t('All comments'),
COMMENT_NOTIFY_COMMENT => t('Replies to my comment')
);
$available_options = array();
$options = variable_get('comment_notify_available_alerts', drupal_map_assoc(array(COMMENT_NOTIFY_NODE, COMMENT_NOTIFY_COMMENT)));
foreach ($options as $key => $available) {
if ($key == $available) {
$available_options[$available] = $total_options[$available];
}
}
return $available_options;
}
/**
* Insert our checkbox, add a submit button, and populate fields.
*/
function comment_notify_form_alter(&$form, &$form_state, $form_id) {
global $user;
// Only alter the form if it's a comment form and the user has the permission to subscribe.
if ($form_id == 'comment_form' && (user_access('subscribe to comments') || user_access('administer comments'))) {
// Only add the checkbox if this is an enabled content type
$node = node_load($form['nid']['#value'] ? $form['nid']['#value'] : $form['nid']['#default_value']);
$enabled_types = variable_get('comment_notify_node_types', drupal_map_assoc(array($node->type)));
if (empty($enabled_types[$node->type])) {
return;
}
$available_options = _comment_notify_options();
drupal_add_css(drupal_get_path('module', 'comment_notify') .'/comment_notify.css');
drupal_add_js(drupal_get_path('module', 'comment_notify') .'/comment_notify.js');
// Add the checkbox for anonymous users and set the default based on admin settings.
if ($user->uid == 0) {
// If anonymous user's can't enter their e-mail don't tempt them with the checkbox.
if (empty($form['mail'])) {
return;
}
$preference = variable_get('comment_notify_default_anon_mailalert', COMMENT_NOTIFY_DISABLED);
}
else {
$user_preference = db_result(db_query("SELECT comment_notify FROM {comment_notify_user_settings} WHERE uid = %d", $user->uid));
$preference = strlen($user_preference) ? $user_preference : variable_get('comment_notify_default_registered_mailalert', COMMENT_NOTIFY_DISABLED);
}
// If you want to hide this on your site see http://drupal.org/node/322482
$form['notify_settings'] = array(
'#prefix' => '
',
'#suffix' => '
',
);
$form['notify_settings']['notify'] = array(
'#type' => 'checkbox',
'#title' => t('Notify me when new comments are posted'),
'#default_value' => $preference,
);
if (count($available_options) > 1) {
$form['notify_settings']['notify_type'] = array(
'#type' => 'radios',
'#options' => $available_options,
'#default_value' => $preference,
);
}
else {
$form['notify_settings']['notify_type'] = array(
'#type' => 'hidden',
'#value' => key($available_options),
);
}
$form['notify_settings']['notify_type']['#default_value'] = $preference;
// If this is an existing comment we set the default value based on their selection last time.
if ($form['cid']['#value'] != '') {
$notify = db_result(db_query("SELECT notify FROM {comment_notify} WHERE cid = %d", $form['cid']['#value']));
$form['notify_settings']['notify']['#default_value'] = $notify;
if (count($available_options) > 1) {
$form['notify_settings']['notify_type']['#default_value'] = $notify;
}
else {
$form['notify_settings']['notify_type']['#default_value'] = key($available_options);
}
}
}
}
/**
* Implementation of hook_perm().
*/
function comment_notify_perm() {
return array('administer comment notify', 'subscribe to comments');
}
/**
* Implementation of hook_menu().
*/
function comment_notify_menu() {
$items['admin/settings/comment_notify'] = array(
'title' => 'Comment notify',
'description' => 'Configure settings for e-mails about new comments.',
'page callback' => 'drupal_get_form',
'page arguments' => array('comment_notify_settings'),
'access arguments' => array('administer comment notify'),
'type' => MENU_NORMAL_ITEM,
);
$items['admin/settings/comment_notify/settings'] = array(
'title' => 'Settings',
'description' => 'Configure settings for e-mails about new comments.',
'page callback' => 'drupal_get_form',
'page arguments' => array('comment_notify_settings'),
'access arguments' => array('administer comment notify'),
'type' => MENU_DEFAULT_LOCAL_TASK,
);
$items['admin/settings/comment_notify/unsubscribe'] = array(
'title' => 'Unsubscribe',
'description' => 'Unsubscribe an email from all notifications.',
'weight' => 2,
'page callback' => 'drupal_get_form',
'page arguments' => array('comment_notify_unsubscribe'),
'access arguments' => array('administer comment notify'),
'type' => MENU_LOCAL_TASK,
);
$items['comment_notify/disable/%'] = array(
'title' => 'Disable comment notification',
'page callback' => 'comment_notify_disable_page',
'page arguments' => array(2),
'access arguments' => array('access content'),
'type' => MENU_CALLBACK
);
return $items;
}
/**
* Page callback to allow users to unsubscribe simply by visiting the page.
