Magento从后台读取数据，转换成数组，去掉空元素的过程

$whiteLists=trim(Mage::getStoreConfig('guestpermissions/white_list/cms_pages'));  //从后台的textarea获取字符串

$whiteLists=explode("\n", str_replace("\n\n", "\n", str_replace("\r", "\n", $whiteLists)));  //分割数组

foreach($whiteLists as $key=>$item){   将空的元素去掉，如：a[] = {'','a','','','b'}  变成 a[] = {'a','b'}
   if(empty($item)){
         unset($whiteLists[$key]);
    }
}