NodeJS - prompt download CSV file - node.js

Question

I'm trying to get - after some promises have been executed - a CSV result back together with a status reponse having details.
The response does get me the data for the CSV but I cannot seem to get the browser to download this data into a CSV file.
router.post('/getSalesOrders', function (request, response) {
var data = request.body;
salesOrderActions.retrieveSalesOrders(data) //
.then(function (result) {
response.setHeader('Content-disposition', 'attachment; filename=testing.csv');
response.set('Content-Type', 'text/csv');
response.json(result[0].message).send(result[0].file);
})
.catch(function (err) {
console.log(err);
if (err.statusCode) {
response.json(err);
}
else {
var error = output.getCriticalErrorResult(c.titles.SERVICE_CRITICAL_ERROR, c.messages.UNKNOWN_ERROR, err.message);
response.json(error);
}
});
});
My result object gets created in the salesOrderActions:
I am here using npm package json2csv
var fields = ['id',.....];
var csv = csvParser({ data: unmatchedLines, fields: fields });
return {
file: csv,
message:
output.getSuccessResult(
titles.SALES_ORDER_SUCCESS_RETRIEVAL,
salesDataForModel.identifier
)
}
My response to the browser is as follows:
So my message isn't sent it seems and I do get the CSV data but not as a file to download.
How can I manage that?
As a sidenote maybe, my front-end is React
EDIT
Response with octed headers:

Answer 1

Try:
sending Content-Type before Content-Disposition
quoting the filename: filename="testing.csv"
Also HTTP headers are case insensitive, so it should not make a difference, but you should write Content-Disposition (capital D).
response.set('Content-Type', 'text/csv');
response.setHeader('Content-Disposition', 'attachment; filename="testing.csv"');
If this does not work you can change the Content-Type to application/octet-stream
This always forces the browser to download the data sent from the server.

Answer 2

Try this code:
router.post('/getSalesOrders', function (request, response) {
var data = request.body;
var fs = require('fs');
salesOrderActions.retrieveSalesOrders(data) //
.then(function (result) {
//**********
var file = "testing.csv";
response.setHeader('Content-disposition', 'attachment; filename=testing.csv');
response.set('Content-Type', 'text/csv');
var filestream = fs.createReadStream(file);
filestream.pipe(res);
//*********
})
.catch(function (err) {
console.log(err);
if (err.statusCode) {
response.json(err);
}
else {
var error = output.getCriticalErrorResult(c.titles.SERVICE_CRITICAL_ERROR, c.messages.UNKNOWN_ERROR, err.message);
response.json(error);
}
});
});

Answer 3

So actually it turns out it is because I'm doing an Ajax request which doesn't - by default - prompt the browser to download any files.
What I did in the end:
router.post('/getSalesOrders', function (request, response) {
var data = request.body;
salesOrderActions.retrieveSalesOrders(data)
.then(function (result) {
response.json(result);
})
.catch(function (err) {
//...
});
});
And then in my front-end, when receiving the result:
salesOrderService.retrieveSalesOrderData()
.then(function (result) {
self.convertAndDownloadCsv(result.unmatchedLines);
});
convertAndDownloadCsv: function (data) {
if (data && data.length > 0) {
var csvData = csvProcessor({ //using csv2json node js package
data: data,
quotes: '',
del: ';'
});
var filename = "unmatchedLinesFromSalesOrders.csv";
var blob = new Blob([csvData], { type: 'text/csv;charset=utf-8;' });
if (navigator.msSaveBlob) { // IE 10+
navigator.msSaveBlob(blob, filename);
} else {
var link = document.createElement("a");
if (link.download !== undefined) { // feature detection
// Browsers that support HTML5 download attribute
var url = URL.createObjectURL(blob);
link.setAttribute("href", url);
link.setAttribute("download", filename);
link.style.visibility = 'hidden';
document.body.appendChild(link);
link.click();
document.body.removeChild(link);
}
}
}
}
More info can be found here