*/
function comment_notify_disable_page($hash) {
db_query("UPDATE {comment_notify} SET notify = 0 WHERE notify_hash = '%s'", $hash);
drupal_set_message(t('Your comment follow-up notification for this post was disabled. Thanks.'));
return ' ';
}
/**
* Implementation of hook_comment().
*/
function comment_notify_comment($comment, $op) {
global $user;
// In theory, the update or insert operations are duplicates with publish which
// would lead to duplicate messages. _comment_notify_mailalert() protects against that.
switch ($op) {
case 'validate':
// We assume that if they are non-anonymous then they have a valid mail.
// For anonymous users, though, we verify that they entered a mail and let comment.module validate it is real.
if (!$user->uid && $comment['notify'] && empty($comment['mail'])) {
form_set_error('mail', t('If you want to subscribe to comments you must supply a valid e-mail address.'));
}
break;
case 'publish':
// And send notifications - the real purpose of the module.
_comment_notify_mailalert($comment);
break;
case 'update':
// In case they have changed their status, save it in the database.
$sql = 'UPDATE {comment_notify} SET notify = %d WHERE cid = %d';
if ($comment['notify']) {
db_query($sql, $comment['notify_type'], $comment['cid']);
}
else {
db_query($sql, 0, $comment['cid']);
}
// And send notifications - the real purpose of the module.
if ($comment['status'] == COMMENT_PUBLISHED) {
_comment_notify_mailalert($comment);
}
break;
case 'insert':
// For new comments, we first build up a string to be used as the identifier for the alert
$mail = empty($comment['mail']) ? $user->mail : $comment['mail'];
$notify_hash = drupal_get_token($mail . $comment['cid']);
if ($comment['notify']) {
$notify = $comment['notify_type'];
// If they don't have a preference, save one.
$current = db_result(db_query("SELECT count(1) from {comment_notify_user_settings} WHERE uid = %d", $user->uid));
if ($current == 0 && $user->uid) {
db_query("INSERT INTO {comment_notify_user_settings} (uid, comment_notify) VALUES (%d, %d)", $user->uid, $comment['notify_type']);
}
}
else {
$notify = $comment['notify'];
}
// And then save the data.
db_query("INSERT INTO {comment_notify} (cid, notify, notify_hash) values (%d, %d, '%s')", $comment['cid'], $notify, $notify_hash);
// And send notifications - the real purpose of the module.
if ($comment['status'] == COMMENT_PUBLISHED) {
_comment_notify_mailalert($comment);
}
break;
case 'delete':
db_query("DELETE FROM {comment_notify} WHERE cid = %d", $comment->cid);
break;
}
}
/**
* Implementation of hook_user().
*/
function comment_notify_user($type, &$edit, &$user, $category = NULL) {
switch ($type) {
case 'form':
if ($category == 'account' && user_access('subscribe to comments', $user)) {
$form = array();
$form['comment_notify_settings'] = array(
'#type' => 'fieldset',
'#title' => t('Comment follow-up notification settings'),
'#weight' => 4,
'#collapsible' => TRUE
);
// Only show the node followup UI if the user has permission to create nodes.
$nodes = FALSE;
foreach (node_get_types() as $type) {
if (user_access('create '. $type->type .' content')) {
$nodes = TRUE;
break;
}
}
if (user_access('administer nodes') || $nodes) {
$form['comment_notify_settings']['node_notify_mailalert'] = array(
'#type' => 'checkbox',
'#title' => t('Receive node follow-up notification e-mails'),
'#default_value' => isset($edit['node_notify_mailalert']) ? $edit['node_notify_mailalert'] : variable_get('node_notify_default_mailalert', FALSE),
'#description' => t('Check this box to receive an e-mail notification for follow-ups on your nodes (pages, forum topics, etc). You can not disable notifications for individual threads.')
