XMLHttpRequest() and outputting csv file

I can successfully generate a csv file by issuing an html form POST to a new开发者_开发百科 window and use PHP to respond with:

header('Content-type: text/csv');
header('Content-Disposition: attachment; filename="'.date("Ymdhis").'.csv"');
print get_lines();

However, this leaves the the window open and blank.

I want to either close the window automatically (on recognition of the Content-Disposition) or I would prefer to ignore the window completely and simply onClick, call XMLHttpRequest() send the form variables to the PHP, generate the data file and then prompt the user to save or open.

I have tried:

var xhReq = new XMLHttpRequest();
var parameters = "";

for ( i=0; i<formObj.elements.length; i++ ) {
  parameters += formObj.elements[i].name + "=" + encodeURI( formObj.elements[i].value ) + "&";
}

xhReq.open("POST", outputLocation, false);
xhReq.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhReq.setRequestHeader("Content-length", parameters.length);
xhReq.setRequestHeader("Connection", "close");
xhReq.send(parameters);

document.write(xhReq.responseText);

but this doesn't work because the response is simply printed as text to screen.

What I really want, is once I have all the data, to issue a new header() call without opening a new window - is this possible using javascript?

You need to send the POST request in a new window in order to do this. I would suggest that you create a hidden form and set it's target attribute to _blank

You should set the Content-disposition HTTP header on the server-side to force a download.

You are calling document.write, which dumps a text string into the browser, this is likely not what you wish to do.