I try export data from database to .csv. When I click export link I don't see save window in browser for a very long time if there is quite a lot amount of data. It can be quite confusing if the script looks like hanging for some time and after quite a long time one can see save window in browser. The code is something like this in controller:
$this->_helper->layout->disableLayout();
$this->_helper->viewRenderer->setNoRender();
$fileName = $list->list_name . '.csv';
$this->getResponse()->setHeader('Content-Type', 'text/csv; charset=utf-8')
->setHeader('Content-Disposition', 'attachment; filename="'. $fileName . '"');
$contacts = new Contact();
$contacts->export($listId);
Export method reads records one by one and prints it something like this:
$fp = fopen('php://output', 'w');
foreach ($mongodbCursor as $subscriber) {
$row = formRow($subscriber);
fputcsv($fp, $row);
}
I see on some applications that save winow appear almost immediately and when you click save you see progress of downloading.
I tried to replace:
$this->getResponse()->setHeader('Content-Type', 'text/csv; charset=utf-8')
->setHeader('Content-Disposition', 'attachment; filename="'. $fileName . '"');
with this one:
header('Content-Type: text/csv; charset=utf-8');
header('Content-Disposition: attachment; filename="'. $fileName . '"');
It didn't help so far. I wonder if it's possible to send headers before all data are read one by one from database? Thank your for your assistance.
Hmm I'm not familiar with php://output, my application writes my information with fopen,fwrite,fclose to a temporary file afterwards I give it out with similiar header(); options.
$filesize = filesize("tmp/export.csv");
header("Content-Type: text/csv");
header("Content-Disposition: attachment; filename=\"export.csv\"");
header("Conent-Length: $filesize");
readfile("tmp/export.csv");
unlink("tmp/export.csv");
exit;
This one gives the download window of your browser instantly.
You could try to do this:
$this->getResponse()->setHeader() (the response content might be saved in a buffer and outputed only when it is completed - the time the export finishes)EDIT
Replace fputcsv with a function like print_row below
function print_row($row) {
echo '"' . implode('","', $row) . '"' . "
";
}
The function gets the first parameter as an array, adds " and , and echoes to content.
// $file = path of file
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename($file));
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize($file));
ob_clean();
flush();
readfile($file);
exit;
Try using application/force-download instead of text/csv in your Content-Type value.
header("Content-Type: application/force-download; name=\"" . $fileName . "\"");
This will force an actual download box instead of just showing the content in the browser.
Here is some documentation from MIME Application:
Mime application/force-download, which is typically expressed as mime application/x-force-download, is typically used in conjunction with PHP code to trigger a download box rather than for displaying content in a Web browser.
For example, if you had a file on your website that you want the user to download rather than view in the Web browser, you could enter the appropriate mime application/force-download code in the file’s header content type field. Note that mime application/force-download is not a registered MIME type. In addition, when used in PHP code, the preferred spelling of mime application/force-download contains the “x-” prefix.
I don't know if this a good solution, I didn't explore it much, but it seems it's working. It cotroller after I add some data to buffer after headers, before exporting.
header('Content-Type: text/csv; charset=utf-8');
header('Content-Disposition: attachment; filename="'. $fileName . '"');
echo str_pad('', ini_get('output_buffering'));
ob_flush();
flush();
Model_Subscriber1::exportList($listId);
To make it works in controller I added in Zend Bootstrap.php:
/**
* hint to the dispatcher that it should not use output buffering to capture output generated by action controllers.
* By default, the dispatcher captures any output and appends it to the response object body content.
*/
protected function _initFront()
{
$frontController = Zend_Controller_Front::getInstance();
$frontController->setParam('disableOutputBuffering', 1);
}
It look like in this case I get download window in browser quickly and then data are exporting which could take quite a long time. I don't know if this solution is acceptable now. I'd be glad to here your opinion about it. It cause issues with adding empty data to export file. So, I change it controller to.
header('Content-Type: text/csv; charset=utf-8');
header('Content-Disposition: attachment; filename="'. $fileName . '"');
Model_Subscriber1::exportList($listId);
And chang function for export to something like this:
foreach ($mongodbCursor as $subscriber) {
$row = formRow($subscriber);
echo '"' . implode('","', $row) . '"' . "
";
ob_flush();
flush();
}
Your function may want to call flush / ob_flush just before long operation and let the HTTP header send to client before long process.