);
}
else {
$form['comment_notify_settings']['node_notify_mailalert'] = array(
'#type' => 'hidden',
'#value' => COMMENT_NOTIFY_DISABLED,
);
}
$available_options[COMMENT_NOTIFY_DISABLED] = t('No notifications');
$available_options += _comment_notify_options();
$form['comment_notify_settings']['comment_notify_mailalert'] = array(
'#type' => 'select',
'#title' => t('Receive comment follow-up notification e-mails'),
'#default_value' => isset($edit['comment_notify_mailalert']) ? $edit['comment_notify_mailalert'] : variable_get('comment_notify_default_registered_mailalert', COMMENT_NOTIFY_DISABLED),
'#options' => $available_options,
'#description' => t("Check this box to receive e-mail notification for follow-up comments to comments you posted. You can later disable this on a post-by-post basis... so if you leave this to YES, you can still disable follow-up notifications for comments you don't want follow-up mails anymore - i.e. for very popular posts.")
);
return $form;
}
break;
case 'submit':
// Save the values of node_notify_mailalert and comment_notify_mailalert
// to {comment_notify_user_settings}.
db_query('UPDATE {comment_notify_user_settings} SET node_notify = %d, comment_notify = %d WHERE uid = %d', $edit['node_notify_mailalert'], $edit['comment_notify_mailalert'], $user->uid);
if (!db_affected_rows()) {
db_query('INSERT INTO {comment_notify_user_settings} (uid, node_notify, comment_notify) VALUES (%d, %d, %d)', $user->uid, $edit['node_notify_mailalert'], $edit['comment_notify_mailalert']);
}
// Unset them from $user so they don't also get saved into {users}.data.
unset($edit['node_notify_mailalert']);
unset($edit['comment_notify_mailalert']);
break;
case 'load':
$user_settings = db_fetch_array(db_query('SELECT node_notify AS node_notify_mailalert, comment_notify AS comment_notify_mailalert FROM {comment_notify_user_settings} WHERE uid = %d', $user->uid));
if (!empty($user_settings)) {
foreach ($user_settings as $property => $value) {
$user->$property = $value;
}
}
break;
case 'delete':
db_query('DELETE FROM {comment_notify_user_settings} WHERE uid = %d', $user->uid);
break;
break;
}
}
/**
* Private function to send the notifications.
*
* @param $comment
* The comment array as found in hook_comment $op = publish.
*/
function _comment_notify_mailalert($comment) {
$comment = (object) $comment;
global $language;
global $base_url;
global $user;
$nid = $comment->nid;
$cid = $comment->cid;
// Check to see if a notification has already been sent for this
// comment so that edits to a comment don't trigger an additional
// notification.
if (db_result(db_query('SELECT cid from {comment_notify} WHERE cid = %d AND notified = %d', $cid, 1))) {
return;
}
$initial_language = $language;
if (function_exists('locale')) {
$languages = locale_language_list();
$languages = $languages['name'];
}
$node = node_load($nid);
// Render up the node and comment.
$node_teaser = node_view($node, TRUE, TRUE, FALSE);
$node_body = node_view($node, FALSE, TRUE, FALSE);
$comment_text = check_markup($comment->comment, $comment->format);
// No mails if this is not an enabled content type.
$enabled_types = variable_get('comment_notify_node_types', array($node->type => TRUE));
if (empty($enabled_types[$node->type])) {
return;
}
if (!isset($comment->mail)) {
$comment_account = user_load(array('name' => $comment->name));
$comment_mail = $comment_account->mail;
}
else {
$comment_mail = $comment->mail;
}
$sent_to = array();
// Send to a subscribed author if they are not the current commenter
$author = user_load(array('uid' => $node->uid));
if (!empty($author->node_notify_mailalert) && $author->node_notify_mailalert == 1 && $user->uid != $author->uid && node_access('view', $node, $author)) {
// Get the author's language.
