $form_state);
266 267 268

  if (!isset($form_build_id)) {
    // We need a new build_id for the new version of the form.
269
    $form_build_id = 'form-' . md5(mt_rand());
270 271 272 273
  }
  $form['#build_id'] = $form_build_id;
  drupal_prepare_form($form_id, $form, $form_state);

274 275 276 277 278 279
  if (empty($form['#no_cache'])) {
    // We cache the form structure so it can be retrieved later for validation.
    // If $form_state['storage'] is populated, we also cache it so that it can
    // be used to resume complex multi-step processes.
    form_set_cache($form_build_id, $form, $form_state);
  }
280 281 282 283

  // Clear out all post data, as we don't want the previous step's
  // data to pollute this one and trigger validate/submit handling,
  // then process the form for rendering.
284 285
  $form_state['input'] = array();

286 287 288 289
  // Also clear out all group associations as these might be different
  // when rerendering the form.
  $form_state['groups'] = array();

290 291 292
  // Do not call drupal_process_form(), since it would prevent the rebuilt form
  // to submit.
  $form = form_builder($form_id, $form, $form_state);
293 294 295
  return $form;
}

296 297 298 299
/**
 * Fetch a form from cache.
 */
function form_get_cache($form_build_id, &$form_state) {
300
  if ($cached = cache_get('form_' . $form_build_id, 'cache_form')) {
301
    $form = $cached->data;
302 303 304 305 306 307
    global $user;
    if ((isset($form['#cache_token']) && drupal_valid_token($form['#cache_token'])) || (!isset($form['#cache_token']) && !$user->uid)) {
      if ($cached = cache_get('storage_' . $form_build_id, 'cache_form')) {
        $form_state['storage'] = $cached->data;
      }
      return $form;
308 309 310 311 312 313 314 315
    }
  }
}

/**
 * Store a form in the cache
 */
function form_set_cache($form_build_id, $form, $form_state) {
316 317
  // 6 hours cache life time for forms should be plenty.
  $expire = 21600;
318 319 320 321
  global $user;
  if ($user->uid) {
    $form['#cache_token'] = drupal_get_token();
  }
322
  cache_set('form_' . $form_build_id, $form, 'cache_form', REQUEST_TIME + $expire);
323
  if (!empty($form_state['storage'])) {
324
    cache_set('storage_' . $form_build_id, $form_state['storage'], 'cache_form', REQUEST_TIME + $expire);
325 326 327
  }
}

328
/**
329
 * Retrieves a form using a form_id, populates it with $form_state['values'],
330 331 332 333 334 335 336 337
 * processes it, and returns any validation errors encountered. This
 * function is the programmatic counterpart to drupal_get_form().
 *
 * @param $form_id
 *   The unique string identifying the desired form. If a function
 *   with that name exists, it is called to build the form array.
 *   Modules that need to generate the same form (or very similar forms)
 *   using different $form_ids can implement hook_forms(), which maps
338
 *   different $form_id values to the proper form constructor function. Examples
339
 *   may be found in node_forms(), search_forms(), and user_forms().
340 341 342 343 344
 * @param $form_state
 *   A keyed array containing the current state of the form. Most
 *   important is the $form_state['values'] collection, a tree of data
 *   used to simulate the incoming $_POST information from a user's
 *   form submission.
345
 * @param ...
346
 *   Any additional arguments are passed on to the functions called by
347
 *   drupal_form_submit(), including the unique form constructor function.
348 349
 *   For example, the node_edit form requires that a node object be passed
 *   in here when it is called.
350 351
 * For example:
 *
352
 * @code
353
 * // register a new user
354 355 356 357
 * $form_state = array();
 * $form_state['values']['name'] = 'robo-user';
 * $form_state['values']['mail'] = 'robouser@example.com';
 * $form_state['values']['pass'] = 'password';
358
 * $form_state['values']['op'] = t('Create new account');
359
 * drupal_form_submit('user_register', $form_state);
360 361
 *
 * // Create a new node
362
 * $form_state = array();
363
 * module_load_include('inc', 'node', 'node.pages');
364
 * $node = array('type' => 'story');
365 366 367
 * $form_state['values']['title'] = 'My node';
 * $form_state['values']['body'] = 'This is the body text!';
 * $form_state['values']['name'] = 'robo-user';
368
 * $form_state['values']['op'] = t('Save');
369
 * drupal_form_submit('story_node_form', $form_state, (object)$node);
370
 * @endcode
371
 */
372
function drupal_form_submit($form_id, &$form_state) {
373 374 375 376 377 378
  if (!isset($form_state['args'])) {
    $args = func_get_args();
    array_shift($args);
    array_shift($args);
    $form_state['args'] = $args;
  }
Dries's avatar
Dries committed
379

