1 <?php

     2 // $Id: batch.inc,v 1.14 2007/12/20 11:57:20 goba Exp $

     3 

     4 /**

     5  * @file Batch processing API for processes to run in multiple HTTP requests.

     6  */

     7 

     8 /**

     9  * State-based dispatcher for the batch processing page.

    10  */

    11 function _batch_page() {

    12   $batch =& batch_get();

    13 

    14   // Retrieve the current state of batch from db.

    15   if (isset($_REQUEST['id']) && $data = db_result(db_query("SELECT batch FROM {batch} WHERE bid = %d AND token = '%s'", $_REQUEST['id'], drupal_get_token($_REQUEST['id'])))) {

    16     $batch = unserialize($data);

    17   }

    18   else {

    19     return FALSE;

    20   }

    21 

    22   // Register database update for end of processing.

    23   register_shutdown_function('_batch_shutdown');

    24 

    25   $op = isset($_REQUEST['op']) ? $_REQUEST['op'] : '';

    26   $output = NULL;

    27   switch ($op) {

    28     case 'start':

    29       $output = _batch_start();

    30       break;

    31 

    32     case 'do':

    33       // JS-version AJAX callback.

    34       _batch_do();

    35       break;

    36 

    37     case 'do_nojs':

    38       // Non-JS progress page.

    39       $output = _batch_progress_page_nojs();

    40       break;

    41 

    42     case 'finished':

    43       $output = _batch_finished();

    44       break;

    45   }

    46 

    47   return $output;

    48 }

    49 

    50 /**

    51  * Initiate the batch processing

    52  */

    53 function _batch_start() {

    54   // Choose between the JS and non-JS version.

    55   // JS-enabled users are identified through the 'has_js' cookie set in drupal.js.

    56   // If the user did not visit any JS enabled page during his browser session,

    57   // he gets the non-JS version...

    58   if (isset($_COOKIE['has_js']) && $_COOKIE['has_js']) {

    59     return _batch_progress_page_js();

    60   }

    61   else {

    62     return _batch_progress_page_nojs();

    63   }

    64 }

    65 

    66 /**

    67  * Batch processing page with JavaScript support.

    68  */

    69 function _batch_progress_page_js() {

    70   $batch = batch_get();

    71 

    72   // The first batch set gets to set the page title

    73   // and the initialization and error messages.

    74   $current_set = _batch_current_set();

    75   drupal_set_title($current_set['title']);

    76   drupal_add_js('misc/progress.js', 'core', 'header', FALSE, FALSE);

    77 

    78   $url = url($batch['url'], array('query' => array('id' => $batch['id'])));

    79   $js_setting = array(

    80     'batch' => array(

    81       'errorMessage' => $current_set['error_message'] .'<br/>'. $batch['error_message'],

    82       'initMessage' => $current_set['init_message'],

    83       'uri' => $url,

    84     ),

    85   );

    86   drupal_add_js($js_setting, 'setting');

    87   drupal_add_js('misc/batch.js', 'core', 'header', FALSE, FALSE);

    88 

    89   $output = '<div id="progress"></div>';

    90   return $output;

    91 }

    92 

    93 /**

    94  * Do one pass of execution and inform back the browser about progression

    95  * (used for JavaScript-mode only).

    96  */

    97 function _batch_do() {

    98   // HTTP POST required

    99   if ($_SERVER['REQUEST_METHOD'] != 'POST') {

   100     drupal_set_message(t('HTTP POST is required.'), 'error');

   101     drupal_set_title(t('Error'));

   102     return '';

   103   }

   104 

   105   // Perform actual processing.

   106   list($percentage, $message) = _batch_process();

   107 

   108   drupal_json(array('status' => TRUE, 'percentage' => $percentage, 'message' => $message));

   109 }

   110 

   111 /**

   112  * Batch processing page without JavaScript support.

   113  */

   114 function _batch_progress_page_nojs() {

   115   $batch =& batch_get();

   116   $current_set = _batch_current_set();

   117 

   118   drupal_set_title($current_set['title']);

   119 

   120   $new_op = 'do_nojs';

   121 

   122   if (!isset($batch['running'])) {

   123     // This is the first page so we return some output immediately.

   124     $percentage = 0;

   125     $message = $current_set['init_message'];

   126     $batch['running'] = TRUE;

   127   }

   128   else {

   129     // This is one of the later requests: do some processing first.

