class.thread.php

<?php
/*********************************************************************
    class.thread.php

    Ticket thread
    XXX: Please DO NOT add any ticket related logic! use ticket class.

    Peter Rotich <peter@osticket.com>
    Copyright (c)  2006-2013 osTicket
    http://www.osticket.com

    Released under the GNU General Public License WITHOUT ANY WARRANTY.
    See LICENSE.TXT for details.

    vim: expandtab sw=4 ts=4 sts=4:
**********************************************************************/
include_once(INCLUDE_DIR.'class.ticket.php');

//Ticket thread.
class Thread {

    var $id; // same as ticket ID.
    var $ticket;

    function Thread($ticket) {

        $this->ticket = $ticket;

        $this->id = 0;

        $this->load();
    }

    function load() {

        if(!$this->getTicketId())
            return null;

        $sql='SELECT ticket.ticket_id as id '
            .' ,count(DISTINCT attach.attach_id) as attachments '
            .' ,count(DISTINCT message.id) as messages '
            .' ,count(DISTINCT response.id) as responses '
            .' ,count(DISTINCT note.id) as notes '
            .' FROM '.TICKET_TABLE.' ticket '
            .' LEFT JOIN '.TICKET_ATTACHMENT_TABLE.' attach ON ('
                .'ticket.ticket_id=attach.ticket_id) '
            .' LEFT JOIN '.TICKET_THREAD_TABLE.' message ON ('
                ."ticket.ticket_id=message.ticket_id AND message.thread_type = 'M') "
            .' LEFT JOIN '.TICKET_THREAD_TABLE.' response ON ('
                ."ticket.ticket_id=response.ticket_id AND response.thread_type = 'R') "
            .' LEFT JOIN '.TICKET_THREAD_TABLE.' note ON ( '
                ."ticket.ticket_id=note.ticket_id AND note.thread_type = 'N') "
            .' WHERE ticket.ticket_id='.db_input($this->getTicketId())
            .' GROUP BY ticket.ticket_id';

        if(!($res=db_query($sql)) || !db_num_rows($res))
            return false;

        $this->ht = db_fetch_array($res);

        $this->id = $this->ht['id'];

        return true;
    }

    function getId() {
        return $this->id;
    }

    function getTicketId() {
        return $this->getTicket()?$this->getTicket()->getId():0;
    }

    function getTicket() {
        return $this->ticket;
    }

    function getNumAttachments() {
        return $this->ht['attachments'];
    }

    function getNumMessages() {
        return $this->ht['messages'];
    }

    function getNumResponses() {
        return $this->ht['responses'];
    }

    function getNumNotes() {
        return $this->ht['notes'];
    }

    function getCount() {
        return $this->getNumMessages() + $this->getNumResponses();
    }

    function getMessages() {
        return $this->getEntries('M');
    }

    function getResponses() {
        return $this->getEntries('R');
    }

    function getNotes() {
        return $this->getEntries('N');
    }

    function getEntries($type, $order='ASC') {

        if(!$order || !in_array($order, array('DESC','ASC')))
            $order='ASC';

        $sql='SELECT thread.* '
            .' ,count(DISTINCT attach.attach_id) as attachments '
            .' FROM '.TICKET_THREAD_TABLE.' thread '
            .' LEFT JOIN '.TICKET_ATTACHMENT_TABLE.' attach
                ON (thread.ticket_id=attach.ticket_id
                        AND thread.id=attach.ref_id
                        AND thread.thread_type=attach.ref_type) '
            .' WHERE  thread.ticket_id='.db_input($this->getTicketId());

        if($type && is_array($type))
            $sql.=' AND thread.thread_type IN('.implode(',', db_input($type)).')';
        elseif($type)
            $sql.=' AND thread.thread_type='.db_input($type);

        $sql.=' GROUP BY thread.id '
             .' ORDER BY thread.created '.$order;

        $entries = array();
        if(($res=db_query($sql)) && db_num_rows($res))
            while($rec=db_fetch_array($res))
                $entries[] = $rec;

        return $entries;
    }

    function getEntry($id) {
        return ThreadEntry::lookup($id, $this->getTicketId());
    }

    function addNote($vars, &$errors) {

        //Add ticket Id.
        $vars['ticketId'] = $this->getTicketId();

