WB 2.08.x

<?php

// $Id: include.php 827 2008-04-14 18:54:58Z doc $

/*

    show_menu2: show_menu replacement for Website Baker 

    Copyright (C) 2006-2008, Brodie Thiesfield

    This program is free software; you can redistribute it and/or

    modify it under the terms of the GNU General Public License

    as published by the Free Software Foundation; either version 2

    of the License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with this program; if not, write to the Free Software

    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  

    02110-1301, USA.

    ***********************************************

    ** Version 4.5: see README for documentation **

    ***********************************************

*/

define('SM2_ROOT',       -1000);

define('SM2_CURR',       -2000);

define('SM2_ALLMENU',       -1);

define('SM2_START',       1000);

define('SM2_MAX',         2000);

define('SM2_ALL',       0x0001); // bit 0 (group 1) (Note: also used for max level!)

define('SM2_TRIM',      0x0002); // bit 1 (group 1)

define('SM2_CRUMB',     0x0004); // bit 2 (group 1)

define('SM2_SIBLING',   0x0008); // bit 3 (group 1)

define('SM2_NUMCLASS',  0x0010); // bit 4

define('SM2_ALLINFO',   0x0020); // bit 5

define('SM2_NOCACHE',   0x0040); // bit 6

define('SM2_PRETTY',    0x0080); // bit 7

define('SM2_ESCAPE',    0x0100); // bit 8

define('SM2_NOESCAPE',       0); // NOOP, unnecessary with WB 2.6.7+

define('SM2_BUFFER',    0x0200); // bit 9

define('SM2_CURRTREE',  0x0400); // bit 10

define('_SM2_GROUP_1',  0x000F); // exactly one flag from group 1 is required

// Implement support for page_menu and show_menu using show_menu2. If you remove

// the comments characters from the beginning of the following include, all menu

// functions in Website Baker will be implemented using show_menu2. While it is

// commented out, the original WB functions will be used.

//include('legacy.php');

// This class is the default menu formatter for sm2. If desired, you can 

// create your own formatter class and pass the object into show_menu2 

// as $aItemFormat.

define('SM2_CONDITIONAL','if\s*\(([^\)]+)\)\s*{([^}]*)}\s*(?:else\s*{([^}]*)}\s*)?');

define('SM2_COND_TERM','\s*(\w+)\s*(<|<=|==|=|=>|>|!=)\s*([\w\-]+)\s*');

class SM2_Formatter

{

    var $output;

    var $flags;

    var $itemOpen;

    var $itemClose;

    var $menuOpen;

    var $menuClose;

    var $topItemOpen;

    var $topMenuOpen;

    var $isFirst;

    var $page;

    var $url;

    var $currSib;

    var $sibCount;

    var $currClass;

    var $prettyLevel;

    // output the data

    function output($aString) {

        if ($this->flags & SM2_BUFFER) {

            $this->output .= $aString;

        }

        else {

            echo $aString;

        }

    }

    // set the default values for all of our formatting items

    function set($aFlags, $aItemOpen, $aItemClose, $aMenuOpen, $aMenuClose, $aTopItemOpen, $aTopMenuOpen) {

        $this->flags        = $aFlags;

        $this->itemOpen     = is_string($aItemOpen)    ? $aItemOpen    : '[li][a][menu_title]</a>';

        $this->itemClose    = is_string($aItemClose)   ? $aItemClose   : '</li>';

        $this->menuOpen     = is_string($aMenuOpen)    ? $aMenuOpen    : '[ul]';

        $this->menuClose    = is_string($aMenuClose)   ? $aMenuClose   : '</ul>';

        $this->topItemOpen  = is_string($aTopItemOpen) ? $aTopItemOpen : $this->itemOpen;

        $this->topMenuOpen  = is_string($aTopMenuOpen) ? $aTopMenuOpen : $this->menuOpen;

    }

    // initialize the state of the formatter before anything is output

    function initialize() {

        $this->output = '';

        $this->prettyLevel = 0;

        if ($this->flags & SM2_PRETTY) {

            $this->output("\n<!-- show_menu2 -->");

        }

    }

    // start a menu     

    function startList(&$aPage, &$aUrl) {

        $currClass = '';

        $currItem = $this->menuOpen;

        // use the top level menu open if this is the first menu

        if ($this->topMenuOpen) {

            $currItem = $this->topMenuOpen;

            $currClass .= ' menu-top';

            $this->topMenuOpen = false;

        }

        // add the numbered menu class only if requested

        if (($this->flags & SM2_NUMCLASS) == SM2_NUMCLASS) {

            $currClass .= ' menu-'.$aPage['level'];

        }

        $this->prettyLevel += 1;

        // replace all keywords in the output

        if ($this->flags & SM2_PRETTY) {

            $this->output("\n".str_repeat(' ',$this->prettyLevel).