   130 

   131     // Error handling: if PHP dies due to a fatal error (e.g. non-existant

   132     // function), it will output whatever is in the output buffer,

   133     // followed by the error message.

   134     ob_start();

   135     $fallback = $current_set['error_message'] .'<br/>'. $batch['error_message'];

   136     $fallback = theme('maintenance_page', $fallback, FALSE, FALSE);

   137 

   138     // We strip the end of the page using a marker in the template, so any

   139     // additional HTML output by PHP shows up inside the page rather than

   140     // below it. While this causes invalid HTML, the same would be true if

   141     // we didn't, as content is not allowed to appear after </html> anyway.

   142     list($fallback) = explode('<!--partial-->', $fallback);

   143     print $fallback;

   144 

   145     // Perform actual processing.

   146     list($percentage, $message) = _batch_process($batch);

   147     if ($percentage == 100) {

   148       $new_op = 'finished';

   149     }

   150 

   151     // PHP did not die : remove the fallback output.

   152     ob_end_clean();

   153   }

   154 

   155   $url = url($batch['url'], array('query' => array('id' => $batch['id'], 'op' => $new_op)));

   156   drupal_set_html_head('<meta http-equiv="Refresh" content="0; URL='. $url .'">');

   157   $output = theme('progress_bar', $percentage, $message);

   158   return $output;

   159 }

   160 

   161 /**

   162  * Advance batch processing for 1 second (or process the whole batch if it

   163  * was not set for progressive execution - e.g forms submitted by drupal_execute).

   164  */

   165 function _batch_process() {

   166   $batch =& batch_get();

   167   $current_set =& _batch_current_set();

   168   $set_changed = TRUE;

   169 

   170   if ($batch['progressive']) {

   171     timer_start('batch_processing');

   172   }

   173 

   174   while (!$current_set['success']) {

   175     // If this is the first time we iterate this batch set in the current

   176     // request, we check if it requires an additional file for functions

   177     // definitions.

   178     if ($set_changed && isset($current_set['file']) && is_file($current_set['file'])) {

   179       include_once($current_set['file']);

   180     }

   181 

   182     $finished = 1;

   183     $task_message = '';

   184     if ((list($function, $args) = reset($current_set['operations'])) && function_exists($function)) {

   185       // Build the 'context' array, execute the function call,

   186       // and retrieve the user message.

   187       $batch_context = array('sandbox' => &$current_set['sandbox'], 'results' => &$current_set['results'], 'finished' => &$finished, 'message' => &$task_message);

   188       // Process the current operation.

   189       call_user_func_array($function, array_merge($args, array(&$batch_context)));

   190     }

   191 

   192     if ($finished == 1) {

   193       // Make sure this step isn't counted double when computing $current.

   194       $finished = 0;

   195       // Remove the operation and clear the sandbox.

   196       array_shift($current_set['operations']);

   197       $current_set['sandbox'] = array();

   198     }

   199 

   200     // If the batch set is completed, browse through the remaining sets,

   201     // executing 'control sets' (stored form submit handlers) along the way -

   202     // this might in turn insert new batch sets.

   203     // Stop when we find a set that actually has operations.

   204     $set_changed = FALSE;

   205     $old_set = $current_set;

   206     while (empty($current_set['operations']) && ($current_set['success'] = TRUE) && _batch_next_set()) {

   207       $current_set =& _batch_current_set();

   208       $set_changed = TRUE;

   209     }

   210     // At this point, either $current_set is a 'real' batch set (has operations),

   211     // or all sets have been completed.

   212 

   213     // If we're in progressive mode, stop after 1 second.

   214     if ($batch['progressive'] && timer_read('batch_processing') > 1000) {

   215       break;

   216     }

   217   }

   218 

   219   if ($batch['progressive']) {

   220     // Gather progress information.

   221 

   222     // Reporting 100% progress will cause the whole batch to be considered

   223     // processed. If processing was paused right after moving to a new set,

   224     // we have to use the info from the new (unprocessed) one.

   225     if ($set_changed && isset($current_set['operations'])) {

   226       // Processing will continue with a fresh batch set.