        // DELME: When HTML / rich-text is supported
        $vars['title'] = Format::htmlchars($vars['title']);
        $vars['body'] = Format::htmlchars($vars['body']);

        return Note::create($vars, $errors);
    }

    function addMessage($vars, &$errors) {

        $vars['ticketId'] = $this->getTicketId();
        $vars['staffId'] = 0;

        // DELME: When HTML / rich-text is supported
        $vars['title'] = Format::htmlchars($vars['title']);
        $vars['body'] = Format::htmlchars($vars['body']);

        return Message::create($vars, $errors);
    }

    function addResponse($vars, &$errors) {

        $vars['ticketId'] = $this->getTicketId();

        // DELME: When HTML / rich-text is supported
        $vars['title'] = Format::htmlchars($vars['title']);
        $vars['body'] = Format::htmlchars($vars['body']);

        return Response::create($vars, $errors);
    }

    function deleteAttachments() {

        $deleted=0;
        // Clear reference table
        $res=db_query('DELETE FROM '.TICKET_ATTACHMENT_TABLE.' WHERE ticket_id='.db_input($this->getTicketId()));
        if ($res && db_affected_rows())
            $deleted = AttachmentFile::deleteOrphans();

        return $deleted;
    }

    function delete() {

        /* XXX: Leave this out until TICKET_EMAIL_INFO_TABLE has a primary
         *      key
        $sql = 'DELETE mid.* FROM '.TICKET_EMAIL_INFO_TABLE.' mid
            INNER JOIN '.TICKET_THREAD_TABLE.' thread ON (thread.id = mid.message_id)
            WHERE thread.ticket_id = '.db_input($this->getTicketId());
        db_query($sql);
         */

        $res=db_query('DELETE FROM '.TICKET_THREAD_TABLE.' WHERE ticket_id='.db_input($this->getTicketId()));
        if(!$res || !db_affected_rows())
            return false;

        $this->deleteAttachments();

        return true;
    }

    /* static */
    function lookup($ticket) {

        return ($ticket
                && is_object($ticket)
                && ($thread = new Thread($ticket))
                && $thread->getId()
                )?$thread:null;
    }
}


Class ThreadEntry {

    var $id;
    var $ht;

    var $staff;
    var $ticket;

    var $attachments;


    function ThreadEntry($id, $type='', $ticketId=0) {
        $this->load($id, $type, $ticketId);
    }

    function load($id=0, $type='', $ticketId=0) {

        if(!$id && !($id=$this->getId()))
            return false;

        $sql='SELECT thread.*, info.email_mid '
            .' ,count(DISTINCT attach.attach_id) as attachments '
            .' FROM '.TICKET_THREAD_TABLE.' thread '
            .' LEFT JOIN '.TICKET_EMAIL_INFO_TABLE.' info
                ON (thread.id=info.message_id) '
            .' LEFT JOIN '.TICKET_ATTACHMENT_TABLE.' attach
                ON (thread.ticket_id=attach.ticket_id
                        AND thread.id=attach.ref_id
                        AND thread.thread_type=attach.ref_type) '
            .' WHERE  thread.id='.db_input($id);

        if($type)
            $sql.=' AND thread.thread_type='.db_input($type);

        if($ticketId)
            $sql.=' AND thread.ticket_id='.db_input($ticketId);

        $sql.=' GROUP BY thread.id ';

        if(!($res=db_query($sql)) || !db_num_rows($res))
            return false;

        $this->ht = db_fetch_array($res);
        $this->id = $this->ht['id'];

        $this->staff = $this->ticket = null;
        $this->attachments = array();

        return true;
    }

    function reload() {
        return $this->load();
    }

    function getId() {
        return $this->id;
    }

    function getPid() {
        return $this->ht['pid'];
    }

    function getType() {
        return $this->ht['thread_type'];
    }

    function getSource() {
        return $this->ht['source'];
    }

    function getPoster() {
        return $this->ht['poster'];
    }

    function getTitle() {
        return $this->ht['title'];
    }

    function getBody() {
        return $this->ht['body'];
    }

    function getCreateDate() {
        return $this->ht['created'];
    }

    function getUpdateDate() {
        return $this->ht['updated'];
    }

    function getNumAttachments() {
        return $this->ht['attachments'];
    }

    function getTicketId() {
        return $this->ht['ticket_id'];
    }

    function getEmailMessageId() {
        return $this->ht['email_mid'];
    }

    function getTicket() {

        if(!$this->ticket && $this->getTicketId())
            $this->ticket = Ticket::lookup($this->getTicketId());

