Downloading from S3 in node and opening in a new window - angularjs

Question

My Angular 1 application saves files to S3 and allows for a wide variety of files types.
When I retrieve the objects I use the following code:
export function show(req, res) {
const s3 = new aws.S3();
const s3Params = {
Bucket: S3_BUCKET,
Key: req.query.key + ''
};
res.attachment(req.query.key + '');
var fileStream = s3.getObject(s3Params).createReadStream();
fileStream.pipe(res);
}
I would like to open the received file on the client in a new window (just like on the AWS console) but I can't figure out how to go about it.
For example on the client side does not work at all:
.then(
(data) => {
var file = new Blob([data], {type: 'application/pdf'});
var fileURL = URL.createObjectURL(file);
window.open(fileURL);
}
)
I really don't understand how the concept of data streams works.

Answer 1

If you don't have to download pdf, you may open it directly from s3.
s3client.getResourceUrl("your-bucket", "some-path/some-key.jpg");
This will return you url to the file.
So you need code like:
export function show(req, res) {
this.s3client = new aws.S3({
accessKeyId: options.accessKeyId,
secretAccessKey: options.secretAccessKey,
region: options.region
})
let resourceUrl = s3client.getResourceUrl(S3_BUCKET, req.query.key + '');
window.open(resourceUrl, '_blank');
}
I'm sorry, can't test it right now, but try. Should work.

Answer 2

All I had to do was get a signedUrl for the resource for this to work much simpler than what I was trying to do.
export function show(req, res) {
const s3 = new aws.S3();
const s3Params = {
Bucket: S3_BUCKET,
Key: req.query.key + ''
};
s3.getSignedUrl('getObject', s3Params, (err, data) => {
if (err) {
console.log(err);
return res.end();
}
const returnData = {
signedRequest: data,
};
res.write(JSON.stringify(returnData));
res.end();
});
}
and on the client all I have to do is open the link in a new tab:
openDoc(doc) {
this.$http()
.then(
(data) => {
this.$window.open(data.data.signedRequest, '_blank')
}
)
.catch(
(err) => {
this.Notification.error('failed to download attachment');
}
)
}