380 381 382
  $form = drupal_retrieve_form($form_id, $form_state);
  $form_state['input'] = $form_state['values'];
  $form_state['programmed'] = TRUE;
383 384
  // Programmed forms are always submitted.
  $form_state['submitted'] = TRUE;
385 386
  // Merge in default values.
  $form_state += form_state_defaults();
387

388 389
  drupal_prepare_form($form_id, $form, $form_state);
  drupal_process_form($form_id, $form, $form_state);
390 391
}

392 393 394 395 396 397 398 399
/**
 * Retrieves the structured array that defines a given form.
 *
 * @param $form_id
 *   The unique string identifying the desired form. If a function
 *   with that name exists, it is called to build the form array.
 *   Modules that need to generate the same form (or very similar forms)
 *   using different $form_ids can implement hook_forms(), which maps
400
 *   different $form_id values to the proper form constructor function.
401 402
 * @param $form_state
 *   A keyed array containing the current state of the form.
403
 * @param ...
404 405
 *   Any additional arguments needed by the unique form constructor
 *   function. Generally, these are any arguments passed into the
406
 *   drupal_get_form() or drupal_form_submit() functions after the first
407 408 409
 *   argument. If a module implements hook_forms(), it can examine
 *   these additional arguments and conditionally return different
 *   builder functions as well.
410
 */
411
function drupal_retrieve_form($form_id, &$form_state) {
412
  $forms = &drupal_static(__FUNCTION__);
413

414
  // We save two copies of the incoming arguments: one for modules to use
415
  // when mapping form ids to constructor functions, and another to pass to
416 417
  // the constructor function itself.
  $args = $form_state['args'];
418 419 420

  // We first check to see if there's a function named after the $form_id.
  // If there is, we simply pass the arguments on to it to get the form.
421
  if (!function_exists($form_id)) {
422
    // In cases where many form_ids need to share a central constructor function,
423
    // such as the node editing form, modules can implement hook_forms(). It
424
    // maps one or more form_ids to the correct constructor functions.
425 426 427 428 429 430 431 432 433
    //
    // We cache the results of that hook to save time, but that only works
    // for modules that know all their form_ids in advance. (A module that
    // adds a small 'rate this comment' form to each comment in a list
    // would need a unique form_id for each one, for example.)
    //
    // So, we call the hook if $forms isn't yet populated, OR if it doesn't
    // yet have an entry for the requested form_id.
    if (!isset($forms) || !isset($forms[$form_id])) {
434
      $forms = module_invoke_all('forms', $form_id, $args);
435 436 437 438 439 440 441 442 443
    }
    $form_definition = $forms[$form_id];
    if (isset($form_definition['callback arguments'])) {
      $args = array_merge($form_definition['callback arguments'], $args);
    }
    if (isset($form_definition['callback'])) {
      $callback = $form_definition['callback'];
    }
  }
444

445 446 447
 // We need to pass $form_state by reference in order for forms to modify it,
 // since call_user_func_array() requires that referenced variables be passed
 // explicitly.
448
  $args = array_merge(array(&$form_state), $args);
449

450 451
  // If $callback was returned by a hook_forms() implementation, call it.
  // Otherwise, call the function named after the form id.
452
  $form = call_user_func_array(isset($callback) ? $callback : $form_id, $args);
453 454
  $form['#form_id'] = $form_id;
  $form['#args'] = $form_state['args'];
455
  return $form;
456 457 458 459 460 461 462 463
}

/**
 * This function is the heart of form API. The form gets built, validated and in
 * appropriate cases, submitted.
 *
 * @param $form_id
 *   The unique string identifying the current form.
464 465
 * @param $form
 *   An associative array containing the structure of the form.
466 467
 * @param $form_state
 *   A keyed array containing the current state of the form. This
Dries's avatar
Dries committed
468
 *   includes the current persistent storage data for the form, and
469 470 471
 *   any data passed along by earlier steps when displaying a
 *   multi-step form. Additional information, like the sanitized $_POST
 *   data, is also accumulated here.
472
 */
473 474 475
function drupal_process_form($form_id, &$form, &$form_state) {
  $form_state['values'] = array();