                $this->format($aPage, $aUrl, $currItem, $currClass));

        }

        else {

            $this->output($this->format($aPage, $aUrl, $currItem, $currClass));

        }

        $this->prettyLevel += 3;

    }

    // start an item within the menu

    function startItem(&$aPage, &$aUrl, $aCurrSib, $aSibCount) {

        // generate our class list

        $currClass = '';

        if (($this->flags & SM2_NUMCLASS) == SM2_NUMCLASS) {

            $currClass .= ' menu-'.$aPage['level'];

        }

        if (array_key_exists('sm2_has_child', $aPage)) {

            // not set if false, so existence = true

            $currClass .= ' menu-expand';

        }

        if ($aPage['page_id'] == PAGE_ID) {

            $currClass .= ' menu-current';

        }

        elseif (array_key_exists('sm2_is_parent', $aPage)) { 

            // not set if false, so existence = true

            $currClass .= ' menu-parent';

        }

        elseif (array_key_exists('sm2_is_sibling', $aPage)) {

            // not set if false, so existence = true

            $currClass .= ' menu-sibling';

        }

        elseif (array_key_exists('sm2_child_level',$aPage)) {

            // not set if not a child

            $currClass .= ' menu-child';

            if (($this->flags & SM2_NUMCLASS) == SM2_NUMCLASS) {

                $currClass .= ' menu-child-'.($aPage['sm2_child_level']-1);

            }

        }

        if ($aCurrSib == 1) {

            $currClass .= ' menu-first';

        }

        if ($aCurrSib == $aSibCount) {

            $currClass .= ' menu-last';

        }

        // use the top level item if this is the first item

        $currItem = $this->itemOpen;

        if ($this->topItemOpen) {

            $currItem = $this->topItemOpen;

            $this->topItemOpen = false;

        }

        // replace all keywords in the output

        if ($this->flags & SM2_PRETTY) {

            $this->output("\n".str_repeat(' ',$this->prettyLevel));

        }

        $this->output($this->format($aPage, $aUrl, $currItem, $currClass, $aCurrSib, $aSibCount));

    }

    // find and replace all keywords, setting the state variables first

    function format(&$aPage, &$aUrl, &$aCurrItem, &$aCurrClass, 

        $aCurrSib = 0, $aSibCount = 0) 

    {

        $this->page      = &$aPage;

        $this->url       = &$aUrl;

        $this->currClass = trim($aCurrClass);

        $this->currSib   = $aCurrSib;

        $this->sibCount  = $aSibCount;

        $item = $this->format2($aCurrItem);

        unset($this->page);

        unset($this->url);

        unset($this->currClass);

        return $item;

    }

    // find and replace all keywords

    function format2(&$aCurrItem) {

        if (!is_string($aCurrItem)) return '';

        return preg_replace(

            '@\[('.

                'a|ac|/a|li|/li|ul|/ul|menu_title|page_title|url|target|page_id|'.

                'parent|level|sib|sibCount|class|description|keywords|'.

                SM2_CONDITIONAL.

            ')\]@e', 

            '$this->replace("\1")', $aCurrItem);

    }

    // replace the keywords

    function replace($aMatch) {

        switch ($aMatch) {

        case 'a':

            return '<a href="'.$this->url.'" target="'.$this->page['target'].'">';

        case 'ac':

            return '<a href="'.$this->url.'" target="'.$this->page['target'].'" class="'.$this->currClass.'">';

        case '/a':

            return '</a>';

        case 'li':

            return '<li class="'.$this->currClass.'">';

        case '/li':

            return '</li>';

        case 'ul':

            return '<ul class="'.$this->currClass.'">';

        case '/ul':

            return '</ul>';

        case 'url':

            return $this->url;

        case 'sib':

            return $this->currSib;

        case 'sibCount':

            return $this->sibCount;

        case 'class':

            return $this->currClass;

        default:

            if (array_key_exists($aMatch, $this->page)) {

                if ($this->flags & SM2_ESCAPE) {

                    return htmlspecialchars($this->page[$aMatch], ENT_QUOTES);

                }

                else {

                    return $this->page[$aMatch];

