create csv file javascript
$("#download_1").click(function() {
var json_pre = '[{"Id":1,"UserName":"Sam Smith"},{"Id":2,"UserName":"Fred Frankly"},{"Id":1,"UserName":"Zachary Zupers"}]';
var json = $.parseJSON(json_pre);
var csv = JSON2CSV(json);
var downloadLink = document.createElement("a");
var blob = new Blob(["ufeff", csv]);
var url = URL.createObjectURL(blob);
downloadLink.href = url;
downloadLink.download = "data.csv";
document.body.appendChild(downloadLink);
downloadLink.click();
document.body.removeChild(downloadLink);
});