Multicolumn for the page module

i've found a temporary fix for this problem.

@Extension-Developer: please review and merge this into the extension.

File: multicolumn/lib/class.tx_multicolumn_db.php
Function: public static function getContentElementsFromContainer

Line: 73
Change: if(!$isWorkspace) $whereClause .= self::enableFields($fromTable, $showHidden);
To: $whereClause .= self::enableFields($fromTable, $showHidden);

Line: 83
After: array_pop($output);
Add: if ($GLOBALS['TSFE']->sys_page->versioningPreview) foreach ($output AS &$row) t3lib_BEfunc::workspaceOL("tt_content",$row);

Thank you!

Problem is still or again there with multicolumn 2.1.13 and TYPO3 v4.7.1

I see function getWorkspaceClause in file class.tx_multicolumn_db.php,
but there doesn't seem to be any t3lib_BEfunc::workspaceOL() in there.

Confirmed. The Problem is there in 2.1.13.
It isn't easy to fix because if you use workspaces the "where"-clause in the select can only be "pid >= 0" or "pid = ".$someNumber
So i made 2 seperate queries... if someone knows a better way that does it, write it down here :)
EDIT: seems that i had a little bug in my fix... corrected that and raised the performance, from the FE there will be only 1 DB Select.

File: multicolumn/lib/class.tx_multicolumn_db.php
Function: public static function getContentElementsFromContainer
Change: the whole method
To:

  public static function getContentElementsFromContainer($colPos = null, $pid = null, $mulitColumnParentId, $sysLanguageUid = 0, $showHidden = false, $additionalWhere = null, tx_cms_layout &$cmsLayout = null) {
    $selectFields = '*';
        $fromTable = 'tt_content';
        $whereClause = '';
    if($pid)
      $whereClause .= 'pid = ' . intval($pid);
    else
      $whereClause .= $additionalWhere; 
        $orderBy = 'sorting ASC';

    $res = $GLOBALS['TYPO3_DB']->exec_SELECTquery($selectFields, $fromTable, $whereClause, null, $orderBy);

    $whereClause = null;
    while($row = $GLOBALS['TYPO3_DB']->sql_fetch_assoc($res)) {
      switch(TYPO3_MODE) {
        case 'FE':
          $GLOBALS['TSFE']->sys_page->versionOL($fromTable, $row);
          break;
        case 'BE':
          t3lib_BEfunc::workspaceOL($fromTable, $row);
          break;

      }

      if (is_array($row)
          && $row['deleted'] == 0
          && $row['tx_multicolumn_parentid'] == intval($mulitColumnParentId)
          && (!$colPos || $colPos && $row['colPos'] == intval($colPos))
          && $row['sys_language_uid'] == intval($sysLanguageUid)) {

        if (!$whereClause)
          $whereClause = 'uid = '.$row['uid'];
        else
          $whereClause .= ' || uid = '.$row['uid'];

        $output[] = $row;
      }
    }

    if ($cmsLayout && $whereClause) {
      $res = $GLOBALS['TYPO3_DB']->exec_SELECTquery($selectFields, $fromTable, $whereClause, null, $orderBy);

      if (!$GLOBALS['TYPO3_DB']->sql_error()) {
        //use cms layout object for correct icons
        $output = $cmsLayout->getResult($res,'tt_content');

        $GLOBALS['TYPO3_DB']->sql_free_result($res);
      }
    }

    return $output;
  }

When using the solution of Robert Becker you can not hide nested Content Elements any more. They are shown in frontend anyway, whether they are hidden or not.

There is one line missing. After the row

&& $row['deleted']  0

you just have to add

&& $row['hidden']  0

to check, if an element is hidden or not.