                }

            }

            if (preg_match('/'.SM2_CONDITIONAL.'/', $aMatch, $rgMatches)) {

                return $this->replaceIf($rgMatches[1], $rgMatches[2], $rgMatches[3]);

            }

        }

        return "[$aMatch=UNKNOWN]";

    }

    // conditional replacement

    function replaceIf(&$aExpression, &$aIfValue, &$aElseValue) {

        // evaluate all of the tests in the conditional (we don't do short-circuit

        // evaluation) and replace the string test with the boolean result

        $rgTests = preg_split('/(\|\||\&\&)/', $aExpression, -1, PREG_SPLIT_DELIM_CAPTURE);

        for ($n = 0; $n < count($rgTests); $n += 2) {

            if (preg_match('/'.SM2_COND_TERM.'/', $rgTests[$n], $rgMatches)) {

                $rgTests[$n] = $this->ifTest($rgMatches[1], $rgMatches[2], $rgMatches[3]);

            }

            else {

                error_log("show_menu2 error: conditional expression is invalid!");

                $rgTests[$n] = false;

            }

        }

        // combine all test results for a final result

        $ok = $rgTests[0];

        for ($n = 1; $n+1 < count($rgTests); $n += 2) {

            if ($rgTests[$n] == '||') {

                $ok = $ok || $rgTests[$n+1];

            }

            else {

                $ok = $ok && $rgTests[$n+1];

            }

        }

        // return the formatted expression if the test succeeded

        return $ok ? $this->format2($aIfValue) : $this->format2($aElseValue);

    }

    // conditional test

    function ifTest(&$aKey, &$aOperator, &$aValue) {

        global $wb;

        // find the correct operand

        $operand = false;

        switch($aKey) {

        case 'class':

            // we need to wrap the class names in spaces so we can test for a unique

            // class name that will not match prefixes or suffixes. Same must be done

            // for the value we are testing.

            $operand = " $this->currClass "; 

            break;

        case 'sib':

            $operand = $this->currSib;

            if ($aValue == 'sibCount') {

                $aValue = $this->sibCount;

            }

            break;

        case 'sibCount':

            $operand = $this->sibCount;

            break;

        case 'level':

            $operand = $this->page['level'];

            switch ($aValue) {

            case 'root':    $aValue = 0; break;

            case 'granny':  $aValue = $wb->page['level']-2; break;

            case 'parent':  $aValue = $wb->page['level']-1; break;

            case 'current': $aValue = $wb->page['level'];   break;

            case 'child':   $aValue = $wb->page['level']+1; break;

            }

            if ($aValue < 0) $aValue = 0;

            break;

        case 'id':

            $operand = $this->page['page_id'];

            switch ($aValue) {

            case 'parent':  $aValue = $wb->page['parent'];  break;

            case 'current': $aValue = $wb->page['page_id']; break;

            }

            break;

        default:

            return '';

        }

        // do the test        

        $ok = false;

        switch ($aOperator) { 

        case '<':

            $ok = ($operand < $aValue); 

            break;

        case '<=':

            $ok = ($operand <= $aValue); 

            break;

        case '=':

        case '==':

        case '!=':

            if ($aKey == 'class') {

                $ok = strstr($operand, " $aValue ") !== FALSE;

            }

            else {

                $ok = ($operand == $aValue); 

            }

            if ($aOperator == '!=') {

                $ok = !$ok;

            }

            break;

        case '>=':

            $ok = ($operand >= $aValue); 

        case '>':

            $ok = ($operand > $aValue); 

        }

        return $ok;

    }

    // finish the current menu item

    function finishItem() {

        if ($this->flags & SM2_PRETTY) {

            $this->output(str_repeat(' ',$this->prettyLevel).$this->itemClose);

        }

        else {

            $this->output($this->itemClose);

        }

    }

    // finish the current menu

    function finishList() {

        $this->prettyLevel -= 3;

        if ($this->flags & SM2_PRETTY) {

            $this->output("\n".str_repeat(' ',$this->prettyLevel).$this->menuClose."\n");

        }

        else {

            $this->output($this->menuClose);

        }

        $this->prettyLevel -= 1;

    }

    // cleanup the state of the formatter after everything has been output

    function finalize() {

        if ($this->flags & SM2_PRETTY) {

            $this->output("\n");

        }

    }

    // return the output

    function getOutput() {

        return $this->output;

