NodeJS + Express: Download ZIP file using fs.createReadStream works in all browsers except Firefox

Question

I have this piece of code in a Node.js + Express application to serve ZIP files containing images to the user when visiting a /download route.

        res.setHeader('Content-type', 'application/zip');

        let fileStream = fs.createReadStream(pathToZip);
        fileStream.pipe(res);

        fileStream.on('error', function (error) {
            /** error handling happening here **/
        });

        fileStream.on('close', function () {
            /** Close Filestream and delete ZIP File from Server **/
            fileStream.destroy();
            fs.unlink(path);
        });

Downloading the files work in Chrome, Safari and even IE (latest versions). When trying to download with Firefox (Mac + Windows, FF Quantum 57.0.4) no download prompt appears.

The Firefox network inspector shows me a successful XHR request for the /download route with a long string of characters and numbers as the response (Charactercount for the response: 2097152 characters).

Am I missing something?

Thanks in advance!

score 3 · Answer 1 · answered Jan 24 '18 at 15:51

3

Try to set Content-Disposition header with the value of attachment to indicate to firefox that the file should be downloaded:

res.setHeader('Content-Disposition', 'attachment');

answered Jan 24 '18 at 15:51

YouneL

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thank you for your reply! unfortunately this does not make it work. i can see that `Content-Dispoition` is set to `attachment` in the XHR Request but still there is no download prompt in firefox. – Maximilian Schmidt Jan 24 '18 at 16:18
What happen if you try `res.setHeader('Content-Disposition', 'attachment; filename=file.zip');` – YouneL Jan 24 '18 at 16:21
was just about to edit my comment above, but it doesnt let you edit it if 5 mins have passed. so, yes i tried that too. it does not work neither with `res.setHeader('Content-Disposition', 'attachment');` nor `res.setHeader('Content-Disposition', 'attachment;filename=test.zip');` – Maximilian Schmidt Jan 24 '18 at 16:25
have you checked the `Always ask you where to save file` option in firefox setting – YouneL Jan 24 '18 at 16:30
Also read this post [https://support.mozilla.org/en-US/questions/978859](https://support.mozilla.org/en-US/questions/978859) maybe this prb is related to your firefox config, not express – YouneL Jan 24 '18 at 16:35
yes, i have checked that. i start to believe that its not a node / express issue but a firefox issue. i do the http request to the `/download` route via angulars `$http`-service. as a `responseType` i choose `arraybuffer`. it seems that firefox has problems with this `responseType`. i`ll dig deeper – Maximilian Schmidt Jan 24 '18 at 16:43
yes probably, try `application/octet-stream` instead of `application/zip` – YouneL Jan 24 '18 at 16:50
same problem with `application/octet-stream`. chrome, safari etc. work, firefox doesnt prompt the download :/ i come to think that the problem is actually that firefox doesnt handle the `responseType: 'arraybuffer'` argument from angulars `$http` call correctly. [some](https://stackoverflow.com/questions/35413323/angularjs-send-files-to-download-in-firefox) people pointed to the same problem and i try to update my frontend code accordingly. maybe that could be the solution? – Maximilian Schmidt Jan 24 '18 at 17:07
ok, so yeah. it was a wrong implementation in my frontend code which starts the download. because i am using blobs to download the file, i created a fake `` tag based on [this](https://stackoverflow.com/a/32226068/5779014) answer but i had an error there because why not... apparently the error only affected firefox. anyways, thanks for your help and pointing me in the right direction! – Maximilian Schmidt Jan 24 '18 at 17:19
You are welcome, but please add an answer for the future readers – YouneL Jan 24 '18 at 17:27
what is the appropriate thing to do now? should i mark your answer as correct because it was part of the solution (`Content-Disposition`-Header) or answer my own question and describing both parts of the problem? – Maximilian Schmidt Jan 24 '18 at 17:29

NodeJS + Express: Download ZIP file using fs.createReadStream works in all browsers except Firefox

1 Answers1