'Queue Example: Insert and remove',
'page callback' => 'drupal_get_form',
'page arguments' => array('queue_example_add_remove_form'),
'access callback' => TRUE,
);
return $items;
}
/**
* Provides an interface to add items to the queue, to retrieve (claim)
* an item from the head of the queue, and to claim and delete. Also
* allows the user to run cron manually, so that claimed items can be
* released.
*/
function queue_example_add_remove_form($form, &$form_state) {
// Simple counter that makes it possible to put auto-incrementing default
// string into the string to insert.
if (empty($form_state['storage']['insert_counter'])) {
$form_state['storage']['insert_counter'] = 1;
}
$queue_name = !empty($form_state['values']['queue_name']) ? $form_state['values']['queue_name'] : 'queue_example_first_queue';
$items = queue_example_retrieve_queue($queue_name);
// Add CSS to make the form a bit denser.
$form['#attached']['css'] = array(drupal_get_path('module', 'queue_example') . '/queue_example.css');
$form['help'] = array(
'#type' => 'markup',
'#markup' => '' . t('This page is an interface on the Drupal queue API. You can add new items to the queue, "claim" one (retrieve the next item and keep a lock on it), and delete one (remove it from the queue). Note that claims are not expired until cron runs, so there is a special button to run cron to perform any necessary expirations.') . '
',
);
$form['queue_name'] = array(
'#type' => 'select',
'#title' => t('Choose queue'),
'#options' => drupal_map_assoc(array('queue_example_first_queue', 'queue_example_second_queue')),
);
$form['insert_fieldset'] = array(
'#type' => 'fieldset',
'#title' => t('Insert into queue'),
);
$form['insert_fieldset']['string_to_add'] = array(
'#type' => 'textfield',
'#size' => 10,
'#default_value' => t('item @counter', array('@counter' => $form_state['storage']['insert_counter'])),
);
$form['insert_fieldset']['add_item'] = array(
'#type' => 'submit',
'#value' => t('Insert into queue'),
'#submit' => array('queue_example_add_remove_form_insert'),
);
$form['claim_fieldset'] = array(
'#type' => 'fieldset',
'#title' => t('Claim from queue'),
'#collapsible' => TRUE,
);
$form['claim_fieldset']['claim_time'] = array(
'#type' => 'radios',
'#title' => t('Claim time, in seconds'),
'#options' => array(0 => t('none'), 5 => t('5 seconds'), 60 => t('60 seconds')),
'#description' => t('This time is only valid if cron runs during this time period. You can run cron manually below.'),
'#default_value' => !empty($form_state['values']['claim_time']) ? $form_state['values']['claim_time'] : 5,
);
$form['claim_fieldset']['claim_item'] = array(
'#type' => 'submit',
'#value' => t('Claim the next item from the queue'),
'#submit' => array('queue_example_add_remove_form_claim'),
);
$form['claim_fieldset']['claim_and_delete_item'] = array(
'#type' => 'submit',
'#value' => t('Claim the next item and delete it'),
'#submit' => array('queue_example_add_remove_form_delete'),
);
$form['run_cron'] = array(
'#type' => 'submit',
'#value' => t('Run cron manually (to expire claimed items)'),
'#submit' => array('queue_example_add_remove_form_run_cron'),
);
$form['delete_queue'] = array(
'#type' => 'submit',
'#value' => t('Delete the queue and items in it'),
'#submit' => array('queue_example_add_remove_form_clear_queue'),
);
$form['status_fieldset'] = array(
'#type' => 'fieldset',
'#title' => t('Queue status'),
'#collapsible' => TRUE,
);
$form['status_fieldset']['status'] = array(
'#type' => 'markup',
'#markup' => t('Queue status for queue @name:', array('@name' => $queue_name)) . '
' . theme('queue_items', array('items' => $items)),
);
return $form;
}
/**
* Submit function for the insert-into-queue button.
*/
function queue_example_add_remove_form_insert($form, &$form_state) {
// Get a queue (of the default type) called 'queue_example_queue'.
// If the default queue class is SystemQueue this creates a queue that stores
// its items in the database.
$queue = DrupalQueue::get($form_state['values']['queue_name']);
$queue->createQueue(); // There is no harm in trying to recreate existing.
// Queue the string.
$queue->createItem($form_state['values']['string_to_add']);
$count = $queue->numberOfItems();
drupal_set_message(t('Queued your string (@string_to_add). There are now @count items in the queue.', array('@count' => $count, '@string_to_add' => $form_state['values']['string_to_add'])));
$form_state['rebuild'] = TRUE; // Allows us to keep information in $form_state.