    }

};

function show_menu2(

    $aMenu          = 0,

    $aStart         = SM2_ROOT,

    $aMaxLevel      = -1999, // SM2_CURR+1

    $aFlags         = SM2_TRIM,

    $aItemOpen      = false,

    $aItemClose     = false,

    $aMenuOpen      = false,

    $aMenuClose     = false,

    $aTopItemOpen   = false,

    $aTopMenuOpen   = false

    )

{

    global $wb;

    // ensure we have our group 1 flag, we don't check for the "exactly 1" part, but 

    // we do ensure that they provide at least one.

    if (0 == ($aFlags & _SM2_GROUP_1)) {

        error_log("show_menu2 error: no flags from group 1 supplied! Exactly one flag is required!");

        $aFlags |= SM2_TRIM; // default to TRIM

    }

    // fix up the menu number to default to the menu number

    // of the current page if no menu has been supplied

    if ($aMenu == 0) {

        $aMenu = $wb->page['menu'] == '' ? 1 : $wb->page['menu'];

    } 

    // Set some of the $wb->page[] settings to defaults if not set

    $pageLevel = $wb->page['level'] == '' ? 0 : $wb->page['level'];

    $pageParent = $wb->page['parent'] == '' ? 0 : $wb->page['parent'];

    // adjust the start level and start page ID as necessary to

    // handle the special values that can be passed in as $aStart

    $aStartLevel = 0;

    if ($aStart < SM2_ROOT) {   // SM2_CURR+N

        if ($aStart == SM2_CURR) {

            $aStartLevel = $pageLevel;

            $aStart =  $pageParent;

        }

        else {

            $aStartLevel = $pageLevel + $aStart - SM2_CURR;

            $aStart = PAGE_ID; 

        }

    }

    elseif ($aStart < 0) {   // SM2_ROOT+N

        $aStartLevel = $aStart - SM2_ROOT;

        $aStart = 0;

    }

    // we get the menu data once and store it in a global variable. This allows 

    // multiple calls to show_menu2 in a single page with only a single call to 

    // the database. If this variable exists, then we have already retrieved all

    // of the information and processed it, so we don't need to do it again.

    if (($aFlags & SM2_NOCACHE) != 0

        || !array_key_exists('show_menu2_data', $GLOBALS) 

        || !array_key_exists($aMenu, $GLOBALS['show_menu2_data'])) 

    {

        global $database;

        // create an array of all parents of the current page. As the page_trail

        // doesn't include the theoretical root element 0, we add it ourselves.

        $rgCurrParents = split(',', '0,'.$wb->page['page_trail']);

        array_pop($rgCurrParents); // remove the current page

        $rgParent = array();

        // if the caller wants all menus gathered together (e.g. for a sitemap)

        // then we don't limit our SQL query

        $menuLimitSql = ' AND menu = ' .$aMenu;

        if ($aMenu == SM2_ALLMENU) {

            $menuLimitSql = '';

        }

        // we only load the description and keywords if we have been told to,

        // this cuts the memory load for pages that don't use them. Note that if

        // we haven't been told to load these fields the *FIRST TIME* show_menu2

        // is called (i.e. where the database is loaded) then the info won't

        // exist anyhow.

        $fields = 'parent,page_id,menu_title,page_title,link,target,level,visibility,viewing_groups';

        if(version_compare(WB_VERSION, '2.7', '>=')) { // WB 2.7+

            $fields .= ',viewing_users';

        }

        if ($aFlags & SM2_ALLINFO) {

            $fields = '*';

        }

        // get this once for performance. We really should be calling only need to

        // call $wb->get_group_id() but that outputs a warning notice if the 

        // groupid isn't set in the session, so we check it first here.

        $currGroup = array_key_exists('GROUP_ID', $_SESSION) ? 

            ','.$wb->get_group_id().',' : 'NOGROUP';

        // we request all matching rows from the database for the menu that we 

        // are about to create it is cheaper for us to get everything we need 

        // from the database once and create the menu from memory then make 

        // multiple calls to the database. 

        $sql = "SELECT $fields FROM ".TABLE_PREFIX.

               "pages WHERE $wb->extra_where_sql $menuLimitSql ".

               'ORDER BY level ASC, position ASC';

        $oRowset = $database->query($sql);

        if (is_object($oRowset) && $oRowset->numRows() > 0) {

            // create an in memory array of the database data based on the item's parent. 