   227       $remaining = count($current_set['operations']);

   228       $total = $current_set['total'];

   229       $progress_message = $current_set['init_message'];

   230       $task_message = '';

   231     }

   232     else {

   233       $remaining = count($old_set['operations']);

   234       $total = $old_set['total'];

   235       $progress_message = $old_set['progress_message'];

   236     }

   237 

   238     $current    = $total - $remaining + $finished;

   239     $percentage = $total ? floor($current / $total * 100) : 100;

   240     $values = array(

   241       '@remaining'  => $remaining,

   242       '@total'      => $total,

   243       '@current'    => floor($current),

   244       '@percentage' => $percentage,

   245       );

   246     $message = strtr($progress_message, $values) .'<br/>';

   247     $message .= $task_message ? $task_message : '&nbsp';

   248 

   249     return array($percentage, $message);

   250   }

   251   else {

   252     // If we're not in progressive mode, the whole batch has been processed by now.

   253     return _batch_finished();

   254   }

   255 

   256 }

   257 

   258 /**

   259  * Retrieve the batch set being currently processed.

   260  */

   261 function &_batch_current_set() {

   262   $batch =& batch_get();

   263   return $batch['sets'][$batch['current_set']];

   264 }

   265 

   266 /**

   267  * Move execution to the next batch set if any, executing the stored

   268  * form _submit handlers along the way (thus possibly inserting

   269  * additional batch sets).

   270  */

   271 function _batch_next_set() {

   272   $batch =& batch_get();

   273   if (isset($batch['sets'][$batch['current_set'] + 1])) {

   274     $batch['current_set']++;

   275     $current_set =& _batch_current_set();

   276     if (isset($current_set['form_submit']) && ($function = $current_set['form_submit']) && function_exists($function)) {

   277       // We use our stored copies of $form and $form_state, to account for

   278       // possible alteration by the submit handlers.

   279       $function($batch['form'], $batch['form_state']);

   280     }

   281     return TRUE;

   282   }

   283 }

   284 

   285 /**

   286  * End the batch processing:

   287  * Call the 'finished' callbacks to allow custom handling of results,

   288  * and resolve page redirection.

   289  */

   290 function _batch_finished() {

   291   $batch =& batch_get();

   292 

   293   // Execute the 'finished' callbacks for each batch set.

   294   foreach ($batch['sets'] as $key => $batch_set) {

   295     if (isset($batch_set['finished'])) {

   296       // Check if the set requires an additional file for functions definitions.

   297       if (isset($batch_set['file']) && is_file($batch_set['file'])) {

   298         include_once($batch_set['file']);

   299       }

   300       if (function_exists($batch_set['finished'])) {

   301         $batch_set['finished']($batch_set['success'], $batch_set['results'], $batch_set['operations']);

   302       }

   303     }

   304   }

   305 

   306   // Cleanup the batch table and unset the global $batch variable.

   307   if ($batch['progressive']) {

   308     db_query("DELETE FROM {batch} WHERE bid = %d", $batch['id']);

   309   }

   310   $_batch = $batch;

   311   $batch = NULL;

   312 

   313   // Redirect if needed.

   314   if ($_batch['progressive']) {

   315     // Put back the 'destination' that was saved in batch_process().

   316     if (isset($_batch['destination'])) {

   317       $_REQUEST['destination'] = $_batch['destination'];

   318     }

   319 

   320     // Use $_batch['form_state']['redirect'], or $_batch['redirect'],

   321     // or $_batch['source_page'].

   322     if (isset($_batch['form_state']['redirect'])) {

   323       $redirect = $_batch['form_state']['redirect'];

   324     }

   325     elseif (isset($_batch['redirect'])) {

   326       $redirect = $_batch['redirect'];

   327     }

   328     else {

   329       $redirect = $_batch['source_page'];

   330     }

   331 

   332     // Let drupal_redirect_form handle redirection logic.

   333     $form = isset($batch['form']) ? $batch['form'] : array();

   334     if (empty($_batch['form_state']['rebuild']) && empty($_batch['form_state']['storage'])) {

   335       drupal_redirect_form($form, $redirect);

   336     }

   337 

   338     // We get here if $form['#redirect'] was FALSE, or if the form is a

   339     // multi-step form. We save the final $form_state value to be retrieved

   340     // by drupal_get_form, and we redirect to the originating page.

   341     $_SESSION['batch_form_state'] = $_batch['form_state'];

   342     drupal_goto($_batch['source_page']);

   343   }

   344 }

   345 

   346 /**

   347  * Shutdown function: store the batch data for next request,

   348  * or clear the table if the batch is finished.

   349  */

   350 function _batch_shutdown() {

   351   if ($batch = batch_get()) {

   352     db_query("UPDATE {batch} SET batch = '%s' WHERE bid = %d", serialize($batch), $batch['id']);

   353   }

   354 }