476 477 478 479 480 481 482 483 484 485 486 487 488
  // 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']);
    }
  }

489
  // Build the form.
490
  $form = form_builder($form_id, $form, $form_state);
491 492 493

  // Only process the input if we have a correct form submission.
  if ($form_state['process_input']) {
494 495
    drupal_validate_form($form_id, $form, $form_state);

496 497
    // form_clean_id() maintains a cache of element IDs it has seen,
    // so it can prevent duplicates. We want to be sure we reset that
498
    // cache when a form is processed, so scenarios that result in
499 500
    // the form being built behind the scenes and again for the
    // browser don't increment all the element IDs needlessly.
501
    drupal_static_reset('form_clean_id');
502

503 504
    if ($form_state['submitted'] && !form_get_errors() && !$form_state['rebuild']) {
      // Execute form submit handlers.
505 506 507 508 509
      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.
510
      if (variable_get('cache', CACHE_DISABLED) == CACHE_DISABLED && !empty($form_state['values']['form_build_id'])) {
511 512
        cache_clear_all('form_' . $form_state['values']['form_build_id'], 'cache_form');
        cache_clear_all('storage_' . $form_state['values']['form_build_id'], 'cache_form');
513 514 515
      }

      // If batches were set in the submit handlers, we process them now,
516 517
      // possibly ending execution. We make sure we do not react to the batch
      // that is already being processed (if a batch operation performs a
518
      // drupal_form_submit).
519
      if ($batch =& batch_get() && !isset($batch['current_set'])) {
520
        // The batch uses its own copies of $form and $form_state for
521
        // late execution of submit handlers and post-batch redirection.
522 523
        $batch['form'] = $form;
        $batch['form_state'] = $form_state;
524
        $batch['progressive'] = !$form_state['programmed'];
525
        batch_process();
526 527 528 529
        // 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.
530
      }
531

532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547
      // Set a flag to indicate the the form has been processed and executed.
      $form_state['executed'] = TRUE;

      // The form is executed. By default, we're finished now and redirect to a
      // new destination page. The path of the destination page can be set in
      // $form['#redirect'] or $form_state['redirect']. If neither of the two is
      // set, the user is redirect to the current page, which means a fresh,
      // unpopulated copy of the form.
      // Redirection is skipped, though, if
      // - the form was called by drupal_form_submit(),
      // - the form has to be rebuilt because either $form_state['rebuild'] was
      //   set to TRUE or $form_state['storage'] was populated by a submit handler.
      // - $form_state['no_redirect'] is set to TRUE,
      // - $form_state['redirect'] or $form['#redirect'] is set to FALSE.
      if (!$form_state['programmed'] && empty($form_state['rebuild']) && empty($form_state['storage']) && empty($form_state['no_redirect'])) {
        drupal_redirect_form($form, $form_state['redirect']);
548
      }
549 550 551 552 553 554 555 556 557 558 559 560 561 562
    }
  }
}

/**
 * Prepares a structured form array by adding required elements,
 * executing any hook_form_alter functions, and optionally inserting
 * a validation token to prevent tampering.
 *
 * @param $form_id
 *   A unique string identifying the form for validation, submission,
 *   theming, and hook_form_alter functions.
 * @param $form
 *   An associative array containing the structure of the form.
563 564 565
 * @param $form_state
 *   A keyed array containing the current state of the form. Passed
 *   in here so that hook_form_alter() calls can use it, as well.
566
 */
567
function drupal_prepare_form($form_id, &$form, &$form_state) {
568 569
  global $user;

570
  $form['#type'] = 'form';
571
  $form_state['programmed'] = isset($form_state['programmed']) ? $form_state['programmed'] : FALSE;
572

573 574 575 576 577 578 579 580 581
  if (isset($form['#build_id'])) {
    $form['form_build_id'] = array(
      '#type' => 'hidden',
      '#value' => $form['#build_id'],
      '#id' => $form['#build_id'],
      '#name' => 'form_build_id',
    );
  }

