listprint_napdf.class.php

Go to the documentation of this file.

<?php
/**
    \file listprint_napdf.class.php
    \version 1.2.16
    \brief This file creates and dumps a generic meeting list in a booklet form.
*/
// Get the napdf class, which is used to fetch the data and construct the file.
require_once ( dirname ( __FILE__ ).'/printableList.class.php' );

/**
    \brief  This creates and manages an instance of the napdf class, and creates
    the PDF file.
*/
class listprint_napdf extends printableList implements IPrintableList
{
    var $weekday_names = null;
    var $pos = array ( 'start' => 1, 'end' => '', 'count' => 0, 'y' => 0, 'weekday' => 1 );
    var $right_offset = 0;
    var $formats = 0;
    var $special_formats = '';
    
    /********************************************************************
        \brief  The constructor for this class does a lot. It creates the instance of the napdf class, gets the data from the
        server, then sorts it. When the constructor is done, the data is ready to be assembled into a PDF.
        
        If the napdf object does not successfully get data from the server, then it is set to null.
    */
    function __construct ( $in_http_vars    ///< The HTTP parameters we'd like to send to the server.
                            )
    {
        include ( dirname ( __FILE__ ).'/listprint_pdf_decls.php' );
        $this->weekday_names = $g_weekday_names;
        $this->page_x = 8;          ///< The width, in inches, of each page
        $this->page_y = 10.5;       ///< The height, in inches, of each page.
        $this->units = 'in';        ///< The measurement units (inches)
        $this->font = 'helvetica';  ///< The font we'll use
        $this->font_size = 10;      ///< The font size we'll use
        $this->orientation = 'P';   ///< The orientation (portrait)
        /// These are the sort keys, for sorting the meetings before display
        $this->sort_keys = array (  'weekday_tinyint' => true,          ///< First, weekday
                                    'start_time' => true,               ///< Finally, the time the meeting starts
                                    'week_starts' => 1                  ///< Our week starts on Sunday (1)
                                    );
        /// These are the parameters that we send over to the root server, in order to get our meetings.
        $this->out_http_vars = array ('do_search' => 'yes',                     ///< Do a search
                                    'bmlt_search_type' => 'advanced',
                                    'advanced_service_bodies' => $in_http_vars['advanced_service_bodies'],
                                    'advanced_formats' => $in_http_vars['advanced_formats'],
                                    'advanced_weekdays' => $in_http_vars['advanced_weekdays'],
                                    'advanced_radius' => $in_http_vars['advanced_radius'],
                                    'advanced_mapmode' => $in_http_vars['advanced_mapmode'],
                                    'long_val' => $in_http_vars['long_val'],
                                    'lat_val' => $in_http_vars['lat_val'],
                                    'geo_width' => $in_http_vars['geo_width'],
                                    'geo_width_km' => $in_http_vars['geo_width_km'],
                                    'long_val' => $in_http_vars['long_val'],
                                    'lat_val' => $in_http_vars['lat_val'],
                                    'SearchString' => $in_http_vars['SearchString'],
                                    'StringSearchIsAnAddress' => $in_http_vars['StringSearchIsAnAddress']
                                    );

        $this->lang_search = array ( 'en' );
        
        napdf::$sort_callback = 'listprint_napdf::sort_meeting_data_callback';
        
        parent::__construct ( $in_http_vars, $this->lang_search );
    }
    /*************************** INTERFACE FUNCTIONS ***************************/
    /********************************************************************
        \brief This function actually assembles the PDF. It does not output it.
        
