Forcing file download from GridFieldDetailForm

Questions
1

Hey all, I would like to generate a file download on the back of a user editing a record in a GridField and clicking a “Download SpreadSheet” button.

I have added a new GridFieldDetailForm_ItemRequest to add the extra button (which works fine), but I am unsure how to prompt a file download.

I have tried the following which appears to return the file data, but then just renders that info in the browser. Do I need to add some extra headers to the response in order to get SS to not try and render the returned data?

namespace App\Forms;

use SilverStripe\Forms\FormAction;
use SilverStripe\Control\HTTPRequest;
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
use SilverStripe\Forms\GridField\GridFieldDetailForm_ItemRequest;

class SubmissionDetailForm_ItemRequest extends GridFieldDetailForm_ItemRequest
{
    public function getFormActions()
    {
        $actions = parent::getFormActions();

        $actions->push(
            FormAction::create("doDownloadSpreadsheet", "SpreadSheet")
                ->setUseButtonTag(true)
                ->addExtraClass('btn-outline-primary btn-hide-outline')
                ->addExtraClass('font-icon-down-circled')
        );

        return $actions;
    }

    public function doDownloadSpreadsheet()
    {
        $spreadsheet = new Spreadsheet();
        $sheet = $spreadsheet->getActiveSheet();
        $sheet->setCellValue('A1', 'Hello World !');

        $writer = new Xlsx($spreadsheet);

        return HTTPRequest::send_file(
            $writer->save("php://output"),
            "file.xlsx",
            'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
        );
    }
}
2

Had to make several changes to get this working. The main issue was that I have to change the FormAction into a link to an action on the custom GridFieldDetailForm_ItemRequest. I then had to disable the Ajax on the button click.

class SubmissionDetailForm_ItemRequest extends GridFieldDetailForm_ItemRequest
{

    private static $allowed_actions = [
        "DownloadSpreadsheet"
    ];

    public function getFormActions()
    {
        $actions = parent::getFormActions();

        $classes = [
            "btn",
            "btn-outline-primary",
            "btn-hide-outline",
            "font-icon-down-circled",
            "no-ajax" // Class to disable ajax
        ];

        $sheet_button = HTML::createTag(
            "a",
            [
                'class' => implode(" ", $classes),
                'href' => $this->Link('DownloadSpreadsheet')
            ],
            "Spreadsheet"
        );

        $actions->push(
            LiteralField::create("DownloadSpreadsheet", $sheet_button)
        );

        return $actions;
    }

    public function DownloadSpreadsheet()
    {
        $spreadsheet = new Spreadsheet();
        $record = $this->getRecord();

        $sheet = $spreadsheet->getActiveSheet();
        $sheet->setCellValue('A1', 'Hello World !');

        $this->returnObjData(
            "Export-".date('d-m-Y').".xlsx",
            'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
            SpreadsheetFactory::createWriter($spreadsheet, 'Xlsx')
        );
    }

    /**
     * Generate the correct headers and output the file data to the browser
     * 
     * @param string    $filename The name of the file to output
     * @param string    $mime     The mimetype of the file
     * @param IOFactory $write    An instance of PHPOffice IO Writer
     * 
     * @return void
     */
    protected function returnObjData($filename, $mime, $writer)
    {
        // Manually return file data as PHPOffice does not appear to support streaming 
        ob_clean();

        // Redirect output to a client’s web browser (Excel2007)
        header('Content-Type: ' . $mime);
        header('Content-Disposition: attachment;filename="'.$filename.'"');
        header('Cache-Control: max-age=0');

        $writer->save('php://output');

        //terminate php
        exit;
    }
}

Next, I had to add this JS to disable AJAX (thanks to @kinglozzer on Slack for this).

(function($) {
    $.entwine('ss', function($) {
        $('#Form_ItemEditForm a.no-ajax').entwine({
            onclick: function(event) {
                var anchor = $(this);

                if(anchor.attr('target') === '_blank') {
                    window.open(anchor.attr('href'));
                } else {
                    window.location = anchor.attr('href');
                }

                return false;
            }
        });
    });
})(jQuery);

Config.yml

# Extra CSS for Admin
SilverStripe\Admin\LeftAndMain:
 extra_requirements_javascript:
   - 'app/client/dist/js/admin.js'

Thanks to everyone on the Slack group for getting this sorted

1 Like
3

Would you care creating this as a gridfield extension module? I can see it being useful for others if it can be found on GitHub, via Packagist and SS modules directory.

4

What would the module be for? Just disabling ajax support? If so, I kind of feel that some way of doing this should be in the GridField JS (maybe via a data-attribute)?