582 583 584 585
  // Add a token, based on either #token or form_id, to any form displayed to
  // authenticated users. This ensures that any submitted form was actually
  // requested previously by the user and protects against cross site request
  // forgeries.
586
  if (isset($form['#token'])) {
587
    if ($form['#token'] === FALSE || $user->uid == 0 || $form_state['programmed']) {
588
      unset($form['#token']);
589
    }
590
    else {
591
      $form['form_token'] = array('#type' => 'token', '#default_value' => drupal_get_token($form['#token']));
592
    }
593
  }
594
  elseif (isset($user->uid) && $user->uid && !$form_state['programmed']) {
595 596
    $form['#token'] = $form_id;
    $form['form_token'] = array(
597
      '#id' => form_clean_id('edit-' . $form_id . '-form-token'),
598 599 600 601 602
      '#type' => 'token',
      '#default_value' => drupal_get_token($form['#token']),
    );
  }

603
  if (isset($form_id)) {
604 605 606 607 608
    $form['form_id'] = array(
      '#type' => 'hidden',
      '#value' => $form_id,
      '#id' => form_clean_id("edit-$form_id"),
    );
609
  }
610
  if (!isset($form['#id'])) {
611
    $form['#id'] = form_clean_id($form_id);
612
  }
613

614
  $form += element_info('form');
615
  $form += array('#tree' => FALSE, '#parents' => array());
616

Dries's avatar
Dries committed
617
  if (!isset($form['#validate'])) {
618
    if (function_exists($form_id . '_validate')) {
619
      $form['#validate'] = array($form_id . '_validate');
Dries's avatar
Dries committed
620 621 622
    }
  }

623
  if (!isset($form['#submit'])) {
624
    if (function_exists($form_id . '_submit')) {
625
      // We set submit here so that it can be altered.
626
      $form['#submit'] = array($form_id . '_submit');
Dries's avatar
Dries committed
627 628 629
    }
  }

630 631 632 633 634 635 636 637
  // Normally, we would call drupal_alter($form_id, $form, $form_state).
  // However, drupal_alter() normally supports just one byref parameter. Using
  // the __drupal_alter_by_ref key, we can store any additional parameters
  // that need to be altered, and they'll be split out into additional params
  // for the hook_form_alter() implementations.
  // @todo: Remove this in Drupal 7.
  $data = &$form;
  $data['__drupal_alter_by_ref'] = array(&$form_state);
638
  drupal_alter('form_' . $form_id, $data);
639 640 641 642 643

  // __drupal_alter_by_ref is unset in the drupal_alter() function, we need
  // to repopulate it to ensure both calls get the data.
  $data['__drupal_alter_by_ref'] = array(&$form_state);
  drupal_alter('form', $data, $form_id);
644 645
}

646 647

/**
648
 * Validates user-submitted form data from the $form_state using
649 650 651 652 653 654 655
 * the validate functions defined in a structured form array.
 *
 * @param $form_id
 *   A unique string identifying the form for validation, submission,
 *   theming, and hook_form_alter functions.
 * @param $form
 *   An associative array containing the structure of the form.
656 657 658 659 660 661 662 663 664 665
 * @param $form_state
 *   A keyed array containing the current state of the form. The current
 *   user-submitted data is stored in $form_state['values'], though
 *   form validation functions are passed an explicit copy of the
 *   values for the sake of simplicity. Validation handlers can also
 *   $form_state to pass information on to submit handlers. For example:
 *     $form_state['data_for_submision'] = $data;
 *   This technique is useful when validation requires file parsing,
 *   web service requests, or other expensive requests that should
 *   not be repeated in the submission step.
666
 */
667
function drupal_validate_form($form_id, $form, &$form_state) {
668
  $validated_forms = &drupal_static(__FUNCTION__, array());
669

670
  if (isset($validated_forms[$form_id]) && empty($form_state['must_validate'])) {
671 672
    return;
  }
673

674
  // If the session token was set by drupal_prepare_form(), ensure that it
675
  // matches the current user's session.
676
  if (isset($form['#token'])) {
677
    if (!drupal_valid_token($form_state['values']['form_token'], $form['#token'])) {
678
      // Setting this error will cause the form to fail validation.
679
      form_set_error('form_token', t('Validation error, please try again. If this error persists, please contact the site administrator.'));
680 681 682
    }
  }

683
  _form_validate($form, $form_state, $form_id);
684
  $validated_forms[$form_id] = TRUE;
685 686
}