        \returns a boolean. true if successful.
    */
    function AssemblePDF ()
    {
        $ret = false;
        
        if ( $this->napdf_instance instanceof napdf )
            {
            $this->DrawFormatPage ( );
            $left = true;
            while ( !$this->pos['end'] )
                {
                $this->DrawListPage ( $left );
                $left = !$left;
                }
            $ret = true;
            }
        
        return $ret;
    }
    
    /********************************************************************
    */
    function OutputPDF ()
    {
        $d = date ( "Y_m_d" );
        $this->napdf_instance->Output( "BMLT_PrintableList_$d.pdf", "D" );
    }
    
    /*************************** INTERNAL FUNCTIONS ***************************/
    /********************************************************************
    */
    private static function sort_cmp_formats ($a, $b) 
    {
    $order_array = array(   0=>"O", 1=>"C",
                            2=>"ES", 3=>"B", 4=>"M", 5=>"W", 6=>"GL", 7=>"YP", 8=>"BK", 9=>"IP", 10=>"Pi", 11=>"RF", 12=>"Rr",
                            13=>"So", 14=>"St", 15=>"To", 16=>"Tr", 17=>"OE", 18=>"D", 19=>"SD", 20=>"TW", 21=>"IL",
                            22=>"BL", 23=>"IW", 24=>"BT", 25=>"SG", 26=>"JT",
                            27=>"Ti", 28=>"Sm", 29=>"NS", 30=>"CL", 31=>"CS", 32=>"NC", 33=>"SC", 34=>"CH", 35=>"SL", 36=>"WC" );
    
    if ( in_array ( $a['key_string'], $order_array ) || in_array ( $b['key_string'], $order_array ) )
        {
        return (array_search ( $a['key_string'], $order_array ) < array_search ( $b['key_string'], $order_array )) ? -1 : 1;
        }
    else
        {
        return 0;
        }
    }

    /********************************************************************
        \brief Combines the two languages for a common format display.
        
        \returns a new array, with the format data sorted out. The Spanish
        description is appended to the description by a line feed.
    */
    private static function sort_formats( $in_format_data   ///< An array of format information
                                        )
    {
        $ret = array();
        
        foreach ( $in_format_data as $format )
            {
            if ( $format['lang'] == 'en' )  // We skip the Spanish, and only work on the English.
                {
                $s_desc = ((isset ( $in_format_data[$format['id'].'_es'] )) ? '('.$in_format_data[$format['id'].'_es']['name_string'].') '.$in_format_data[$format['id'].'_es']['description_string'] : null);
                $r_temp = array (   'key_string' => $format['key_string'],
                                    'description_string' => '('.$format['name_string'].') '.$format['description_string']
                                    );
                if ( $s_desc )
                    {
                    $r_temp['description_string'] .= "\n$s_desc";
                    }
                
                array_push ( $ret, $r_temp );
                }
            }
        
        usort ( $ret, 'listprint_napdf::sort_cmp_formats' );
        
        return $ret;
    }

    /********************************************************************
    */
    private function DrawFormatPage ( )
    {
    include ( dirname ( __FILE__ ).'/listprint_pdf_decls.php' );
    $formats = self::sort_formats ( $this->napdf_instance->format_data );

    $this->napdf_instance->SetFont ( $this->font, '', $this->font_size );
    $top = 0.125;
    $left = 0.125;
    $bottom = $this->napdf_instance->h - 0.125;
    $right = $this->napdf_instance->w - 0.125;
    $fontFamily = $this->napdf_instance->FontFamily;
    $fontSize = $this->napdf_instance->FontSizePt;
    $heading_height = $fontSize + 2;
    $height = ($heading_height/72) + 0.02;
    $fontSizeSmaller = $fontSize - 1;
    $fSize = $fontSizeSmaller / 72;
    $this->right_offset = 0.4;
    $space_needed = (($fontSizeSmaller / 72) * 3) + 0.02;
    $y_offset = $bottom - $fSize;
    
    $newpage = 2;
    
    $countmax = count ( $formats );
    
    $this->special_formats = array ( );
        
    for ( $count = 0; $count < $countmax; $count++ )
        {
        $format_code = $formats[$count]['key_string'];
        $format_english = $formats[$count]['description_string'];
        
        if ( isset ( $this->special_formats[$format_code] ) )
            {
            $this->special_formats[$format_code] = $format_english;
            $format_code = null;
            }
        
        if ( $format_code )
            {
            if ( $newpage )
                {
                $this->napdf_instance->AddPage();
                $this->napdf_instance->SetFont ( $fontFamily, '', $fontSize );
                $this->napdf_instance->SetFillColor ( 0 );
                $this->napdf_instance->SetTextColor ( 255 );
                $header = ""._PDF_LEGEND_HEADER."";
                if ( $newpage != 2 )
                    {
                    $header .= _PDF_CONTD;
                    }
                