$language = user_preferred_language($author);
$message['subject'] = t('!site :: new comment for your post.', array('!site' => variable_get('site_name', 'drupal')));
$message['body'] = t(
variable_get('node_notify_default_mailtext', AUTHOR_MAILTEXT),
array(
'!commname' => $comment->name,
'!commtext' => drupal_html_to_text($comment_text),
'!commsubj' => $comment->subject,
'!comment_url' => url('node/'. $nid, array('absolute' => TRUE, 'fragment' => 'comment-'. $cid)),
'!node_title' => $node->title,
'!node_teaser' => drupal_html_to_text($node_teaser),
'!mission' => variable_get('site_mission', ''),
'!node_body' => drupal_html_to_text($node_body),
'!name' => $author->name,
'!site' => variable_get('site_name', 'drupal'),
'!uri' => $base_url,
'!uri_brief' => preg_replace('!^https?://!', '', $base_url),
'!date' => format_date(time()),
'!login_uri' => url('user', array('absolute' => TRUE)),
'!edit_uri' => url('user/'. $author->uid .'/edit', array('absolute' => TRUE))
)
);
drupal_mail('comment_notify', 'comment_notify_mail', $author->mail, $language, $message);
$sent_to[] = $author->mail;
}
// For "reply to my comments" notifications, figure out what thread this is.
$thread = db_result(db_query("SELECT thread FROM {comments} WHERE cid = %d", $cid));
//Get the list of commenters to notify
$result = db_query(db_rewrite_sql("SELECT c.cid, c.nid, c.uid, c.name, c.mail AS cmail, u.mail AS umail, u.init AS uinit, c.uid, c.name, cn.notify, cn.notify_hash, c.thread
FROM {comments} c INNER JOIN {comment_notify} cn on c.cid = cn.cid LEFT OUTER JOIN {users} u ON c.uid = u.uid
WHERE c.nid = %d AND cn.notify > 0 AND c.status = 0 AND (u.status = 1 OR u.uid = 0)", 'c', 'cid'), $nid
);
// TODO? the original big query had stuff making sure the mail was populated and contained .+@.+ Perhaps check for that here and set notify = 0 if that is the case for this cid
while ($alert = db_fetch_object($result)) {
$umail = empty($alert->umail) ? $alert->uinit : $alert->umail;
$mail = empty($alert->cmail) ? $umail : $alert->cmail;
$relevant_thread = substr($thread, 0, drupal_strlen($alert->thread) -1);
if ($alert->notify == COMMENT_NOTIFY_COMMENT && strcmp($relevant_thread . '/', $alert->thread) != 0) {
continue;
}
if ($mail != $comment_mail && !in_array($mail, $sent_to) && $alert->uid != $comment->uid) {
$message = array();
if (!empty($alert->uid)) {
$recipient_user = user_load(array('uid' => $alert->uid));
$language = user_preferred_language($recipient_user);
}
else {
$language = language_default();
$recipient_user = drupal_anonymous_user();
}
// Make sure they have access to this node before showing a bunch of node information.
if (!node_access('view', $node, $recipient_user)) {
continue;
}
$message['subject'] = t('!site :: new comment for your post.', array('!site' => variable_get('site_name', 'drupal')));
$message['body'] = t(
variable_get('comment_notify_default_mailtext', DEFAULT_MAILTEXT),
array(
'!commname' => $comment->name,
'!commtext' => drupal_html_to_text($comment_text),
'!commsubj' => $comment->subject,
'!comment_url' => url('node/'. $nid, array('absolute' => TRUE, 'fragment' => 'comment-'. $cid)),
'!node_title' => $node->title,
'!node_teaser' => drupal_html_to_text($node_teaser),
'!mission' => variable_get('site_mission', ''),
'!node_body' => drupal_html_to_text($node_body),
'!name' => $alert->name,
'!site' => variable_get('site_name', 'drupal'),
'!uri' => $base_url,
'!uri_brief' => preg_replace('!^https?://!', '', $base_url),
'!date' => format_date(time()),
'!login_uri' => url('user', array('absolute' => TRUE)),
'!edit_uri' => url('user/'. $alert->uid .'/edit', array('absolute' => TRUE)),
'!link1' => url('comment_notify/disable/'. $alert->notify_hash, array('absolute' => TRUE))
)
);
drupal_mail('comment_notify', 'comment_notify_mail', $mail, $language, $message);
$sent_to[] = $mail;
// Make the mail link to user's /edit, unless it's an anonymous user.
if ($alert->uid != 0) {
$user_mail = l($mail, 'user/'. $alert->uid .'/edit');
}
else {
$user_mail = check_plain($mail);
}
// Add an entry to the watchdog log.
watchdog(
'comment_notify',
'Notified: !user_mail',
array('!user_mail' => $user_mail),
WATCHDOG_NOTICE,
l(t('source comment'), 'node/'. $nid, array(
'fragment' => 'comment-'. $alert->cid,
))
);
// revert to previous (site default) locale
$language = $initial_language;
}
}
// Record that a notification was sent for this comment so that
// notifications aren't sent again if the comment is later edited.
db_query('UPDATE {comment_notify} SET notified = 1 WHERE cid = %d', $cid);
}
/**
* Implementation of hook_mail().
