Outputs a batch processing page with JavaScript support.
This initializes the batch and error messages. Note that in JavaScript-based processing, the batch processing page is displayed only once and updated via AHAH requests, so only the first batch set gets to define the page title. Titles specified by subsequent batch sets are not displayed.
function _batch_progress_page_js() {
$batch = batch_get();
$current_set = _batch_current_set();
drupal_set_title($current_set['title'], PASS_THROUGH);
// Merge required query parameters for batch processing into those provided by
// batch_set() or hook_batch_alter().
$batch['url_options']['query']['id'] = $batch['id'];
$js_setting = array(
'batch' => array(
'errorMessage' => $current_set['error_message'] . '<br />' . $batch['error_message'],
'initMessage' => $current_set['init_message'],
'uri' => url($batch['url'], $batch['url_options']),
),
);
drupal_add_js($js_setting, 'setting');
drupal_add_library('system', 'drupal.batch');
return '<div id="progress"></div>';
}