                $this->napdf_instance->SetFont ( $fontFamily, 'B', $heading_height );
                $stringWidth = $this->napdf_instance->GetStringWidth ( $header );
                $cellleft = (($right + $left) / 2) - ($stringWidth / 2);
                $this->napdf_instance->Rect ( $left, $top, ($right - $left), $height, "F" );
                $this->napdf_instance->SetXY ( $cellleft, $top + 0.01 );
                $this->napdf_instance->Cell ( 0, $height, $header );
                $this->napdf_instance->SetFillColor ( 255 );
                $this->napdf_instance->SetTextColor ( 0 );
                $newpage = "";
                $this->napdf_instance->SetY ( $top + $height );
                $grayLine = 0;
                }
            else
                {
                $this->napdf_instance->SetY ( $this->napdf_instance->GetY() + 0.03 );
                }
        
            if ( $grayLine == 1 )
                {
                $this->napdf_instance->SetFillColor ( 220 );
                $grayLine = 0;
                }
            else
                {
                $this->napdf_instance->SetFillColor ( 255 );
                $grayLine = 1;
                }

            $y = $this->napdf_instance->GetY();
            
            $this->napdf_instance->Rect ( $left, $y, ($right - $left), $y_offset - (0.1 + $y), 'F' );
            
            $y += 0.02;
            
            $this->napdf_instance->SetFont ( $fontFamily, 'B', $fontSizeSmaller );
            $this->napdf_instance->SetLeftMargin ( $left );
            $this->napdf_instance->SetXY ( $left, $y );
            $this->napdf_instance->MultiCell ( $column_width, $fSize, utf8_decode ( $format_code ), 0, "L" );
    
            $this->napdf_instance->SetFont ( $fontFamily, '', $fontSizeSmaller );
            $this->napdf_instance->SetLeftMargin ( $this->right_offset );
            $this->napdf_instance->SetXY ( $this->right_offset, $y );
            $this->napdf_instance->MultiCell ( $column_width, $fSize, utf8_decode ( $format_english ), 0, "L" );
            
            if ( ($this->napdf_instance->GetY() + 0.03 + $space_needed) >= $y_offset )
                {
                $this->napdf_instance->Line ( $left, $top + height, $left, $y_offset - 0.1 );
                $this->napdf_instance->Line ( $right, $top + height, $right, $y_offset - 0.1 );
                $this->napdf_instance->SetXY ( $right, $y_offset );
                $this->napdf_instance->SetFont ( $fontFamily, 'B', $fontSize );
                $this->napdf_instance->Line ( $left, $y_offset - 0.1, $right, $y_offset - 0.1 );
                $this->napdf_instance->Cell ( 0, 0, _PDF_PAGE." ".$this->napdf_instance->PageNo(), 0, 0, "R" );
                $newpage = 1;
                }
            
            if ( $grayLine == 0 )
                {
                $this->napdf_instance->SetFillColor ( 255 );
                $this->napdf_instance->Rect ( $left, $this->napdf_instance->GetY(), ($right - $left), $y_offset - (0.1 + $this->napdf_instance->GetY()), 'F' );
                }
            }
        }
    
    if ( ($this->napdf_instance->GetY() + 0.3 + $fSize/72) > $y_offset )
        {
        $this->napdf_instance->AddPage();
        $y = $y_offset;
        }
    else
        {
        $y = $this->napdf_instance->GetY() + 0.3;
        }

    if ( !$newpage )
        {
        $this->napdf_instance->Line ( $left, $top + height, $left, $y_offset - 0.1 );
        $this->napdf_instance->Line ( $right, $top + height, $right, $y_offset - 0.1 );
        $this->napdf_instance->SetXY ( $right, $y_offset );
        $this->napdf_instance->SetFont ( $fontFamily, 'B', $fontSize );
        $this->napdf_instance->Line ( $left, $y_offset - 0.1, $right, $y_offset - 0.1 );
        $this->napdf_instance->Cell ( 0, 0, _PDF_PAGE." ".$this->napdf_instance->PageNo(), 0, 0, "R" );
        }
    