        return $this->ticket;
    }

    function getStaffId() {
        return $this->ht['staff_id'];
    }

    function getStaff() {

        if(!$this->staff && $this->getStaffId())
            $this->staff = Staff::lookup($this->getStaffId());

        return $this->staff;
    }

    function getEmailHeader() {
        return $this->ht['headers'];
    }

    function isAutoResponse() {
        return $this->getEmailHeader()?TicketFilter::isAutoResponse($this->getEmailHeader()):false;
    }

    //Web uploads - caller is expected to format, validate and set any errors.
    function uploadFiles($files) {

        if(!$files || !is_array($files))
            return false;

        $uploaded=array();
        foreach($files as $file) {
            if($file['error'] && $file['error']==UPLOAD_ERR_NO_FILE)
                continue;

            if(!$file['error']
                    && ($id=AttachmentFile::upload($file))
                    && $this->saveAttachment($id))
                $uploaded[]=$id;
            else {
                if(!$file['error'])
                    $error = 'Unable to upload file - '.$file['name'];
                elseif(is_numeric($file['error']))
                    $error ='Error #'.$file['error']; //TODO: Transplate to string.
                else
                    $error = $file['error'];
                /*
                 Log the error as an internal note.
                 XXX: We're doing it here because it will eventually become a thread post comment (hint: comments coming!)
                 XXX: logNote must watch for possible loops
               */
                $this->getTicket()->logNote('File Upload Error', $error, 'SYSTEM', false);
            }

        }

        return $uploaded;
    }

    function importAttachments($attachments) {

        if(!$attachments || !is_array($attachments))
            return null;

        $files = array();
        foreach($attachments as  $attachment)
            if(($id=$this->importAttachment($attachment)))
                $files[] = $id;

        return $files;
    }

    /* Emailed & API attachments handler */
    function importAttachment($attachment) {

        if(!$attachment || !is_array($attachment))
            return null;

        $id=0;
        if (!$attachment['error'] && ($id=$this->saveAttachment($attachment)))
            $files[] = $id;
        else {
            $error = $attachment['error'];

            if(!$error)
                $error = 'Unable to import attachment - '.$attachment['name'];

            $this->getTicket()->logNote('File Import Error', $error, 'SYSTEM', false);
        }

        return $id;
    }

   /*
    Save attachment to the DB.
    @file is a mixed var - can be ID or file hashtable.
    */
    function saveAttachment($file) {

        if(!($fileId=is_numeric($file)?$file:AttachmentFile::save($file)))
            return 0;

        $sql ='INSERT INTO '.TICKET_ATTACHMENT_TABLE.' SET created=NOW() '
             .' ,file_id='.db_input($fileId)
             .' ,ticket_id='.db_input($this->getTicketId())
             .' ,ref_id='.db_input($this->getId())
             .' ,ref_type='.db_input($this->getType());

        return (db_query($sql) && ($id=db_insert_id()))?$id:0;
    }

    function saveAttachments($files) {
        $ids=array();
        foreach($files as $file)
           if(($id=$this->saveAttachment($file)))
               $ids[] = $id;

        return $ids;
    }

    function getAttachments() {

        if($this->attachments)
            return $this->attachments;

        //XXX: inner join the file table instead?
        $sql='SELECT a.attach_id, f.id as file_id, f.size, f.hash as file_hash, f.name '
            .' FROM '.FILE_TABLE.' f '
            .' INNER JOIN '.TICKET_ATTACHMENT_TABLE.' a ON(f.id=a.file_id) '
            .' WHERE a.ticket_id='.db_input($this->getTicketId())
            .' AND a.ref_id='.db_input($this->getId())
            .' AND a.ref_type='.db_input($this->getType());

        $this->attachments = array();
        if(($res=db_query($sql)) && db_num_rows($res)) {
            while($rec=db_fetch_array($res))
                $this->attachments[] = $rec;
        }

        return $this->attachments;
    }

    function getAttachmentsLinks($file='attachment.php', $target='', $separator=' ') {