687 688 689 690 691 692
/**
 * Redirect the user to a URL after a form has been processed.
 *
 * @param $form
 *   An associative array containing the structure of the form.
 * @param $redirect
693
 *   An optional value containing the destination path to redirect
694 695 696
 *   to if none is specified by the form.
 */
function drupal_redirect_form($form, $redirect = NULL) {
697
  $goto = NULL;
698 699 700
  if (isset($redirect)) {
    $goto = $redirect;
  }
701
  if ($goto !== FALSE && isset($form['#redirect'])) {
702 703
    $goto = $form['#redirect'];
  }
704 705 706 707 708 709
  if (!isset($goto) || ($goto !== FALSE)) {
    if (isset($goto)) {
      if (is_array($goto)) {
        call_user_func_array('drupal_goto', $goto);
      }
      else {
710 711 712 713 714
        // This function can be called from the installer, which guarantees
        // that $redirect will always be a string, so catch that case here
        // and use the appropriate redirect function.
        $function = drupal_installation_attempted() ? 'install_goto' : 'drupal_goto';
        $function($goto);
715 716 717 718
      }
    }
    drupal_goto($_GET['q']);
  }
719 720
}

721 722 723 724 725 726 727
/**
 * Performs validation on form elements. First ensures required fields are
 * completed, #maxlength is not exceeded, and selected options were in the
 * list of options given to the user. Then calls user-defined validators.
 *
 * @param $elements
 *   An associative array containing the structure of the form.
728 729 730 731 732 733 734 735 736 737
 * @param $form_state
 *   A keyed array containing the current state of the form. The current
 *   user-submitted data is stored in $form_state['values'], though
 *   form validation functions are passed an explicit copy of the
 *   values for the sake of simplicity. Validation handlers can also
 *   $form_state to pass information on to submit handlers. For example:
 *     $form_state['data_for_submision'] = $data;
 *   This technique is useful when validation requires file parsing,
 *   web service requests, or other expensive requests that should
 *   not be repeated in the submission step.
738 739 740 741
 * @param $form_id
 *   A unique string identifying the form for validation, submission,
 *   theming, and hook_form_alter functions.
 */
742
function _form_validate($elements, &$form_state, $form_id = NULL) {
743 744
  // Also used in the installer, pre-database setup.
  $t = get_t();
745

746 747 748
  // Recurse through all children.
  foreach (element_children($elements) as $key) {
    if (isset($elements[$key]) && $elements[$key]) {
749
      _form_validate($elements[$key], $form_state);
750 751
    }
  }
752
  // Validate the current input.
753
  if (!isset($elements['#validated']) || !$elements['#validated']) {
754
    if (isset($elements['#needs_validation'])) {
755 756 757 758 759
      // Make sure a value is passed when the field is required.
      // A simple call to empty() will not cut it here as some fields, like
      // checkboxes, can return a valid value of '0'. Instead, check the
      // length if it's a string, and the item count if it's an array.
      if ($elements['#required'] && (!count($elements['#value']) || (is_string($elements['#value']) && strlen(trim($elements['#value'])) == 0))) {
760
        form_error($elements, $t('!name field is required.', array('!name' => $elements['#title'])));
761
      }
762

763 764
      // Verify that the value is not longer than #maxlength.
      if (isset($elements['#maxlength']) && drupal_strlen($elements['#value']) > $elements['#maxlength']) {
765
        form_error($elements, $t('!name cannot be longer than %max characters but is currently %length characters long.', array('!name' => empty($elements['#title']) ? $elements['#parents'][0] : $elements['#title'], '%max' => $elements['#maxlength'], '%length' => drupal_strlen($elements['#value']))));
766 767
      }

768
      if (isset($elements['#options']) && isset($elements['#value'])) {
769 770 771 772 773 774 775 776 777 778
        if ($elements['#type'] == 'select') {
          $options = form_options_flatten($elements['#options']);
        }
        else {
          $options = $elements['#options'];
        }
        if (is_array($elements['#value'])) {
          $value = $elements['#type'] == 'checkboxes' ? array_keys(array_filter($elements['#value'])) : $elements['#value'];
          foreach ($value as $v) {
            if (!isset($options[$v])) {
779
              form_error($elements, $t('An illegal choice has been detected. Please contact the site administrator.'));
780
              watchdog('form', 'Illegal choice %choice in !name element.', array('%choice' => $v, '!name' => empty($elements['#title']) ? $elements['#parents'][0] : $elements['#title']), WATCHDOG_ERROR);
781
            }
782 783
          }
        }
784
        elseif (!isset($options[$elements['#value']])) {
785
          form_error($elements, $t('An illegal choice has been detected. Please contact the site administrator.'));
786
          watchdog('form', 'Illegal choice %choice in %name element.', array('%choice' => $elements['#value'], '%name' => empty($elements['#title']) ? $elements['#parents'][0] : $elements['#title']), WATCHDOG_ERROR);
787
        }
788 789 790
      }
    }