    $this->napdf_instance->SetXY ( $left, $y_offset );
    $this->napdf_instance->SetFont ( $fontFamily, 'I', $fontSize - 1 );
    $this->napdf_instance->Cell ( 0, $fSize/72, _DEFAULT_DURATION );
    }
    
    /********************************************************************
    */
    private function DrawListPage ( )
    {
    include ( dirname ( __FILE__ ).'/listprint_pdf_decls.php' );
    $meetings =& $this->napdf_instance->meeting_data;
    
    $count_max = count ( $meetings );
    
    $fontFamily = $this->napdf_instance->FontFamily;
    $fontSize = $this->napdf_instance->FontSizePt;
    
    $top = 0.125;
    $left = 0.125;
    $bottom = $this->napdf_instance->h - 0.125;
    $right = $this->napdf_instance->w - 0.125;
    $this->right_offset = $this->napdf_instance->w / 2;
    
    $heading_height = $fontSize + 2;
    $height = ($heading_height/72) + 0.02;
    $gap2 = 0.02;
    
    $fSize = $fontSize / 70;
    $fSizeSmall = ($fontSize - 1) / 70;

    $height_one_meeting = ($fSize * 3) + $gap2;
    
    $y_offset = $bottom - $fSize;
    
    $current_day = " ";
    
    $extra_height = $height + 0.05;

    $this->napdf_instance->AddPage();
    $this->pos['y'] = $top;
    $watermark_pos = 1.0;
    
    if ( $this->pos['start'] )
        {
        $this->pos['count'] = 0;
        }
    $grayLine = 0;
    while ( !$this->pos['end'] && (($this->pos['y'] + $height_one_meeting + $extra_height + ($fSizeSmall * 2)) < ($y_offset - 0.1)) )
        {
        $extra = 0;
        $contd = "";
        $meeting = $meetings[intval($this->pos['count'])];
        $this->napdf_instance->SetLeftMargin ( $left );
        
        if ( $this->pos['start'] || ($current_day != $meeting['weekday_tinyint']) )
            {
            $this->napdf_instance->SetFillColor ( 0 );
            $this->napdf_instance->SetTextColor ( 255 );
            if ( $this->pos['start'] )
                {
                $this->pos['start'] = "";
                }
            else
                {
                if ( ($this->pos['y'] == $top) && ($this->pos['weekday'] == $meeting['weekday_tinyint']) )
                    {
                    $contd = _PDF_CONTD;
                    }
                }
            
            if ( $current_day != $meeting['weekday_tinyint'] )
                {
                $this->pos['weekday'] = $meeting['weekday_tinyint'];
                $current_day = $this->pos['weekday'];
                }
            
            $header = $this->weekday_names[$current_day - 1];
            
            $header .= $contd;
            
            $this->napdf_instance->SetFont ( $fontFamily, 'B', $heading_height );
            $this->napdf_instance->Rect ( $left, $this->pos['y'], ($right - $left), $height, "F" );
            $stringWidth = $this->napdf_instance->GetStringWidth ( $header );
            $cellleft = (($right + $left) / 2) - ($stringWidth / 2);
            $this->napdf_instance->SetXY ( $cellleft, $this->pos['y'] + 0.005 );
            $this->napdf_instance->Cell ( 0, $heading_height/72, $header );
            $this->pos['y'] += ($height);
            }
        
        $this->napdf_instance->SetTextColor ( 0 );
        
        if ( $grayLine == 1 )
            {
            $this->napdf_instance->SetFillColor ( 220 );
            $grayLine = 0;
            }
        else
            {
            $this->napdf_instance->SetFillColor ( 255 );
            $grayLine = 1;
            }
        
        $this->napdf_instance->Rect ( $left, $this->pos['y'], ($right - $left), $y_offset - (0.1 + $this->pos['y']), 'F' );
        
