Not sure if there was a fix in NextJs 15, can't seem to find the PR

what are you trying to archive? Why do you want to have a blob? What#s your goal for you app?

I want to download an excel file from an external api, i assume the only possible way in next 14.2 is to use a route handler

But still in Next 15 the blob can be returned from the server action which is great but im on 14.2 sadly

use s3 for serving files

yea, that you want to download something was clear for me. What do you want to do with this file after you downloaded it?

Just download it on my computer ?

I ended up using a route handler but just curios if next team did something regarding blobs in server action on v15

when you just want to download a file to your computer, why do you want to do it with a route handler or server action?

Wouldn't it be waaaay easier to open the link via window.open or via a <Link href='https://yourlink.com/' /> tag?

related: https://nextjs-forum.com/post/1267973501680091156

Because I need to have an endpoint for this, its either server action or route handler, just the thing that return blob in server action works in next 15 but doesnt in 14

just to get this right you want to do something like this:

https://example.com/api/your/file/route

to get a file instead of just using the file url itself:

https://example.com/your/file.xls

Is that correct?

The file is excel

the api should return a file as response

yes to download the file, right?

yes

using a server action in next15

const response = fetch(externalapi that returns a file)
return response.blob()

why do you want to build an extra api route (or server action) just to download a file?

thats a good question, because I use NextJs as bff

as bff

?

client requests need to go through next server

backend for frontend pattern

so like the server must allow that the user can see the file?

what do you mean

you said:

client requests need to go through next server

So I assume the request would look like this:
Client --- Request ---> NextJs Server --- Serve File ---> Client

And the only reason I see right now is because the file shouldn't be directly public

Yes

you are correct

client - next server - external server

left to right and back

and let me guess: the external server need some kind of auth to serve the file, right?

yes

and only your nextjs server knows this secret, right?

yeah a token saved in cookies

thats why im going to next server actually, to receive it and request that file in that external server

does the client knows the secret?

saved in cookies

nope

just so I dont take your time, i managed to make it work using a route handler, im just confused as to why v15 allows to return a blob from server action to client while v14 doesnt

the cookies are saved from the client

those cookies have secure flags which cannot be accessed using javascript

httponly and secure

the cookies will be attached to the server request, right?

Depends which server you are asking for, the external server has a different domain

hmm got it. When your nextjs request something from your external server, what does your external server return? An url to the excl file?

no its a file, I would be more than happy if it returned a url tbh hahahahahah

uff... let me guess, you have no control over the external backend?

I like the way you think

yes thats a separate team

but on second thoughts they could make it so it returned an url that points to the storage but I think they generate this excel on the fly

ah that sucks. They generating the file so this file need to be stored somewhere, right? Or is it just "saved" inside the request

By them?

Not sure if they need to save it somewhere, maybe it should be generated with fresh data all the time

Im not sure though, but we can assume this is the way they decided to do it

yea, they can either replace the data or generate a new file everytime and return you the file url. Tbh that sounds a bit like they using excl tables to have a "database"

Yeah, I believe they need to calculate the data everytime i click that generate excel button

so, no need to save it on a storage and return the url IMO

Would be nice if a guy from nextjs approves that returning a blob from server action wouldnt be able in v14 but is in 15

yea, makes sense. Are you using next14 or next15 rn?

14 sadly, can’t really upgrade to 15 cause of the breaking changes

but im happy with the route handler solution

thats a bit more work but it is what it is

yea, I guess that's the only thing that you can do. Would be way better if your other team supports you a bit more and "helps" you a bit there, but I guess that's not possible

But you agree with me that v15 supports returning blob from server action while v14 doesnt just so I don’t think im tripping😂😂

haha I just tried to find other solutions for you, that's why I asked so many details sorry xD
It still was a fun thread 🤣
Thanks for being that communicative

Tbh your questions were spot on, you need to check the bff approach though lol

knowing that a lot of apps have an external backend that depends on

Remix has a section just for that

We depend heavily on this approach in order to benefit from nextjs server goods

If you ask me, application that hides behind auth are better built using plain react but I chose to follow the meta framework hype in 2024

Interesting approach. I like to serve mostly everything through nextjs and there are things like database, files, ... I am using external services. Like:
S3 for file save (or R2)
Cloudflare, Cloudfront or BunnyCDN for serving files
My VPS for database
...
Like that none of the services knows each other and they can match perfectly together and every service can do what it can do best

Yeah but those give you apis that fits great with nextjs right?

yea, I think that would make more network request instead of less:

Client -> NextJs Server -> External Server (2 requests)

Instead of:
Client -> External Server (1 request)

Normally the client auth himself via token or session or whatever and if there isn't anything, the request will be declined

Im aware of 2 round trips, not a fan of it though but everything has trade offs these days

no not really. They all depend on web standards so they can be integrated everywhere. S3 upload is just a post request with the file. BunnyCDN just points to the S3 origin and provides just the url. My database just creates the database and handles connections with queries.
None of these services are "special" or "especially made" for nextjs

In my case the external server is .NET so yeah bff is the only way😂😂

but you use an orm right?

think my situation like so.

I dont have control over anything, I just know the api endpoints that I need to communicate with and leave the rest to the other team

yea, sometimes that happens. For one of my customers it's also .NET backend, but he is very supportive. If I ask him "can you return me a url to the file instead of the buffer", he directly does that. I wish every developer could experience this 🤣

yes drizzle. This one is also not directly made for nextjs. It also uses just postgres standards these can be easily integrated with nodejs

that sounds like you are just building the frontend, but want to be save when they somewhen say "can you add this and that as well" and then you need your own backend xD

thats good bro, but I dont have this luxury, but even with 2 round trips the communication seems to be very fast

spot on again😂 We help them to generate pdf with react pdf cause they hate it, maybe every backend does hahahahahaha

haha I hate it as well 🤣

So i still believe that in those circumstances we didn’t have to follow the metaframework hype and stick to react with tanstack router but we switched anyways.

But we needed some SEO support and the next thing I know we are all in nextjs whether its an app behind auth or just a public app hahahahaha

told ya hahaha

But its nice having the possibility to do backend stuff too, you never know when you need it

yea true. nextjs helps there a lot and it's easy to rank on google when the correct content is there

hopefully they never ask for the source code because they have another frontend dev and this "other frontend dev" just knows react or something only frontend. Then you are f***t 🤣

hahahahaha you tell me bro, I spent the whole year figuring out the best approach to use nextjs with an external backend

Actually the backend team are guys from the same company, so no worries for that lol

Yeah, I am a technical leader so I try to transfer the knowledge to all of the front team, I understand those who have no idea about backend and jump to Nextjs

yea, all the best with your project ^^

plural😂😂♥️

Still gotta find the pull request for the blob fix hahahahahah