classe per datagrid inserimento di una query dentro un array

[rocco.mod]

salve a tutti , ho cambiato modo di passare i dati all datagrid , mentre prima li passavo con un altra classe , adesso li passo con la stessa classe cosi

    $sortable->displayGrid("UserId", "ID");
    $sortable->displayGrid("Name", "Name");
    $sortable->displayGrid("Email", "Email");
    $sortable->displayGrid("DOB", "DOB");
    $sortable->displayGrid("ru_fp", "ru_fp"); 

e riceve i dati cosi :

    function displayGrid($name, $title) {
    
        $this->name[] = $name;
        $this->title[] = $title;
        $this->columContent = array($this->name , $this->title);
    } 

però , mi stampa un errore

Warning: Invalid argument supplied for foreach() in C:\Programmi\Apache Software Foundation\Apache2.2\htdocs\phpsorttable\php_sort_table.

questo e il foreach dell errore :

        foreach($this->columContent as $column)
        {    
            $sortLink = $this->selfLink . 'rows=' .$this->rows.'&offset='.$this->offset;
            $sortLink .= '&sortby='.$column->name;
            $sortLink .= ($this->sortdir == 'ASC') ? '&sortdir=DESC' : '&sortdir=ASC';
            
            echo '<td id="headerCell"'; 
                if(!empty($this->columContent[$index]['class']))    echo 'class   = "'.$this->columContent[$index]['class'].'"';   
                if(!empty($this->columContent[$index]['width']))    echo 'width   = "'.$this->columContent[$index]['width'].'"';    
                if(!empty($this->columContent[$index]['height']))   echo 'height  = "'.$this->columContent[$index]['height'].'"';   
                if(!empty($this->columContent[$index]['colspan']))  echo 'colspan = "'.$this->columContent[$index]['colspan'].'"';   
                if(!empty($this->columContent[$index]['align']))    echo 'align   = "'.$this->columContent[$index]['align'].'"';   
                if(!empty($this->columContent[$index]['valign']))   echo 'valign  = "'.$this->columContent[$index]['valign'].'"';   
             echo 'nowrap="nowrap">';
                               
                echo '[url='. $sortLink . ']'.$column->title .'[/url]';
            if($this->sortby == $column->name)
                echo '[img]'.$this->imgFilePath . $this->sortimg .'[/img]';
                
                
            echo '</td>';
        } 

perche ? cosa sto sbagliando ? grazie