791
    // Call user-defined form level validators.
792 793 794 795 796 797 798
    if (isset($form_id)) {
      form_execute_handlers('validate', $elements, $form_state);
    }
    // Call any element-specific validators. These must act on the element
    // #value data.
    elseif (isset($elements['#element_validate'])) {
      foreach ($elements['#element_validate'] as $function) {
799
        if (function_exists($function))  {
800
          $function($elements, $form_state, $form_state['complete form']);
801 802 803
        }
      }
    }
804
    $elements['#validated'] = TRUE;
805 806 807
  }
}

808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824
/**
 * A helper function used to execute custom validation and submission
 * handlers for a given form. Button-specific handlers are checked
 * first. If none exist, the function falls back to form-level handlers.
 *
 * @param $type
 *   The type of handler to execute. 'validate' or 'submit' are the
 *   defaults used by Form API.
 * @param $form
 *   An associative array containing the structure of the form.
 * @param $form_state
 *   A keyed array containing the current state of the form. If the user
 *   submitted the form by clicking a button with custom handler functions
 *   defined, those handlers will be stored here.
 */
function form_execute_handlers($type, &$form, &$form_state) {
  $return = FALSE;
825 826
  if (isset($form_state[$type . '_handlers'])) {
    $handlers = $form_state[$type . '_handlers'];
827
  }
828 829
  elseif (isset($form['#' . $type])) {
    $handlers = $form['#' . $type];
830 831 832 833 834 835
  }
  else {
    $handlers = array();
  }

  foreach ($handlers as $function) {
836
    if (function_exists($function))  {
837 838
      // Check to see if a previous _submit handler has set a batch, but
      // make sure we do not react to a batch that is already being processed
839
      // (for instance if a batch operation performs a drupal_form_submit()).
840
      if ($type == 'submit' && ($batch =& batch_get()) && !isset($batch['current_set'])) {
841 842 843
        // Some previous _submit handler has set a batch. We store the call
        // in a special 'control' batch set, for execution at the correct
        // time during the batch processing workflow.
844
        $batch['sets'][] = array('form_submit' => $function);
845 846
      }
      else {
847
        $function($form, $form_state);
848 849 850 851 852 853 854
      }
      $return = TRUE;
    }
  }
  return $return;
}

855
/**
856 857 858 859 860 861 862 863 864
 * File an error against a form element.
 *
 * @param $name
 *   The name of the form element. If the #parents property of your form
 *   element is array('foo', 'bar', 'baz') then you may set an error on 'foo'
 *   or 'foo][bar][baz'. Setting an error on 'foo' sets an error for every
 *   element where the #parents array starts with 'foo'.
 * @param $message
 *   The error message to present to the user.
865 866
 * @param $reset
 *   Reset the form errors static cache.
867 868 869
 * @return
 *   Never use the return value of this function, use form_get_errors and
 *   form_get_error instead.
870
 */
871 872
function form_set_error($name = NULL, $message = '') {
  $form = &drupal_static(__FUNCTION__, array());
873 874
  if (isset($name) && !isset($form[$name])) {
    $form[$name] = $message;
875 876 877
    if ($message) {
      drupal_set_message($message, 'error');
    }
878 879 880 881
  }
  return $form;
}

882 883 884 885 886 887 888
/**
 * Clear all errors against all form elements made by form_set_error().
 */
function form_clear_error() {
  drupal_static_reset('form_set_error');
}

889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913
/**
 * Return an associative array of all errors.
 */
function form_get_errors() {
  $form = form_set_error();
  if (!empty($form)) {
    return $form;
  }
}