            // The array stores all elements in the correct display order.

            while ($page = $oRowset->fetchRow()) {

				// ignore all pages that the current user is not permitted to view

                if(version_compare(WB_VERSION, '2.7', '>=')) { // WB >= 2.7

                    // 1. all pages with no active sections (unless it is the top page) are ignored

                    if(!$wb->page_is_active($page) && $page['link'] != $wb->default_link && !INTRO_PAGE) {

                      continue; 

                    }

                    // 2. all pages not visible to this user (unless always visible to registered users) are ignored

                    if(!$wb->page_is_visible($page) && $page['visibility'] != 'registered') {

                        continue;

                    }

                }

                else {  // WB < 2.7

                    // We can't do this in SQL as the viewing_groups column contains multiple 

                    // values which are hard to process correctly in SQL. Essentially we add the

                    // following limit to the SQL query above:

                    //  (visibility <> "private" OR $wb->get_group_id() IN viewing_groups)

                    if ($page['visibility'] == 'private' 

                        && false === strstr(",{$page['viewing_groups']},", $currGroup)) 

                    {

                        continue;

                    }

                }

                // ensure that we have an array entry in the table to add this to

                $idx = $page['parent'];

                if (!array_key_exists($idx, $rgParent)) {

                    $rgParent[$idx] = array();

                }

                // mark our current page as being on the current path

                if ($page['page_id'] == PAGE_ID) {

                    $page['sm2_on_curr_path'] = true;

                }

                // mark parents of the current page as such

                if (in_array($page['page_id'], $rgCurrParents)) {

                    $page['sm2_is_parent'] = true;

                    $page['sm2_on_curr_path'] = true;

                }

                // add the entry to the array                

                $rgParent[$idx][] = $page;

            }

        }    

        unset($oRowset);

        // mark all elements that are siblings of any element on the current path

        foreach ($rgCurrParents as $x) {

            if (array_key_exists($x, $rgParent)) {

                foreach (array_keys($rgParent[$x]) as $y) {

                    $mark =& $rgParent[$x][$y];

                    $mark['sm2_path_sibling'] = true;

                    unset($mark);

                }

            }

        }

        // mark all elements that have children and are siblings of the current page

        $parentId = $pageParent;

        foreach (array_keys($rgParent) as $x) {

            $childSet =& $rgParent[$x];

            foreach (array_keys($childSet) as $y) {

                $mark =& $childSet[$y];

                if (array_key_exists($mark['page_id'], $rgParent)) {

                    $mark['sm2_has_child'] = true;

                }

                if ($mark['parent'] == $parentId && $mark['page_id'] != PAGE_ID) {

                    $mark['sm2_is_sibling'] = true;

                }

                unset($mark);

            }

            unset($childSet);

        }

        // mark all children of the current page. We don't do this when 

        // PAGE_ID is 0, as 0 is the parent of everything. PAGE_ID == 0 

        // occurs on special pages like search results.

        if (PAGE_ID != 0) {

            sm2_mark_children($rgParent, PAGE_ID, 1);

        }

        // store the complete processed menu data as a global. We don't 

        // need to read this from the database anymore regardless of how 

        // many menus are displayed on the same page.

        if (!array_key_exists('show_menu2_data', $GLOBALS)) {

            $GLOBALS['show_menu2_data'] = array();

        }

        $GLOBALS['show_menu2_data'][$aMenu] =& $rgParent;

        unset($rgParent);

    }

    // adjust $aMaxLevel to the level number of the final level that 

    // will be displayed. That is, we display all levels <= aMaxLevel.

    if ($aMaxLevel == SM2_ALL) {

        $aMaxLevel = 1000;

    }

    elseif ($aMaxLevel < 0) {   // SM2_CURR+N

        $aMaxLevel += $pageLevel - SM2_CURR;

    }

    elseif ($aMaxLevel >= SM2_MAX) { // SM2_MAX+N

        $aMaxLevel += $aStartLevel - SM2_MAX;

        if ($aMaxLevel > $pageLevel) {

            $aMaxLevel = $pageLevel;

        }

    }

    else {  // SM2_START+N

        $aMaxLevel += $aStartLevel - SM2_START;

    }

    // generate the menu

    $retval = false;

    if (array_key_exists($aStart, $GLOBALS['show_menu2_data'][$aMenu])) {

        $formatter = $aItemOpen;

        if (!is_object($aItemOpen)) {

            static $sm2formatter;

            if (!isset($sm2formatter)) {

                $sm2formatter = new SM2_Formatter;

            }

            $formatter = $sm2formatter;

            $formatter->set($aFlags, $aItemOpen, $aItemClose, 

                $aMenuOpen, $aMenuClose, $aTopItemOpen, $aTopMenuOpen);

