Sets a message to display to the user.
Messages are stored in a session variable and displayed in page.tpl.php via the $messages theme variable.
Example usage:
drupal_set_message(t('An error occurred and processing did not complete.'), 'error');
string $message: (optional) The translated message to be displayed to the user. For consistency with other messages, it should begin with a capital letter and end with a period.
string $type: (optional) The message's type. Defaults to 'status'. These values are supported:
bool $repeat: (optional) If this is FALSE and the message is already set, then the message won't be repeated. Defaults to TRUE.
array|null A multidimensional array with keys corresponding to the set message types. The indexed array values of each contain the set messages for that type. Or, if there are no messages set, the function returns NULL.
function drupal_set_message($message = NULL, $type = 'status', $repeat = TRUE) {
if ($message || $message === '0' || $message === 0) {
if (!isset($_SESSION['messages'][$type])) {
$_SESSION['messages'][$type] = array();
}
if ($repeat || !in_array($message, $_SESSION['messages'][$type])) {
$_SESSION['messages'][$type][] = $message;
}
// Mark this page as being uncacheable.
drupal_page_is_cacheable(FALSE);
}
// Messages not set when DB connection fails.
return isset($_SESSION['messages']) ? $_SESSION['messages'] : NULL;
}