        $str='';
        foreach($this->getAttachments() as $attachment ) {
            /* The hash can be changed  but must match validation in @file */
            $hash=md5($attachment['file_id'].session_id().$attachment['file_hash']);
            $size = '';
            if($attachment['size'])
                $size=sprintf('<em>(%s)</em>', Format::file_size($attachment['size']));

            $str.=sprintf('<a class="Icon file" href="%s?id=%d&h=%s" target="%s">%s</a>%s&nbsp;%s',
                    $file, $attachment['attach_id'], $hash, $target, Format::htmlchars($attachment['name']), $size, $separator);
        }

        return $str;
    }
    /**
     * postEmail
     *
     * After some security and sanity checks, attaches the body and subject
     * of the message in reply to this thread item
     *
     * Parameters:
     * mailinfo - (array) of information about the email, with at least the
     *          following keys
     *      - mid - (string) email message-id
     *      - name - (string) personal name of email originator
     *      - email - (string<email>) originating email address
     *      - subject - (string) email subject line (decoded)
     *      - body - (string) email message body (decoded)
     */
    function postEmail($mailinfo) {
        // +==================+===================+=============+
        // | Orig Thread-Type | Reply Thread-Type | Requires    |
        // +==================+===================+=============+
        // | *                | Message (M)       | From: Owner |
        // | *                | Note (N)          | From: Staff |
        // | Response (R)     | Message (M)       |             |
        // | Message (M)      | Response (R)      | From: Staff |
        // +------------------+-------------------+-------------+

        if (!$ticket = $this->getTicket())
            // Kind of hard to continue a discussion without a ticket ...
            return false;

        // Make sure the email is NOT already fetched... (undeleted emails)
        elseif ($this->getEmailMessageId() == $mailinfo['mid'])
            // Reporting success so the email can be moved or deleted.
            return true;

        $vars = array(
            'mid' =>    $mailinfo['mid'],
            'header' => $mailinfo['header'],
            'ticketId' => $ticket->getId(),
            'poster' => $mailinfo['name'],
            'origin' => 'Email',
            'source' => 'Email',
            'ip' =>     '',
            'reply_to' => $this,
        );

        if (isset($mailinfo['attachments']))
            $vars['attachments'] = $mailinfo['attachments'];

        $body = $mailinfo['message'];

        // Disambiguate if the user happens also to be a staff member of the
        // system. The current ticket owner should _always_ post messages
        // instead of notes or responses
        if (strcasecmp($mailinfo['email'], $ticket->getEmail()) == 0) {
            $vars['message'] = $body;
            return $ticket->postMessage($vars, 'Email');
        }
        elseif ($staff_id = Staff::getIdByEmail($mailinfo['email'])) {
            $vars['staffId'] = $staff_id;
            $poster = Staff::lookup($staff_id);
            $errors = array();
            $vars['note'] = $body;
            return $ticket->postNote($vars, $errors, $poster);
        }
        elseif (Email::getIdByEmail($mailinfo['email'])) {
            // Don't process the email -- it came FROM this system
            return true;
        }
        // TODO: Consider security constraints
        else {
            $vars['message'] = sprintf("Received From: %s\n\n%s",
                $mailinfo['email'], $body);
            return $ticket->postMessage($vars, 'Email');
        }
        // Currently impossible, but indicate that this thread object could
        // not append the incoming email.
        return false;
    }

    /* Returns file names with id as key */
    function getFiles() {

        $files = array();
        foreach($this->getAttachments() as $attachment)
            $files[$attachment['file_id']] = $attachment['name'];

        return $files;
    }


    /* save email info
     * TODO: Refactor it to include outgoing emails on responses.
     */

    function saveEmailInfo($vars) {

        if(!$vars || !$vars['mid'])
            return 0;

        $sql='INSERT INTO '.TICKET_EMAIL_INFO_TABLE
            .' SET message_id='.db_input($this->getId()) //TODO: change it to thread_id
            .', email_mid='.db_input($vars['mid']); //TODO: change it to mid.
        if (isset($vars['header']))
            $sql .= ', headers='.db_input($vars['header']);