*/
function comment_notify_mail($key, &$message, $params) {
$message['subject'] = $params['subject'];
$message['body'][] = $params['body'];
}
/**
* Callback for an administrative form to unsubscribe users by e-mail address.
*/
function comment_notify_unsubscribe() {
$form['comment_notify_unsubscribe'] = array();
$form['comment_notify_unsubscribe']['email_to_unsubscribe'] = array(
'#type' => 'textfield',
'#title' => t('Email to unsubscribe'),
);
$form['comment_notify_unsubscribe']['submit'] = array(
'#type' => 'submit',
'#value' => t('Unsubscribe this e-mail'),
);
return $form;
}
/**
* Based on admin submit, do the actual unsubscribe from notifications.
*/
function comment_notify_unsubscribe_submit($form, &$form_state) {
$email = trim($form_state['values']['email_to_unsubscribe']);
// If they have a uid, use that, otherwise update comments directly
$result = db_result(db_query_range("SELECT uid FROM {users} WHERE mail = '%s'", $email, 0, 1));
if ($result > 0) {
$comments = db_result(db_query("SELECT COUNT(1) FROM {comments} c INNER JOIN {comment_notify} cn ON c.cid = cn.cid WHERE c.uid = %d AND cn.notify > 0", $result));
db_query("UPDATE {comment_notify} SET notify = 0 WHERE cid IN (SELECT cid FROM {comments} WHERE uid = %d)", $result);
}
else {
$comments = db_result(db_query("SELECT COUNT(1) FROM {comments} c INNER JOIN {comment_notify} cn ON c.cid = cn.cid WHERE c.mail = '%s' AND cn.notify > 0", $email));
db_query("UPDATE {comment_notify} SET notify = 0 WHERE cid IN (SELECT cid FROM {comments} WHERE mail = '%s')", $email);
}
// Update the admin about the state of this comment notification subscription.
if ($comments == 0) {
drupal_set_message(t("There were no active comment notifications for that email."));
}
else {
drupal_set_message(format_plural($comments, "Email unsubscribed from 1 comment notification.",
"Email unsubscribed from @count comment notifications."));
}
}
/*
* Page callback for administrative settings form.
*/
function comment_notify_settings() {
$form['comment_notify_settings'] = array();
// Only perform comment_notify for certain node types (default, all)
$enabled_types = variable_get('comment_notify_node_types', FALSE);
$anonymous_problems = '';
foreach (node_get_types('names') as $type => $name) {
$checkboxes[$type] = check_plain($name);
$default[] = $type;
// If they don't have the ability to leave contact info, then we make a report
if (isset($enabled_types[$type]) && $enabled_types[$type] && variable_get('comment_anonymous_'. $type, COMMENT_ANONYMOUS_MAYNOT_CONTACT) == COMMENT_ANONYMOUS_MAYNOT_CONTACT) {
$account = user_load(array('uid' => 0));
if (user_access('subscribe to comments', $account)) {
$anonymous_problems[] = l(t('@content-type', array('@content-type' => $name)), 'admin/content/node-type/'. $type);
}
}
}
if (!empty($anonymous_problems)) {
drupal_set_message(t('Anonymous commenters have the permission to subscribe to comments but cannot leave their contact infromation on the following content types: !types. You should either disable subscriptions on those types here, revoke the permission for anonymous users, or enable anonymous users to leave their contact information in the comment settings.', array('!types' => implode(', ', $anonymous_problems))), 'status', FALSE);
}
$form['comment_notify_settings']['comment_notify_node_types'] = array(
'#type' => 'checkboxes',
'#title' => t('Content types to enable for comment notification'),
'#default_value' => variable_get('comment_notify_node_types', $default),
'#options' => $checkboxes,
'#description' => t('Comments on content types enabled here will have the option of comment notification.'),
);
$form['comment_notify_settings']['comment_notify_available_alerts'] = array(
'#type' => 'checkboxes',
'#title' => t('Available subscription modes'),
'#return_value' => 1,
'#default_value' => variable_get('comment_notify_available_alerts', array(COMMENT_NOTIFY_NODE, COMMENT_NOTIFY_COMMENT)),
'#description' => t('Choose which notification subscription styles are available for users'),
'#options' => array(
COMMENT_NOTIFY_NODE => t('All comments'),
COMMENT_NOTIFY_COMMENT => t('Replies to my comment')
)
);
$available_options[COMMENT_NOTIFY_DISABLED] = t('No notifications');