        $cell_top = $this->pos['y'] + $gap2;
        $this->napdf_instance->SetXY ( $left, $cell_top );
        
        $this->napdf_instance->SetFont ( $fontFamily, 'B', $fontSize );
        
        $left_string = self::translate_time ( $meeting['start_time'] );
        if ( $meeting['duration_time'] && ('01:30:00' != $meeting['duration_time']) )
            {
            $left_string .= " (".self::translate_duration ( $meeting['duration_time'] ).")";
            }
            
        $left_string .= " (".$this->RearrangeFormats ( $meeting['formats'] ).")";
        
        $this->napdf_instance->SetX ( $left );
        $this->napdf_instance->MultiCell ( $this->right_offset - $left, $fSize, utf8_decode ( $left_string ), 0, "L" );
        
        $left_string = '';
        
        if ( trim ( $meeting['location_city_subsection'] ) )
            {
            $left_string .= trim ( $meeting['location_city_subsection'] );
            }
        
        if ( trim ( $meeting['location_neighborhood'] ) )
            {
            $left_string .= ' ('.trim ( $meeting['location_neighborhood'] ).')';
            }
        
        if ( $left_string )
            {
            $left_string .= ', ';
            }
        
        $left_string .= trim ( $meeting['location_municipality'] );
        
        if ( $left_string )
            {
            $left_string .= ', ';
            }
        
        $left_string .= trim ( $meeting['location_province'] );
        
        $this->napdf_instance->SetX ( $left );
        $this->napdf_instance->MultiCell ( $this->right_offset - $left, $fSize, utf8_decode ( $left_string ), 0, "L" );
        
        $desc = $this->Get_Special_Format_Text ( $meeting['formats'] );
        
        if ( trim ( $meeting['description_string'] ) )
            {
            if ( $desc )
                {
                $desc .= ", ";
                }
            $desc = trim ( $meeting['description_string'] );
            }
        
        if ( trim ( $meeting['comments'] ) )
            {
            if ( $desc )
                {
                $desc .= ", ";
                }
            $desc .= trim ( $meeting['comments'] );
            }
        
        $desc = preg_replace ( "/[\n|\r]/", ", ", $desc );
        $desc = preg_replace ( "/,\s*,/", ",", $desc );
        $desc = stripslashes ( stripslashes ( $desc ) );
        
        $trueLeft = $left;
        
        $yMax = $this->napdf_instance->GetY ( );
        
        // Done with the left side. Now for the right side.
        
        $this->napdf_instance->SetLeftMargin ( $this->right_offset );
        $this->napdf_instance->SetFont ( $fontFamily, '', $fontSize );
        $right_string = $meeting['meeting_name'];
        $this->napdf_instance->SetXY ( $this->right_offset, $cell_top );
        
        if ( trim ( $meeting['location_text'] ) )
            {
            $right_string .= " (".trim ( $meeting['location_text'] ).")";
            }

        $this->napdf_instance->MultiCell ( $right - $this->right_offset, $fSize, utf8_decode ( $right_string ), 0, "L" );
        
        $right_string = trim ( $meeting['location_street'] );

        if ( trim ( $meeting['location_info'] ) )
            {
            $right_string .= " (".trim ( $meeting['location_info'] ).")";
            }
        
        $this->napdf_instance->SetX ( $this->right_offset );
        $this->napdf_instance->MultiCell ( $right - $this->right_offset, $fSize, utf8_decode ( $right_string ), 0, "L" );
        
        $yMax = max ( $yMax, $this->napdf_instance->GetY ( ) );

        if ( $desc )
            {
            $extra = ($fSizeSmall * 3);
            $this->napdf_instance->SetFont ( $fontFamily, 'I', $fontSize - 1 );
            $this->napdf_instance->SetXY ( $left, $yMax );
            $this->napdf_instance->MultiCell ( $right - $left, $fSizeSmall, utf8_decode ( $desc ), 0, "L" );
            }
        