        $this->ht['email_mid'] = $vars['mid'];

        return db_query($sql)?db_insert_id():0;
    }


    /* variables */

    function asVar() {
        return $this->getBody();
    }

    function getVar($tag) {
        global $cfg;

        if($tag && is_callable(array($this, 'get'.ucfirst($tag))))
            return call_user_func(array($this, 'get'.ucfirst($tag)));

        switch(strtolower($tag)) {
            case 'create_date':
                return Format::date(
                        $cfg->getDateTimeFormat(),
                        Misc::db2gmtime($this->getCreateDate()),
                        $cfg->getTZOffset(),
                        $cfg->observeDaylightSaving());
                break;
            case 'update_date':
                return Format::date(
                        $cfg->getDateTimeFormat(),
                        Misc::db2gmtime($this->getUpdateDate()),
                        $cfg->getTZOffset(),
                        $cfg->observeDaylightSaving());
                break;
        }

        return false;
    }

    /* static calls */

    function lookup($id, $tid=0, $type='') {
        return ($id
                && is_numeric($id)
                && ($e = new ThreadEntry($id, $type, $tid))
                && $e->getId()==$id
                )?$e:null;
    }

    /**
     * Parameters:
     * mailinfo (hash<String>) email header information. Must include keys
     *  - "mid" => Message-Id header of incoming mail
     *  - "in-reply-to" => Message-Id the email is a direct response to
     *  - "references" => List of Message-Id's the email is in response
     *  - "subject" => Find external ticket number in the subject line
     */
    function lookupByEmailHeaders($mailinfo) {
        // Search for messages using the References header, then the
        // in-reply-to header
        $search = 'SELECT message_id FROM '.TICKET_EMAIL_INFO_TABLE
               . ' WHERE email_mid=%s ORDER BY message_id DESC';

        if ($id = db_result(db_query(
                sprintf($search, db_input($mailinfo['mid'])))))
            return ThreadEntry::lookup($id);

        foreach (array('mid', 'in-reply-to', 'references') as $header) {
            $matches = array();
            if (!isset($mailinfo[$header]) || !$mailinfo[$header])
                continue;
            // Header may have multiple entries (usually separated by
            // semi-colons (;))
            elseif (!preg_match_all('/<[^>@]+@[^>]+>/', $mailinfo[$header],
                        $matches))
                continue;

            foreach ($matches[0] as $mid) {
                $res = db_query(sprintf($search, db_input($mid)));
                while (list($id) = db_fetch_row($res)) {
                    if ($t = ThreadEntry::lookup($id))
                        return $t;
                }
            }
        }

        // Search for ticket by the [#123456] in the subject line
        // This is the last resort -  emails must match to avoid message
        // injection by third-party.
        $subject = $mailinfo['subject'];
        $match = array();
        if ($subject && $mailinfo['email']
                && preg_match("/\[#([0-9]{1,10})\]/", $subject, $match)
                && ($tid = Ticket::getIdByExtId((int)$match[1], $mailinfo['email']))
                )
            // Return last message for the thread
            return Message::lastByTicketId($tid);

        return null;
    }

    //new entry ... we're trusting the caller to check validity of the data.
    function create($vars) {
        global $cfg;

        //Must have...
        if(!$vars['ticketId'] || !$vars['type'] || !in_array($vars['type'], array('M','R','N')))
            return false;

        $sql=' INSERT INTO '.TICKET_THREAD_TABLE.' SET created=NOW() '
            .' ,thread_type='.db_input($vars['type'])
            .' ,ticket_id='.db_input($vars['ticketId'])
            .' ,title='.db_input(Format::sanitize($vars['title'], true))
            .' ,body='.db_input(Format::sanitize($vars['body'], true))
            .' ,staff_id='.db_input($vars['staffId'])
            .' ,poster='.db_input($vars['poster'])
            .' ,source='.db_input($vars['source']);

        if(isset($vars['pid']))
            $sql.=' ,pid='.db_input($vars['pid']);
        // Check if 'reply_to' is in the $vars as the previous ThreadEntry
        // instance. If the body of the previous message is found in the new
        // body, strip it out.
        elseif (isset($vars['reply_to'])
                && $vars['reply_to'] instanceof ThreadEntry)
            $sql.=' ,pid='.db_input($vars['reply_to']->getId());

        if($vars['ip_address'])
            $sql.=' ,ip_address='.db_input($vars['ip_address']);

        //echo $sql;
        if(!db_query($sql) || !($entry=self::lookup(db_insert_id(), $vars['ticketId'])))
            return false;

