Scott May Scott May - 2 months ago 10
PHP Question

PHP - Bootstrap modal dialog, pick date, download CSV - can't get browser to save the file

I'm using Bootstrap to show a page, some of it is an extract of data. I've added a download button that brings up a modal dialog, including a date range picker, a close and download buttons to allow downloading a larger range of that data.

An extract of the Modal code:

<div class="modal-header">
<button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
<h3 class="modal-title" id="DownloadModalLabel">Download Data </h3>
</div>
<div class="modal-body">
<form id="download_form" action="api-dl.php" method="get">
<div class="form-group">
<label for="channel-name" class="control-label">Download Period:</label>
<input type="text" name="daterange" value="<?php echo $DownloadDateStart . " - " . $DownloadDateEnd; ?>" />
</div>
<div class="form-group hidden">
<input type="text" id="channel-id" name="channel-id" class="channel-id" value="ha" />
<input type="text" name="site-id" class="site-id" value="<?php echo $SITE; ?>" />
</div>
</form>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
<button type="button" id="submitForm" class="btn btn-primary" data-dismiss="modal">Download CSV</button>
</div>


Further down I have a script responds to the submit button:

$(document).ready(function () {
$("#download_form").on("submit", function(e) {
var postData = $(this).serializeArray();
var formURL = $(this).attr("action");
$.ajax({
url: formURL,
type: "GET",
data: postData,
});
e.preventDefault();
});
$("#submitForm").on('click', function() {
$("#download_form").submit();
});
});


You'll note that I call a php file "api-dl.php" to extract data and respond with a CSV file. Cut back to a bare minimum fake one line response that file looks like:

header('Content-Disposition: attachment; filename="12345678.csv";');
header('Content-Type: "text/csv"');
header("Content-Length: 32");
header("Cache-Control: no-cache, no-store, must-revalidate");
header("Pragma: no-cache");
header("Expires: 0");
//
echo '"15/10/2016", "12:00", "1.234\n"';


At this point I've tried lots of flushing and outputting to php output stream and the like. Always I get in the inspect pane on my browser:

Request Headers:

Accept:*/*
Accept-Encoding:gzip, deflate, sdch
Accept-Language:en-GB,en-US;q=0.8,en;q=0.6
Connection:keep-alive
Cookie:PHPSESSID=.....
Host:r .... .net.au
Referer:http://r .... .net.au/site.php?region=Test&site=Test
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.90 Safari/537.36 Vivaldi/1.4.589.11
X-Requested-With:XMLHttpRequest


Response Headers:

Cache-Control:no-cache, no-store, must-revalidate
Connection:Keep-Alive
Content-Disposition:attachment; filename="12345678.csv";
Content-Length:32
Content-Type:"text/csv"
Date:Sat, 24 Sep 2016 00:53:13 GMT
Expires:0
Keep-Alive:timeout=5, max=100
Pragma:no-cache
Server:Apache/2.4.18 (Ubuntu)


To my mind that looks right I've tried 1,248 variations on this theme. In the "Response" tab I see the response I expect:

"15/10/2016", "12:00", "-1.234"


But for the life of me I can't make a browser download that.

I have seen some Javascript that looked nice but the data isn't available on the client side, it's in a database on the server.

I can't be missing much I think - what do you think it could be?

Answer

This works fine. forcing a download, you can redirect the current page to the download link. Ref: Download CSV file using "AJAX"

<script type="text/javascript">
$(document).ready(function () {
    $("#download_form").on("submit", function(e) {
        $('#wait-animation').show(); /* If required show animation */
        var postData = $(this).serializeArray();
        var site_id = $('.site-id').val();  
        var channel_id = $('.channel-id').val();            
        var daterange = $('.daterange').val();      
        document.location.href = $(this).attr("action")+"?site_id"+site_id+"&daterange="+daterange;
        /*e.preventDefault();*/
        $('#wait-animation').hide(); /* hide animation after download completes*/
  });
  $("#submitForm").on('click', function() {
    $("#download_form").submit();
  });
});
</script>