        $yMax = max ( $yMax, $this->napdf_instance->GetY ( ) ) + $gap2;
        $this->pos['y'] = $yMax;
        $this->pos['count']++;
        
        if ( $this->pos['count'] == $count_max )
            {
            $this->pos['end'] = 1;
            }
        else
            {
            $next_meeting = $meetings[intval($this->pos['count'])];
            
            if ( $current_day != $next_meeting['weekday_tinyint'] )
                {
                $extra_height = $height + 0.05;
                }
            else
                {
                $extra_height = 0;
                }
            }
        
        if ( $grayLine == 0 )
            {
            $this->napdf_instance->SetFillColor ( 255 );
            $this->napdf_instance->Rect ( $left, $this->pos['y'], ($right - $left), $y_offset - (0.1 + $this->pos['y']), 'F' );
            }
        }
    
    $this->napdf_instance->SetFont ( $fontFamily, 'B', $fontSize );
    $this->napdf_instance->Line ( $left, $y_offset - 0.1, $right, $y_offset - 0.1 );
    $this->napdf_instance->Line ( $left, $top + height, $left, $y_offset - 0.1 );
    $this->napdf_instance->Line ( $right, $top + height, $right, $y_offset - 0.1 );
    $this->napdf_instance->SetXY ( $right, $y_offset );
    $this->napdf_instance->Cell ( 0, 0, _PDF_PAGE." ".$this->napdf_instance->PageNo(), 0, 0, "R" );
    $this->napdf_instance->SetFont ( $fontFamily, '', $fontSize );
    }

    /********************************************************************
    */
    private function Get_Special_Format_Text ( $inFormats )
    {
    $ret = "";
    
    $format_array = split ( ",", $inFormats );

    foreach ( $format_array as $format )
        {
        if ( $this->special_formats[$format] )
            {
            if ( $ret )
                {
                $ret .= ", ";
                }
            
            $ret .= $this->special_formats[$format];
            }
        }
    
    return $ret;
    }

    /********************************************************************
    */
    private function RearrangeFormats ( $inFormats )
    {
    $inFormats = split ( ",", $inFormats );
    
    if ( !in_array ( "C", $inFormats ) && !in_array ( "O", $inFormats ) )
        {
        array_push ( $inFormats, "C" );
        }
    
    if ( !$ignore_bk && !in_array ( "BK", $inFormats ) && ((in_array ( "BT", $inFormats ) || in_array ( "IW", $inFormats ) || in_array ( "JT", $inFormats ) || in_array ( "SG", $inFormats ))) )
        {
        array_push ( $inFormats, "BK" );
        }
    
    for ( $c = 0; $c < count ( $inFormats ); $c++ )
        {
        if ( array_key_exists ( $inFormats[$c], $this->special_formats ) )
            {
            $inFormats[$c] = null;
            unset ( $inFormats[$c] );
            }
        }
    
    uasort ( $inFormats, 'listprint_napdf::sort_cmp' );
    
    $tFormats = $inFormats;
    
    $inFormats = array();
    
    foreach ( $tFormats as $format )
        {
        $format = trim ( $format );
        if ( $format )
            {
            array_push ( $inFormats, $format );
            }
        }
    
    return join ( " ", $inFormats );
    }

    /********************************************************************
    */
    private static function sort_cmp ($a, $b) 
    {
    $order_array = array(   0=>"O", 1=>"C",
                            2=>"ES", 3=>"B", 4=>"M", 5=>"W", 6=>"GL", 7=>"YP", 8=>"BK", 9=>"IP", 10=>"Pi", 11=>"RF", 12=>"Rr",
                            13=>"So", 14=>"St", 15=>"To", 16=>"Tr", 17=>"OE", 18=>"D", 19=>"SD", 20=>"TW", 21=>"IL",
                            22=>"BL", 23=>"IW", 24=>"BT", 25=>"SG", 26=>"JT",
                            27=>"Ti", 28=>"Sm", 29=>"NS", 30=>"CL", 31=>"CS", 32=>"NC", 33=>"SC", 34=>"CH", 35=>"SL", 36=>"WC" );
    
    if ( in_array ( $a, $order_array ) || in_array ( $b, $order_array ) )
        {
        return (array_search ( $a, $order_array ) < array_search ( $b, $order_array )) ? -1 : 1;
        }
    else
        {
        return 0;
        }
    }

