<?php // $Id: header.lib.php 11647 2009-03-04 10:48:30Z zefredz $

    // vim: expandtab sw=4 ts=4 sts=4:
    
    /**
     * Class used to configure and display the page header
     *
     * @version     1.9 $Revision: 11647 $
     * @copyright   2001-2007 Universite catholique de Louvain (UCL)
     * @author      Claroline Team <info@claroline.net>
     * @author      Frederic Minne <zefredz@claroline.net>
     * @license     http://www.gnu.org/copyleft/gpl.html
     *              GNU GENERAL PUBLIC LICENSE version 2 or later
     * @package     DISPLAY
     */
    
    if ( count( get_included_files() ) == 1 )
    {
        die( 'The file ' . basename(__FILE__) . ' cannot be accessed directly, use include instead' );
    }
    
    FromKernel::uses( 'core/loader.lib' );
    
    class ClaroHeader extends CoreTemplate
    {
        private static $instance = false;
        
        private $_htmlXtraHeaders;
        private $_httpXtraHeaders;
        
        /**
         * Constructor
         */
        public function __construct()
        {
            parent::__construct('header.tpl.php');
            $this->_htmlXtraHeaders = array();
            $this->_httpXtraHeaders = array();
        }
        
        public static function getInstance()
        {
            if ( ! ClaroHeader::$instance )
            {
                ClaroHeader::$instance = new ClaroHeader;
            }

            return ClaroHeader::$instance;
        }
        
        /**
         * Add extra HTML header elements
         *
         * @param   string $header header to add
         */
        public function addHtmlHeader( $header )
        {
            $this->_htmlXtraHeaders[] = $header;
        }
        
        /**
         * Add inline javascript code to HTML head
         *
         * @param   string $script javascript code
         */
        public function addInlineJavascript( $script )
        {
            if ( false === strpos( $script, '<script' ) )
            {
                $script = "<script type=\"text/javascript\">\n{$script}\n</script>";
            }
            
            $this->addHtmlHeader( $script );
        }
        
        /**
         * Add inline css style to HTML head
         *
         * @param   string $style css style
         */
        public function addInlineStyle( $style )
        {
            if ( false === strpos( $style, '<style' ) )
            {
                $style = "<style type=\"text/css\">\n{$style}\n</style>";
            }
            
            $this->addHtmlHeader( $style );
        }

        /**
         * Add extra HTTP header elements
         *
         * @param   string $header HTTP header
         */
        public function addHttpHeader( $header )
        {
            $this->_httpXtraHeaders[] = $header;
        }
        
        /**
         * Send HTTP headers to the client
         */
        public function sendHttpHeaders()
        {
            if (! is_null(get_locale('charset')) )
            {
                header('Content-Type: text/html; charset='. get_locale('charset'));
            }

            if ( !empty($this->_httpXtraHeaders) )
            {
                foreach( $this->_httpXtraHeaders as $httpHeader )
                {
                    header( $httpHeader );
                }
            }
        }
        
        /**
         * Retrieve variables used by the old header script for compatibility
         * with old scripts
         */
        private function _globalVarsCompat()
        {
            if ( isset( $GLOBALS['htmlHeadXtra'] ) && !empty($GLOBALS['htmlHeadXtra']) )
            {
                $this->_htmlXtraHeaders = array_merge($this->_htmlXtraHeaders, $GLOBALS['htmlHeadXtra'] );
            }
            
            if ( isset( $GLOBALS['httpHeadXtra'] ) && !empty($GLOBALS['httpHeadXtra']) )
            {
                $this->_httpXtraHeaders = array_merge($this->_httpXtraHeaders, $GLOBALS['httpHeadXtra'] );
            }
            
            if ( isset( $GLOBALS['nameTools'] ) && !empty($GLOBALS['nameTools']) )
            {
                $this->_nameTools = $GLOBALS['nameTools'];
            }
        }
        
        
        /**
         * Render the HTML page header
         * @return  string
         */
        public function render()
        {
            $this->_globalVarsCompat();
            
            $titlePage = '';

            if(!empty($this->_nameTools))
            {
                $titlePage .= $this->_nameTools . ' - ';
            }

            if(claro_is_in_a_course() && claro_get_current_course_data('officialCode') != '')
            {
                $titlePage .= claro_get_current_course_data('officialCode') . ' - ';
            }

            $titlePage .= get_conf('siteName');
            
            $this->assign( 'pageTitle', $titlePage );
            
            if ( true === get_conf( 'warnSessionLost', true ) && claro_get_current_user_id() )
            {
                $this->assign( 'warnSessionLost',
"function claro_session_loss_countdown(sessionLifeTime){
    var chrono = setTimeout('claro_warn_of_session_loss()', sessionLifeTime * 1000);
}

function claro_warn_of_session_loss() {
    alert('" . clean_str_for_javascript (get_lang('WARNING ! You have just lost your session on the server.') . "\n"
             . get_lang('Copy any text you are currently writing and paste it outside the browser')) . "');
}
" );
            }
            else
            {
                $this->assign( 'warnSessionLost', '' );
            }
            
            $htmlXtraHeaders = '';
            
            if ( !empty( $this->_htmlXtraHeaders ) )
            {
                $htmlXtraHeaders .= implode ( "\n", $this->_htmlXtraHeaders );
            }

            $this->assign( 'htmlScriptDefinedHeaders', $htmlXtraHeaders );
            
            return parent::render() . "\n";
        }
    }