// Unsetting the string_to_add allows us to set the incremented default value
// for the user so they don't have to type anything.
unset($form_state['input']['string_to_add']);
$form_state['storage']['insert_counter']++;
}
/**
* Submit function for the "claim" button. Claims (retrieves) an item from
* the queue and reports the results.
*/
function queue_example_add_remove_form_claim($form, &$form_state) {
$queue = DrupalQueue::get($form_state['values']['queue_name']);
$queue->createQueue(); // There is no harm in trying to recreate existing.
$item = $queue->claimItem($form_state['values']['claim_time']);
$count = $queue->numberOfItems();
if (!empty($item)) {
drupal_set_message(t('Claimed item id=@item_id string=@string for @seconds seconds. There are @count items in the queue.', array('@count' => $count, '@item_id' => $item->item_id, '@string' => $item->data, '@seconds' => $form_state['values']['claim_time'])));
}
else {
drupal_set_message(t('There were no items in the queue available to claim. There are @count items in the queue.', array('@count' => $count)));
}
$form_state['rebuild'] = TRUE;
}
/**
* Submit function for "Claim and delete" button.
*/
function queue_example_add_remove_form_delete($form, &$form_state) {
$queue = DrupalQueue::get($form_state['values']['queue_name']);
$queue->createQueue(); // There is no harm in trying to recreate existing.
$count = $queue->numberOfItems();
$item = $queue->claimItem(60);
if (!empty($item)) {
drupal_set_message(t('Claimed and deleted item id=@item_id string=@string for @seconds seconds. There are @count items in the queue.', array('@count' => $count, '@item_id' => $item->item_id, '@string' => $item->data, '@seconds' => $form_state['values']['claim_time'])));
$queue->deleteItem($item);
$count = $queue->numberOfItems();
drupal_set_message(t('There are now @count items in the queue.', array('@count' => $count)));
}
else {
$count = $queue->numberOfItems();
drupal_set_message(t('There were no items in the queue available to claim/delete. There are currently @count items in the queue.', array('@count' => $count)));
}
$form_state['rebuild'] = TRUE;
}
/**
* Submit function for "run cron" button.
*
* Runs cron (to release expired claims) and reports the results.
*/
function queue_example_add_remove_form_run_cron($form, &$form_state) {
drupal_cron_run();
$queue = DrupalQueue::get($form_state['values']['queue_name']);
$queue->createQueue(); // There is no harm in trying to recreate existing.
$count = $queue->numberOfItems();
drupal_set_message(t('Ran cron. If claimed items expired, they should be expired now. There are now @count items in the queue', array('@count' => $count)));
$form_state['rebuild'] = TRUE;
}
/**
* Submit handler for clearing/deleting the queue.
*/
function queue_example_add_remove_form_clear_queue($form, &$form_state) {
$queue = DrupalQueue::get($form_state['values']['queue_name']);
$queue->deleteQueue();
drupal_set_message(t('Deleted the @queue_name queue and all items in it', array('@queue_name' => $form_state['values']['queue_name'])));
}
/**
* Retrieve the queue from the database for display purposes only.
*
* It is not recommended to access the database directly, and this is only here
* so that the user interface can give a good idea of what's going on in the
* queue.
*
* @param $queue_name
* The name of the queue from which to fetch items.
*/
function queue_example_retrieve_queue($queue_name) {
$items = array();
$result = db_query("SELECT item_id, data, expire, created FROM {queue} WHERE name = :name ORDER BY item_id",
array(':name' => $queue_name),
array('fetch' => PDO::FETCH_ASSOC));
foreach ($result as $item) {
$items[] = $item;
}
return $items;
}
/**
* Theme the queue display.
*
* Again, this is not part of the demonstration of the queue API, but is here
* just to make the user interface more understandable.
*
* @param $variables
*/
function theme_queue_items($variables) {
$items = $variables['items'];
$rows = array();
foreach ($items as &$item) {
if ($item['expire'] > 0) {
$item['expire'] = t("Claimed: expires %expire", array('%expire' => date('r', $item['expire'])));
}
else {
$item['expire'] = t('Unclaimed');
}
$item['created'] = date('r', $item['created']);
$item['content'] = check_plain(unserialize($item['data']));
unset($item['data']);
$rows[] = $item;
}
if (!empty($rows)) {
$header = array(t('Item ID'), t('Claimed/Expiration'), t('Created'), t('Content/Data'));
$output = theme('table', array('header' => $header, 'rows' => $rows));
return $output;
}
else {
return t('There are no items in the queue.');
}
}
/**
* Implements hook_theme().
*/
function queue_example_theme() {
return array(
'queue_items' => array(
'variables' => array('items' => NULL),
),
);
}