public function getFileRelationClassName($gridField)
    {
        $recordClass = $this->getRecordClassName($gridField);
        $hasOneFields = Config::inst()->get($recordClass, 'has_one');

        $fieldName = $this->getFileRelationName($gridField);
        if ($fieldName) {
            return $hasOneFields[$fieldName];
        } else {
            return 'SilverStripe\\Assets\\File';
        }
    }
public function getFileRelationClassName($gridField)
    {
        $recordClass = $this->getRecordClassName($gridField);
        $hasOneFields = Config::inst()->get($recordClass, 'has_one');

        $fieldName = $this->getFileRelationName($gridField);
        if ($fieldName) {
            return $hasOneFields[$fieldName];
        } else {
            return 'SilverStripe\\Assets\\File';
        }
    }
public function getFileRelationClassName ( $ gridField ) { $ recordClass = $ this -> getRecordClassName ( $ gridField ) ; $ hasOneFields = Config :: inst ( ) -> get ( $ recordClass , 'has_one' ) ; $ fieldName = $ this -> getFileRelationName ( $ gridField ) ; if ( $ fieldName ) { return $ hasOneFields [ $ fieldName ] ; } else { return 'SilverStripe\\Assets\\File' ; } }
Return the ClassName of the fileRelation
i.e. 'MyImage' => 'Image' will return 'Image'
i.e. 'MyImage' => 'File' will return 'File'.

@param  GridField $gridField
@return string file relation className
Return the ClassName of the fileRelation i . e . MyImage = > Image will return Image i . e . MyImage = > File will return File .