        }

        // display the menu

        $formatter->initialize();

        sm2_recurse(

            $GLOBALS['show_menu2_data'][$aMenu],

            $aStart,    // parent id to start displaying sub-menus

            $aStartLevel, $aMaxLevel, $aFlags, 

            $formatter);

        $formatter->finalize();

        // if we are returning something, get the data

        if (($aFlags & SM2_BUFFER) != 0) {

            $retval = $formatter->getOutput();

        }

    }

    // clear the data if we aren't caching it

    if (($aFlags & SM2_NOCACHE) != 0) {

        unset($GLOBALS['show_menu2_data'][$aMenu]);

    }

    return $retval;

}

function sm2_mark_children(&$rgParent, $aStart, $aChildLevel)

{

    if (array_key_exists($aStart, $rgParent)) {

        foreach (array_keys($rgParent[$aStart]) as $y) {

            $mark =& $rgParent[$aStart][$y];

            $mark['sm2_child_level'] = $aChildLevel;

            $mark['sm2_on_curr_path'] = true;

            sm2_mark_children($rgParent, $mark['page_id'], $aChildLevel+1);

        }

    }

}

function sm2_recurse(

    &$rgParent, $aStart, 

    $aStartLevel, $aMaxLevel, $aFlags, 

    &$aFormatter

    )

{

    global $wb;

    // on entry to this function we know that there are entries for this 

    // parent and all entries for that parent are being displayed. We also 

    // need to check if any of the children need to be displayed too.

    $isListOpen = false;

    $currentLevel = $wb->page['level'] == '' ? 0 : $wb->page['level'];

    // get the number of siblings so we can check pass this and check if the 

    // item is first or last

    $sibCount = count($rgParent[$aStart]);

    $currSib = 0;

    foreach ($rgParent[$aStart] as $page) {

        $currSib++;

        // skip any elements that are lower than the maximum level

        $pageLevel = $page['level'];

        if ($pageLevel > $aMaxLevel) {

            continue;

        }

        // this affects ONLY the top level

        if ($aStart == 0 && ($aFlags & SM2_CURRTREE)) {

            if (!array_key_exists('sm2_on_curr_path', $page)) { // not set if false, so existence = true

                continue;

            }

            $sibCount = 1;

        }

        // trim the tree as appropriate

        if ($aFlags & SM2_SIBLING) {

            // parents, and siblings and children of current only

            if (!array_key_exists('sm2_on_curr_path', $page)      // not set if false, so existence = true

                && !array_key_exists('sm2_is_sibling', $page)     // not set if false, so existence = true

                && !array_key_exists('sm2_child_level', $page)) { // not set if false, so existence = true

                continue;

            }

        }

        else if ($aFlags & SM2_TRIM) {

            // parents and siblings of parents

            if (!array_key_exists('sm2_on_curr_path', $page)    // not set if false, so existence = true

                && !array_key_exists('sm2_path_sibling', $page)) {  // not set if false, so existence = true

                continue;

            }

        }

        elseif ($aFlags & SM2_CRUMB) {

            // parents only

            if (!array_key_exists('sm2_on_curr_path', $page)    // not set if false, so existence = true

                || array_key_exists('sm2_child_level', $page)) {  // not set if false, so existence = true

                continue;

            }

        }

        // depth first traverse

        $nextParent = $page['page_id'];

        // display the current element if we have reached the start level

        if ($pageLevel >= $aStartLevel) {

            // massage the link into the correct form

            if(!INTRO_PAGE && $page['link'] == $wb->default_link) {

                $url = WB_URL;

            }

            else {

                $url = $wb->page_link($page['link']);

            }

            // we open the list only when we absolutely need to

            if (!$isListOpen) {

                $aFormatter->startList($page, $url);

                $isListOpen = true;

            }

            $aFormatter->startItem($page, $url, $currSib, $sibCount);

        }

        // display children as appropriate

        if ($pageLevel + 1 <= $aMaxLevel 

            && array_key_exists('sm2_has_child', $page)) {  // not set if false, so existence = true

            sm2_recurse(

                $rgParent, $nextParent, // parent id to start displaying sub-menus

                $aStartLevel, $aMaxLevel, $aFlags, 

                $aFormatter);

        }

        // close the current element if appropriate

        if ($pageLevel >= $aStartLevel) {

            $aFormatter->finishItem($pageLevel, $page);

        }

    }

    // close the list if we opened one

    if ($isListOpen) {

        $aFormatter->finishList();

    }

}

?>