/**
 * Return the error message filed against the form with the specified name.
 */
function form_get_error($element) {
  $form = form_set_error();
  $key = $element['#parents'][0];
  if (isset($form[$key])) {
    return $form[$key];
  }
  $key = implode('][', $element['#parents']);
  if (isset($form[$key])) {
    return $form[$key];
  }
}

914 915 916
/**
 * Flag an element as having an error.
 */
917
function form_error(&$element, $message = '') {
918
  form_set_error(implode('][', $element['#parents']), $message);
919 920 921
}

/**
922
 * Walk through the structured form array, adding any required
923
 * properties to each element and mapping the incoming input
924 925
 * data to the proper elements. Also, execute any #process handlers
 * attached to a specific element.
926 927
 *
 * @param $form_id
928 929
 *   A unique string identifying the form for validation, submission,
 *   theming, and hook_form_alter functions.
930 931
 * @param $element
 *   An associative array containing the structure of the current element.
932 933 934 935 936
 * @param $form_state
 *   A keyed array containing the current state of the form. In this
 *   context, it is used to accumulate information about which button
 *   was clicked when the form was submitted, as well as the sanitized
 *   $_POST data.
937
 */
938
function form_builder($form_id, $element, &$form_state) {
939
  // Initialize as unprocessed.
940
  $element['#processed'] = FALSE;
941

942
  // Use element defaults.
943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960
  if ((!empty($element['#type'])) && ($info = element_info($element['#type']))) {
    // Overlay $info onto $element, retaining preexisting keys in $element.
    $element += $info;
    $element['#defaults_loaded'] = TRUE;
  }

  // Special handling if we're on the top level form element.
  if (isset($element['#type']) && $element['#type'] == 'form') {
    // Store a complete copy of the form in form_state prior to building the form.
    $form_state['complete form'] = $element;
    // Set a flag if we have a correct form submission. This is always TRUE for
    // programmed forms coming from drupal_form_submit(), or if the form_id coming
    // from the POST data is set and matches the current form_id.
    if ($form_state['programmed'] || (!empty($form_state['input']) && (isset($form_state['input']['form_id']) && ($form_state['input']['form_id'] == $form_id)))) {
      $form_state['process_input'] = TRUE;
    }
    else {
      $form_state['process_input'] = FALSE;
961
    }
962 963
  }

964 965
  if (!isset($element['#id'])) {
    $element['#id'] = form_clean_id('edit-' . implode('-', $element['#parents']));
966
  }
967 968 969
  // Handle input elements.
  if (!empty($element['#input'])) {
    _form_builder_handle_input_element($form_id, $element, $form_state);
970
  }
971 972
  // Allow for elements to expand to multiple elements, e.g., radios,
  // checkboxes and files.
973 974
  if (isset($element['#process']) && !$element['#processed']) {
    foreach ($element['#process'] as $process) {
975
      if (function_exists($process)) {
976
        $element = $process($element, $form_state, $form_state['complete form']);
977 978
      }
    }
979
    $element['#processed'] = TRUE;
980
  }
981

982
  // We start off assuming all form elements are in the correct order.
983
  $element['#sorted'] = TRUE;
984

985
  // Recurse through all child elements.
986
  $count = 0;
987
  foreach (element_children($element) as $key) {
988
    // Don't squash an existing tree value.
989 990
    if (!isset($element[$key]['#tree'])) {
      $element[$key]['#tree'] = $element['#tree'];
991
    }
992

993
    // Deny access to child elements if parent is denied.
994 995
    if (isset($element['#access']) && !$element['#access']) {
      $element[$key]['#access'] = FALSE;
996 997
    }

998
    // Don't squash existing parents value.
999
    if (!isset($element[$key]['#parents'])) {
1000 1001
      // Check to see if a tree of child elements is present. If so,
      // continue down the tree if required.
1002 1003
      $element[$key]['#parents'] = $element[$key]['#tree'] && $element['#tree'] ? array_merge($element['#parents'], array($key)) : array($key);
      $array_parents = isset($element['#array_parents']) ? $element['#array_parents'] : array();
1004
      $array_parents[] = $key;
1005
      $element[$key]['#array_parents'] = $array_parents;
1006 1007
    }

1008
    // Assign a decimal placeholder weight to preserve original array order.
1009 1010
    if (!isset($element[$key]['#weight'])) {
      $element[$key]['#weight'] = $count/1000;
1011
    }
1012
    else {
1013 1014
      // If one of the child elements has a weight then we will need to sort
      // later.
1015
      unset($element['#sorted']);
1016
    }
1017
    $element[$key] = form_builder($form_id, $element[$key], $form_state);
1018 1019 1020
    $count++;
  }

