导出CSV或PDF基于datatable Laravel 4

我有一个数据表，其中包含从数据库检索的数据。当我在搜索文本框(搜索文本框是由数据表生成的)中输入一些关键字时，表的结果会发生变化。这很好。但是当我点击导出到csv或pdf时，csv或pdf的结果将从数据库而不是数据表中检索。

如何导出到csv/pdf基于数据表插件使用laravel?

<link href="plugins/datatables/dataTables.bootstrap.css" rel="stylesheet" type="text/css" />
<script src="plugins/datatables/jquery.dataTables.min.js" type="text/javascript"></script>
<script src="plugins/datatables/dataTables.bootstrap.min.js" type="text/javascript"></script>

//

public function sales_csv(){    
    // columns      
    $arrSelectFields = array(
        -- columns --
    );
    // query
    -- sql queries --
    // passing the columns which I want from the result set. Useful when we have not selected required fields
    $arrColumns = $arrSelectFields;
    // define the first row which will come as the first row in the csv
    $arrFirstRow = $arrSelectFields;
    // building the options array
    $options = array(
        'columns' => $arrColumns,
        'firstRow' => $arrFirstRow,
    );
    // creating the Files object from the Utility package.
    $Files = new Files;
    return $Files->convertToReportsSalesCSV($query, $options);
}