    /********************************************************************
    */
    private static function translate_time ( $in_time_string ) 
    {
        $split = split ( ":", $in_time_string );
        if ( $in_time_string == "12:00:00" )
            {
            return "Noon";
            }
        elseif ( ($split[0] == "23") && (intval ( $split[1] ) > 45) )
            {
            return "Midnight";
            }
        else
            {
            return date ( "g:i A", strtotime ( $in_time_string ) );
            }
    }

    /********************************************************************
    */
    private static function translate_duration ( $in_time_string ) 
    {
        $t = split ( ":", $in_time_string );
        $hours = intval ( $t[0] );
        $minutes = intval ( $t[1] );
        
        $ret = '';
        
        if ( $hours )
            {
            $ret .= "$hours hour";
            
            if ( $hours > 1 )
                {
                $ret .= "s";
                }
                
            if ( $minutes )
                {
                $ret .= " and ";
                }
            }
        
        if ( $minutes )
            {
            $ret .= "$minutes minutes";
            }
        
        return $ret;
    }
    
    /**
        \brief  This is a static callback function to be used for sorting the multi-dimensional meeting_data
                array. It uses the sort_order_keys array to determine the sort.
                
        \returns an integer. -1 if a < b, 0 if a == b, or 1 if a > b.
    */
    static function sort_meeting_data_callback (&$in_a,     ///< The first meeting array to compare
                                                &$in_b      ///< The second meeting array to compare
                                                )
    {
        $ret = 0;
        
        if ( is_array ( $in_a ) && is_array ( $in_b ) && is_array ( napdf::$sort_order_keys ) )
            {
            // We reverse the array, in order to sort from least important to most important.
            $sort_keys = array_reverse ( napdf::$sort_order_keys, true );

            foreach ( $sort_keys as $key => $value )
                {
                if ( isset ( $in_a[$key] ) && isset ( $in_b[$key] ) )
                    {
                    $val_a = trim ( $in_a[$key] );
                    $val_b = trim ( $in_b[$key] );

                    if ( ('weekday_tinyint' == $key) && (napdf::$week_starts > 1) && (napdf::$week_starts < 8) )
                        {
                        $val_a -= napdf::$week_starts;

                        if ( $val_a < 0 )
                            {
                            $val_a += 8;
                            }
                        else
                            {
                            $val_a += 1;
                            }
                        
                        $val_b -= napdf::$week_starts;
                        
                        if ( $val_b < 0 )
                            {
                            $val_b += 8;
                            }
                        else
                            {
                            $val_b += 1;
                            }
                        }

                    // We know a few keys already, and we can determine how the sorting goes from there.
                    switch ( $key )
                        {
                        case 'start_time':
                        case 'duration_time':
                            $val_a = strtotime ( $val_a );
                            $val_b = strtotime ( $val_b );
                        case 'weekday_tinyint':
                        case 'id_bigint':
                        case 'shared_group_id_bigint':
                        case 'service_body_bigint':
                            $val_a = intval ( $val_a );
                            $val_b = intval ( $val_b );
                        case 'longitude':
                        case 'latitude':
                            if ( $val_a > $val_b )
                                {
                                $ret = 1;
                                }
                            elseif ( $val_b > $val_a )
                                {
                                $ret = -1;
                                }
                        break;
                        
                        default:
                            // We ignore blank values
                            if ( strlen ( $val_a ) && strlen ( $val_b ) )
                                {
                                $tmp = strcmp ( strtolower ( $val_a ), strtolower ( $val_b ) );
                                
                                if ( $tmp != 0 )
                                    {
                                    $ret = $tmp;
                                    }
                                }
                        break;
                        }
                    }
                
                if ( !$value )
                    {
                    $ret = -$ret;
                    }
                }
            }
        
        return $ret;
    }
};
?>