1021 1022
  // The #after_build flag allows any piece of a form to be altered
  // after normal input parsing has been completed.
1023 1024 1025 1026
  if (isset($element['#after_build']) && !isset($element['#after_build_done'])) {
    foreach ($element['#after_build'] as $function) {
      $element = $function($element, $form_state);
      $element['#after_build_done'] = TRUE;
1027 1028 1029 1030
    }
  }

  // Now that we've processed everything, we can go back to handle the funky
Dries's avatar
Dries committed
1031
  // Internet Explorer button-click scenario.
1032
  _form_builder_ie_cleanup($element, $form_state);
1033

1034
  // We should keep the buttons array until the IE clean up function
1035 1036 1037 1038 1039 1040
  // has recognized the submit button so the form has been marked
  // as submitted. If we already know which button was submitted,
  // we don't need the array.
  if (!empty($form_state['submitted'])) {
    unset($form_state['buttons']);
  }
1041

1042
  // If some callback set #cache, we need to flip a flag so later it
1043
  // can be found.
1044 1045
  if (!empty($element['#cache'])) {
    $form_state['cache'] = $element['#cache'];
1046
  }
1047 1048

  // If there is a file element, we need to flip a flag so later the
1049
  // form encoding can be set.
1050 1051
  if (isset($element['#type']) && $element['#type'] == 'file') {
    $form_state['has_file_element'] = TRUE;
1052
  }
1053 1054 1055

  if (isset($element['#type']) && $element['#type'] == 'form') {
    // We are on the top form.
1056
    // If there is a file element, we set the form encoding.
1057 1058
    if (isset($form_state['has_file_element'])) {
      $element['#attributes']['enctype'] = 'multipart/form-data';
1059
    }
1060 1061
    // Update the copy of the complete form for usage in validation handlers.
    $form_state['complete form'] = $element;
1062
  }
1063
  return $element;
1064 1065 1066 1067
}

/**
 * Populate the #value and #name properties of input elements so they
1068
 * can be processed and rendered.
1069
 */
1070 1071 1072 1073 1074
function _form_builder_handle_input_element($form_id, &$element, &$form_state) {
  if (!isset($element['#name'])) {
    $name = array_shift($element['#parents']);
    $element['#name'] = $name;
    if ($element['#type'] == 'file') {
1075 1076 1077
      // To make it easier to handle $_FILES in file.inc, we place all
      // file fields in the 'files' array. Also, we do not support
      // nested file names.
1078
      $element['#name'] = 'files[' . $element['#name'] . ']';
1079
    }
1080 1081
    elseif (count($element['#parents'])) {
      $element['#name'] .= '[' . implode('][', $element['#parents']) . ']';
1082
    }
1083
    array_unshift($element['#parents'], $name);
1084 1085
  }

1086 1087
  if (!empty($element['#disabled'])) {
    $element['#attributes']['disabled'] = 'disabled';
1088 1089
  }

1090 1091 1092 1093 1094 1095 1096 1097
  // Set the element's #value property.
  if (!isset($element['#value']) && !array_key_exists('#value', $element)) {
    $value_callback = !empty($element['#value_callback']) ? $element['#value_callback'] : 'form_type_' . $element['#type'] . '_value';

    if ($form_state['programmed'] || ($form_state['process_input'] && (!isset($element['#access']) || $element['#access']))) {
      $input = $form_state['input'];
      foreach ($element['#parents'] as $parent) {
        $input = isset($input[$parent]) ? $input[$parent] : NULL;
1098
      }
1099 1100
      // If we have input for the current element, assign it to the #value property.
      if (!$form_state['programmed'] || isset($input)) {
1101
        // Call #type_value to set the form value;
1102
        if (function_exists($value_callback)) {
1103
          $element['#value'] = $value_callback($element, $input, $form_state);
1104
        }
1105 1106
        if (!isset($element['#value']) && isset($input)) {
          $element['#value'] = $input;
1107 1108
        }
      }
1109
      // Mark all posted values for validation.
1110 1111
      if (isset($element['#value']) || (!empty($element['#required']))) {
        $element['#needs_validation'] = TRUE;
1112
      }
Dries's avatar