$available_options += _comment_notify_options();
$form['comment_notify_settings']['comment_notify_default_anon_mailalert'] = array(
'#type' => 'select',
'#title' => t('Default state for the notification selection box for anonymous users'),
'#return_value' => 1,
'#default_value' => variable_get('comment_notify_default_anon_mailalert', COMMENT_NOTIFY_NODE),
'#options' => $available_options,
);
$form['comment_notify_settings']['comment_notify_default_registered_mailalert'] = array(
'#type' => 'select',
'#title' => t('Default state for the notification selection box for registered users'),
'#return_value' => 1,
'#default_value' => variable_get('comment_notify_default_registered_mailalert', COMMENT_NOTIFY_NODE),
'#description' => t('This flag presets the flag for the follow-up notification on the form that anon users will see when posting a comment'),
'#options' => $available_options,
);
$form['comment_notify_settings']['node_notify_default_mailalert'] = array(
'#type' => 'checkbox',
'#title' => t('Subscribe users to their node follow-up notification emails by default'),
'#default_value' => variable_get('node_notify_default_mailalert', FALSE),
'#description' => t('If this is checked, new users will receive e-mail notifications for follow-ups on their nodes by default until they individually disable the feature.'),
);
$form['comment_notify_settings']['comment_notify_default_mailtext'] = array(
'#type' => 'textarea',
'#title' => t('Default mail text for sending out notifications to commenters'),
'#description' => t(
'You can use the following variables to be replaced:
- !commname = the username who posted the comment
- !commtext = the text of the posted comment
- !commsubj = the subject of the posted comment
- !comment_url = the full url of the post and comment - note: if you have paging enabled, this does not work correct - set your max comments per page so that all fit on one page or reverse order them
- !node_title = the title of the node that was commented on
- !node_teaser = the teaser of the node that was commented on
- !node_body = the body of the node that was commented on
- !mission = site_mission text
- !name = username receiving the alert
- !site = your site
- !uri = base_url of site
- !uri_brief = base_url of site w/o http
- !date = the current time
- !login_uri uri to login the user
- !edit_uri = uri to edit user profile
- !link1 the QUICKLINK to disable future follow-up notifications for the user
'
),
'#default_value' => variable_get('comment_notify_default_mailtext', t(DEFAULT_MAILTEXT)),
'#return_value' => 1,
'#cols' => 80,
'#rows' => 15
);
$form['comment_notify_settings']['node_notify_default_mailtext'] = array(
'#type' => 'textarea',
'#title' => t('Default mail text for sending out the notifications to node authors'),
'#description' => t(
'You can use the following variables to be replaced:
- !commname = the username who posted the comment
- !commtext = the text of the posted comment
- !commsubj = the subject of the posted comment
- !comment_url = the full url of the post and comment - note: if you have paging enabled, this does not work correct - set your max comments per page so that all fit on one page or reverse order them
- !node_title = the title of the node that was commented on
- !node_teaser = the teaser of the node that was commented on
- !node_body = the body of the node that was commented on
- !mission = site_mission text
- !name = username receiving the alert
- !site = your site
- !uri = base_url of site
- !uri_brief = base_url of site w/o http
- !date = the current time
- !login_uri uri to login the user
- !edit_uri = uri to edit user profile
'
),
'#default_value' => variable_get('node_notify_default_mailtext', t(AUTHOR_MAILTEXT)),
'#return_value' => 1,
'#cols' => 80,
'#rows' => 15
);
$form['#validate'] = array('comment_notify_settings_validate');
return system_settings_form($form);
}
function comment_notify_settings_validate($form, &$form_state) {
$sum_enabled = 0;
foreach ($form_state['values']['comment_notify_available_alerts'] as $enabled) {
$sum_enabled += $enabled;
}
if (!$sum_enabled) {
form_set_error('comment_notify_available_alerts', 'You must enable at least one subscription mode.');
}
}