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   1  <?php
   2  // $Id: batch.inc,v 1.14.2.1 2010/08/06 11:52:19 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      drupal_maintenance_theme();
 137      $fallback = theme('maintenance_page', $fallback, FALSE, FALSE);
 138  
 139      // We strip the end of the page using a marker in the template, so any
 140      // additional HTML output by PHP shows up inside the page rather than
 141      // below it. While this causes invalid HTML, the same would be true if
 142      // we didn't, as content is not allowed to appear after </html> anyway.
 143      list($fallback) = explode('<!--partial-->', $fallback);
 144      print $fallback;
 145  
 146      // Perform actual processing.
 147      list($percentage, $message) = _batch_process($batch);
 148      if ($percentage == 100) {
 149        $new_op = 'finished';
 150      }
 151  
 152      // PHP did not die : remove the fallback output.
 153      ob_end_clean();
 154    }
 155  
 156    $url = url($batch['url'], array('query' => array('id' => $batch['id'], 'op' => $new_op)));
 157    drupal_set_html_head('<meta http-equiv="Refresh" content="0; URL='. $url .'">');
 158    $output = theme('progress_bar', $percentage, $message);
 159    return $output;
 160  }
 161  
 162  /**
 163   * Advance batch processing for 1 second (or process the whole batch if it
 164   * was not set for progressive execution - e.g forms submitted by drupal_execute).
 165   */
 166  function _batch_process() {
 167    $batch =& batch_get();
 168    $current_set =& _batch_current_set();
 169    $set_changed = TRUE;
 170  
 171    if ($batch['progressive']) {
 172      timer_start('batch_processing');
 173    }
 174  
 175    while (!$current_set['success']) {
 176      // If this is the first time we iterate this batch set in the current
 177      // request, we check if it requires an additional file for functions
 178      // definitions.
 179      if ($set_changed && isset($current_set['file']) && is_file($current_set['file'])) {
 180        include_once($current_set['file']);
 181      }
 182  
 183      $finished = 1;
 184      $task_message = '';
 185      if ((list($function, $args) = reset($current_set['operations'])) && function_exists($function)) {
 186        // Build the 'context' array, execute the function call,
 187        // and retrieve the user message.
 188        $batch_context = array('sandbox' => &$current_set['sandbox'], 'results' => &$current_set['results'], 'finished' => &$finished, 'message' => &$task_message);
 189        // Process the current operation.
 190        call_user_func_array($function, array_merge($args, array(&$batch_context)));
 191      }
 192  
 193      if ($finished == 1) {
 194        // Make sure this step isn't counted double when computing $current.
 195        $finished = 0;
 196        // Remove the operation and clear the sandbox.
 197        array_shift($current_set['operations']);
 198        $current_set['sandbox'] = array();
 199      }
 200  
 201      // If the batch set is completed, browse through the remaining sets,
 202      // executing 'control sets' (stored form submit handlers) along the way -
 203      // this might in turn insert new batch sets.
 204      // Stop when we find a set that actually has operations.
 205      $set_changed = FALSE;
 206      $old_set = $current_set;
 207      while (empty($current_set['operations']) && ($current_set['success'] = TRUE) && _batch_next_set()) {
 208        $current_set =& _batch_current_set();
 209        $set_changed = TRUE;
 210      }
 211      // At this point, either $current_set is a 'real' batch set (has operations),
 212      // or all sets have been completed.
 213  
 214      // If we're in progressive mode, stop after 1 second.
 215      if ($batch['progressive'] && timer_read('batch_processing') > 1000) {
 216        break;
 217      }
 218    }
 219  
 220    if ($batch['progressive']) {
 221      // Gather progress information.
 222  
 223      // Reporting 100% progress will cause the whole batch to be considered
 224      // processed. If processing was paused right after moving to a new set,
 225      // we have to use the info from the new (unprocessed) one.
 226      if ($set_changed && isset($current_set['operations'])) {
 227        // Processing will continue with a fresh batch set.
