查询时的DOMX路径查询

我有以下HTML：

[...]
<div class="row clearfix">
    <div class="col1">Data</div>
    <div class="col2">Data</div>
    <div class="col3">Data</div>
    <div class="col4">Data</div>
    <div class="col5">Data</div>
    <div class="col6">Data</div>
    <div class="col7">Data</div>
    <div class="col8">Data</div>
</div><!--// row-->
<div class="row clearfix otherClass">
    <div class="col1">Data</div>
    <div class="col2">Data</div>
    <div class="col3">Data</div>
    <div class="col4">Data</div>
    <div class="col5">Data</div>
    <div class="col6">Data</div>
    <div class="col7">Data</div>
    <div class="col8">Data</div>
</div><!--// row-->
<div class="row clearfix thirdClass">
    <div class="col1">Data</div>
    <div class="col2">Data</div>
    <div class="col3">Data</div>
    <div class="col4">Data</div>
    <div class="col5">Data</div>
    <div class="col6">Data</div>
    <div class="col7">Data</div>
    <div class="col8">Data</div>
</div><!--// row-->
[...]

我想从HTML中获得所有这些div，它们都以"行clearfix"作为类开始，但可以有更多的数据。在那之后，我希望能够独立地处理每个列，所以得到col1、col2、col3等等的值。

我已经写了这个代码，但现在被卡住了。有人能帮我吗？

        $oDom = new DOMDocument();
        $oDom->loadHtml($a_sHTML);
        $oDomXpath = new DOMXpath($oDom);
        $oDomObject = $oDomXpath->query('//div[@class="row clearfix"]');
        foreach ($oDomObject as $oObject) {
            var_dump($oObject->query('//div[@class="col1"]')->nodeValue);
        }

更新*解决方案*
感谢下面的回复，我用以下代码完成了它：

    $oDom = new DOMDocument();
    @$oDom->loadHtml($a_sHTML);
    $oDomXpath = new DOMXpath($oDom);
    $oDomObject = $oDomXpath->query('//div[contains(@class,"row") and contains(@class,"clearfix")]');
    foreach ($oDomObject as $oObject) {
        foreach($oObject->childNodes as $col)
        {
            if ($col->hasAttributes())
            {
                var_dump($col->getAttribute('class') . " == " . trim($col->nodeValue));
            }
        }
    }