        /************* ATTACHMENTS *****************/

        //Upload/save attachments IF ANY
        if($vars['files']) //expects well formatted and VALIDATED files array.
            $entry->uploadFiles($vars['files']);

        //Emailed or API attachments
        if($vars['attachments'])
            $entry->importAttachments($vars['attachments']);

        //Canned attachments...
        if($vars['cannedattachments'] && is_array($vars['cannedattachments']))
            $entry->saveAttachments($vars['cannedattachments']);

        // Email message id (required for all thread posts)
        if (!isset($vars['mid']))
            $vars['mid'] = sprintf('<%s@%s>', Misc::randCode(24),
                substr(md5($cfg->getUrl()), -10));
        $entry->saveEmailInfo($vars);

        return $entry;
    }

    function add($vars) {
        return ($entry=self::create($vars))?$entry->getId():0;
    }
}

/* Message - Ticket thread entry of type message */
class Message extends ThreadEntry {

    function Message($id, $ticketId=0) {
        parent::ThreadEntry($id, 'M', $ticketId);
    }

    function getSubject() {
        return $this->getTitle();
    }

    function create($vars, &$errors) {
        return self::lookup(self::add($vars, $errors));
    }

    function add($vars, &$errors) {

        if(!$vars || !is_array($vars) || !$vars['ticketId'])
            $errors['err'] = 'Missing or invalid data';
        elseif(!$vars['message'])
            $errors['message'] = 'Message required';

        if($errors) return false;

        $vars['type'] = 'M';
        $vars['body'] = $vars['message'];

        return ThreadEntry::add($vars);
    }

    function lookup($id, $tid=0, $type='M') {

        return ($id
                && is_numeric($id)
                && ($m = new Message($id, $tid))
                && $m->getId()==$id
                )?$m:null;
    }

    function lastByTicketId($ticketId) {

        $sql=' SELECT thread.id FROM '.TICKET_THREAD_TABLE.' thread '
            .' WHERE thread_type=\'M\' AND thread.ticket_id = '.db_input($ticketId)
            .' ORDER BY thread.id DESC LIMIT 1';

        if (($res = db_query($sql)) && ($id = db_result($res)))
            return Message::lookup($id);

        return null;
    }
}

/* Response - Ticket thread entry of type response */
class Response extends ThreadEntry {

    function Response($id, $ticketId=0) {
        parent::ThreadEntry($id, 'R', $ticketId);
    }

    function getSubject() {
        return $this->getTitle();
    }

    function getRespondent() {
        return $this->getStaff();
    }

    function create($vars, &$errors) {
        return self::lookup(self::add($vars, $errors));
    }

    function add($vars, &$errors) {

        if(!$vars || !is_array($vars) || !$vars['ticketId'])
            $errors['err'] = 'Missing or invalid data';
        elseif(!$vars['response'])
            $errors['response'] = 'Response required';

        if($errors) return false;

        $vars['type'] = 'R';
        $vars['body'] = $vars['response'];
        if(!$vars['pid'] && $vars['msgId'])
            $vars['pid'] = $vars['msgId'];

        return ThreadEntry::add($vars);
    }


    function lookup($id, $tid=0, $type='R') {

        return ($id
                && is_numeric($id)
                && ($r = new Response($id, $tid))
                && $r->getId()==$id
                )?$r:null;
    }
}

/* Note - Ticket thread entry of type note (Internal Note) */
class Note extends ThreadEntry {

    function Note($id, $ticketId=0) {
        parent::ThreadEntry($id, 'N', $ticketId);
    }

    function getMessage() {
        return $this->getBody();
    }

    /* static */
    function create($vars, &$errors) {
        return self::lookup(self::add($vars, $errors));
    }

    function add($vars, &$errors) {

        //Check required params.
        if(!$vars || !is_array($vars) || !$vars['ticketId'])
            $errors['err'] = 'Missing or invalid data';
        elseif(!$vars['note'])
            $errors['note'] = 'Note required';

        if($errors) return false;

        //TODO: use array_intersect_key  when we move to php 5 to extract just what we need.
        $vars['type'] = 'N';
        $vars['body'] = $vars['note'];

        return ThreadEntry::add($vars);
    }

    function lookup($id, $tid=0, $type='N') {

        return ($id
                && is_numeric($id)
                && ($n = new Note($id, $tid))
                && $n->getId()==$id
                )?$n:null;
    }
}
?>