 228        $remaining = count($current_set['operations']);
 229        $total = $current_set['total'];
 230        $progress_message = $current_set['init_message'];
 231        $task_message = '';
 232      }
 233      else {
 234        $remaining = count($old_set['operations']);
 235        $total = $old_set['total'];
 236        $progress_message = $old_set['progress_message'];
 237      }
 238  
 239      $current    = $total - $remaining + $finished;
 240      $percentage = $total ? floor($current / $total * 100) : 100;
 241      $values = array(
 242        '@remaining'  => $remaining,
 243        '@total'      => $total,
 244        '@current'    => floor($current),
 245        '@percentage' => $percentage,
 246        );
 247      $message = strtr($progress_message, $values) .'<br/>';
 248      $message .= $task_message ? $task_message : '&nbsp';
 249  
 250      return array($percentage, $message);
 251    }
 252    else {
 253      // If we're not in progressive mode, the whole batch has been processed by now.
 254      return _batch_finished();
 255    }
 256  
 257  }
 258  
 259  /**
 260   * Retrieve the batch set being currently processed.
 261   */
 262  function &_batch_current_set() {
 263    $batch =& batch_get();
 264    return $batch['sets'][$batch['current_set']];
 265  }
 266  
 267  /**
 268   * Move execution to the next batch set if any, executing the stored
 269   * form _submit handlers along the way (thus possibly inserting
 270   * additional batch sets).
 271   */
 272  function _batch_next_set() {
 273    $batch =& batch_get();
 274    if (isset($batch['sets'][$batch['current_set'] + 1])) {
 275      $batch['current_set']++;
 276      $current_set =& _batch_current_set();
 277      if (isset($current_set['form_submit']) && ($function = $current_set['form_submit']) && function_exists($function)) {
 278        // We use our stored copies of $form and $form_state, to account for
 279        // possible alteration by the submit handlers.
 280        $function($batch['form'], $batch['form_state']);
 281      }
 282      return TRUE;
 283    }
 284  }
 285  
 286  /**
 287   * End the batch processing:
 288   * Call the 'finished' callbacks to allow custom handling of results,
 289   * and resolve page redirection.
 290   */
 291  function _batch_finished() {
 292    $batch =& batch_get();
 293  
 294    // Execute the 'finished' callbacks for each batch set.
 295    foreach ($batch['sets'] as $key => $batch_set) {
 296      if (isset($batch_set['finished'])) {
 297        // Check if the set requires an additional file for functions definitions.
 298        if (isset($batch_set['file']) && is_file($batch_set['file'])) {
 299          include_once($batch_set['file']);
 300        }
 301        if (function_exists($batch_set['finished'])) {
 302          $batch_set['finished']($batch_set['success'], $batch_set['results'], $batch_set['operations']);
 303        }
 304      }
 305    }
 306  
 307    // Cleanup the batch table and unset the global $batch variable.
 308    if ($batch['progressive']) {
 309      db_query("DELETE FROM {batch} WHERE bid = %d", $batch['id']);
 310    }
 311    $_batch = $batch;
 312    $batch = NULL;
 313  
 314    // Redirect if needed.
 315    if ($_batch['progressive']) {
 316      // Put back the 'destination' that was saved in batch_process().
 317      if (isset($_batch['destination'])) {
 318        $_REQUEST['destination'] = $_batch['destination'];
 319      }
 320  
 321      // Use $_batch['form_state']['redirect'], or $_batch['redirect'],
 322      // or $_batch['source_page'].
 323      if (isset($_batch['form_state']['redirect'])) {
 324        $redirect = $_batch['form_state']['redirect'];
 325      }
 326      elseif (isset($_batch['redirect'])) {
 327        $redirect = $_batch['redirect'];
 328      }
 329      else {
 330        $redirect = $_batch['source_page'];
 331      }
 332  
 333      // Let drupal_redirect_form handle redirection logic.
 334      $form = isset($batch['form']) ? $batch['form'] : array();
 335      if (empty($_batch['form_state']['rebuild']) && empty($_batch['form_state']['storage'])) {
 336        drupal_redirect_form($form, $redirect);
 337      }
 338  
 339      // We get here if $form['#redirect'] was FALSE, or if the form is a
 340      // multi-step form. We save the final $form_state value to be retrieved
 341      // by drupal_get_form, and we redirect to the originating page.
 342      $_SESSION['batch_form_state'] = $_batch['form_state'];
 343      drupal_goto($_batch['source_page']);
 344    }
 345  }
 346  
 347  /**
 348   * Shutdown function: store the batch data for next request,
 349   * or clear the table if the batch is finished.
 350   */
 351  function _batch_shutdown() {
 352    if ($batch = batch_get()) {
 353      db_query("UPDATE {batch} SET batch = '%s' WHERE bid = %d", serialize($batch), $batch['id']);
 354    }
 355  }