How can i transfer my res.data to Uint8Array

[broairport]

I use axios to get data from my backend .
I print it out using console.log() ,it's an object.I can download it by using "new blob([res.data])"
But when i try to use StreamSaver to download it.i just don't know how can i convert my res.data into Uint8Array.
I've tried to use "new Uint8Array(res.data)" to get Uint8Array but it's empty .
By the way i set responseType as "blob"

[jimmywarting]

I would recommend against using axios...

why?

• b/c axios uses XMLHttpRequest to get data. (ref)
• xhr don't support streaming.
• axios weighs as much as 6.2 kB when minified
• axios don't work within web workers either...
• when you are using xhr to get data then you download everything into memory.
  • you might just as well just use filesaver.js to this end.
• using xhr beats the whole purpose of using streamsaver as it's meant to save you from allocating everything into memory.

only fetch supports streaming...

fetch(url).then(res => {
  res.body.pipeTo(destination)
})

[broairport]

First of all,thank you for your reply.
Is what you said "use the backend to save the file" refered to frontend send file to the backend and backend(server) save it?

[jimmywarting]

I'm suggesting that you shouldn't use axios, fetch, XMLhttpRequest, StreamSaver.js, or FileSaver.js

i'm saying that you should try to navigate to the resource that you want to download. it can be either one of:

• location.href = 'url' redirect
• A hidden iframe that opens the url
• Submitting a <form action="url" method="POST" target="_blank"> in case if you need to post (hidden) data
• or a click on a link element <a href="url" download="filename">

...as long as you respond with a content-disposition attachment header to the response

• You can optionally add support for accept-ranges - this allows you to retry the download if something fails and you can continue from where you left off.
• also you can set the content-type to something like application/octet-stream this will for sure make the browser incompatible of rendering the file on a browser so it will default to saving the file instead.

---

This is basically how StreamSaver works. it sets up a service worker on the clients machine. it opens a url (by navigating to that url) and responds With a Response constructed from a ReadableStream and a content-disposition attachment header. all so that it can emulate a server (backend) and allowing the browser what it is suppose to be doing.

[jimmywarting]

whenever you use ajax do get the data then you prevent the browser from doing what it is supposed to do, then content-disposition attachment header has no value/meaning

[broairport]

Actually,I am doing something with "Range".Why i choose to use fetch is to retry the download from where it left off if something fails.Beacuse i used to think that browser can't retry from where it left off if i use some DOM element to navigate the resource ,in other words, i should implement it munually.And now i understand what you're saying
Thank you very much!jimmy.

[broairport]

What i did is called 喧宾夺主 which means that the wrangling guest robs the place of the host .lol