cm = get_coursemodule_from_id('chat', $id))) {
sloodle_debug("Failed to load course module instance #$id.
");
return false;
}
// Make sure the module is visible
if ($this->cm->visible == 0) {
sloodle_debug("Error: course module instance #$id not visible.
");
return false;
}
// Load from the primary table: chat instance
if (!($this->moodle_chat_instance = sloodle_get_record('chat', 'id', $this->cm->instance))) {
sloodle_debug("Failed to load chatroom with instance ID #{$cm->instance}.
");
return false;
}
return true;
}
/**
* Gets a recent history of messages from the chatroom.
* @param int $time How far back to search the database (in seconds) (default: 1 minute)
* @return array A numeric array of {@link SloodleChatMessage} object, in order of oldest to newest
*/
function get_chat_history($time = 60)
{
// Calculate the earliest acceptable timestamp
$earliest = time() - $time;
// Get all message records for this chatroom
$recs = sloodle_get_records_select_params('chat_messages', "chatid = ? AND timestamp >= ?", array($this->moodle_chat_instance->id, $earliest), 'timestamp ASC');
if (!$recs) return array();
// We'll need to lookup all the user data.
// Cache the user records so we don't need to duplicate searches.
// This will be an associative array of user ID's to SloodleUser objects.
$usercache = array();
// Prepare an array of chat message objects
$chatmessages = array();
// Go through each result
foreach ($recs as $r) {
// Do we already have the current user cached?
if (!isset($usercache[$r->userid])) {
// No - query the database
$usercache[$r->userid] = new SloodleUser($this->_session);
if ($usercache[$r->userid]->load_user($r->userid)) {
// Attempt to load any linked avatar data too
$usercache[$r->userid]->load_linked_avatar();
}
}
// Construct and add a message object
$chatmessages[] = new SloodleChatMessage($r->id, $r->message, $usercache[$r->userid], $r->timestamp);
}
return $chatmessages;
}
/**
* Adds a new chat message.
* Note: if the $author parameter is omitted or invalid, then the function will attempt to use the {@link SloodleUser} member
* of the current {@link SloodleSession} object;
* If that is unavailable, then it will try to use the user currently 'logged-in' to the VLE (i.e. the $USER variable in Moodle).
* If all else fails, it will attempt to attribute the message to the guest user.
* @param string $message The text of the message.
* @param mixed $user The user who wrote the message -- either a VLE user ID or (preferably) a {@link SloodleUser} object. If null, then the user in the current SloodleSession object will be used. At that fails, then the guest user is used if possible.
* @param int $timestamp Timestamp of the message. If omitted or <= 0 then the current timestamp is used
* @return bool True if successful, or false otherwise
*/
function add_message($message, $user = null, $timestamp = null)
{
// Ignore empty messages
if (empty($message)) return false;
// Make sure the message is safe
$message = clean_text(stripslashes($message));
// We need to get the user ID for the message
$userid = 0;
// Has a user object been provided?
if (is_object($user)) {
// Yes - grab the user ID
$userid = $user->get_user_id();
}
else if ($user != null) {
// May be an ID
$userid = (int)$user;
}
// Did we end up with a valid user ID?
if ((int)$userid <= 0) {
// No - do we have a user in the session parameter?
if (isset($this->_session->user)) {
// Store the user ID
$userid = $this->_session->user->get_user_id();
}
}
// Are we still lacking a valid user?
if ((int)$userid <= 0) {
// Yes - user the guest user
$guest = guest_user();
if ($guest) $userid = $guest->id;
}
// Prepare the timestamp variable if necessary
if (is_null($timestamp)) $timestamp = time();
// Create a chat message record object
$rec = new stdClass();
$rec->chatid = $this->moodle_chat_instance->id;
$rec->userid = $userid;
$rec->message = $message;
$rec->timestamp = $timestamp;
// Attempt to insert the chat message
$result = sloodle_insert_record('chat_messages', $rec);
if (!$result) return false;
if (SLOODLE_IS_ENVIRONMENT_MOODLE_2) {
$result = sloodle_insert_record('chat_messages_current', $rec);
if (!$result) return false;
}
if (!is_null($this->_session->active_object)) {
$this->_session->active_object->process_interaction('default', 1, $userid, null);
// TODO: Maybe we should set a side effect code here?
}
// We successfully added a chat message
// If possible, add an appropriate side effect code to our response
if (isset($this->_session->response)) {
$this->_session->response->add_side_effect(10101);
}
return true;
}
// ACCESSORS //
/**
* Gets the name of this module instance.
* @return string The name of this controller
*/
function get_name()
{
return $this->moodle_chat_instance->name;
}
/**
* Gets the intro description of this module instance, if available.
* @return string The intro description of this controller
*/
function get_intro()
{
return $this->moodle_chat_instance->intro;
}
/**
* Gets the identifier of the course this controller belongs to.
* @return mixed Course identifier. Type depends on VLE. (In Moodle, it will be an integer).
*/
function get_course_id()
{
return (int)$this->moodle_chat_instance->course;
}
/**
* Gets the time at which this instance was created, or 0 if unknown.
* @return int Timestamp
*/
function get_creation_time()
{
return 0;
}
/**
* Gets the time at which this instance was last modified, or 0 if unknown.
* @return int Timestamp
*/
function get_modification_time()
{
return $this->moodle_chat_instance->timemodified;
}
/**
* Gets the short type name of this instance.
* @return string
*/
static function get_type()
{
return 'chat';
}
/**
* Gets the full type name of this instance, according to the current language pack, if available.
* Note: should be overridden by sub-classes.
* @return string Full type name if possible, or the short name otherwise.
*/
static function get_type_full()
{
return get_string('modulename', 'chat');
}
}
/**
* Represents a single chat message
* @package sloodle
*/
class SloodleChatMessage
{
/**
* Constructor - initialises members.
* @param mixed $id The ID of this message - type depends on VLE, but is typically an integer
* @param string $message The chat message
* @param SloodleUser $user The user who wrote the message
* @param int $timestamp The timestamp of the message
*/
function SloodleChatMessage($id, $message, $user, $timestamp)
{
$this->id = $id;
$this->message = $message;
$this->user = $user;
$this->timestamp = $timestamp;
}
/**
* Accessor - set all members in a single call.
* @param mixed $id The ID of this message - type depends on VLE, but is typically an integer
* @param string $message The chat message
* @param SloodleUser $user The user who wrote the message
* @param int $timestamp The timestamp of the message
*/
function set($id, $message, $user, $timestamp)
{
$this->id = $id;
$this->message = $message;
$this->user = $user;
$this->timestamp = $timestamp;
}
/**
* The ID of the message.
* The type depends on the VLE, but typically is an integer.
* @var mixed
* @access public
*/
var $id = 0;
/**
* The text of the message.
* @var string
* @access public
*/
var $message = '';
/**
* The user who wrote this message.
* @var SloodleUser
* @access public
*/
var $user = null;
/**
* Timestamp of the message.
* @var int
* @access public
*/
var $timestamp = 0;
}