How to create file in JavaScript from text

Question

I am writing JavaScript code to initiate a download of a file in the browser. I am able to get the bytes of the file in a string and I want to pass the string to a function that creates a file and initiates a download from it.

I have to avoid just storing the file on the server for someone to download through html like:

<a href="./some-file.pdf">file</a>

Here is the code I have so far which works just fine, but I need to modify the extension of the file to change it to match the data, which is the part I havn't figured out.

function download(data, filename = "aserc", type = ".txt") {
    var file = new Blob([data], {type: type});
    if (window.navigator.msSaveOrOpenBlob)
    {
        window.navigator.msSaveOrOpenBlob(file, filename);
    } else  {
        var a = document.createElement("a"), url = URL.createObjectURL(file);
        a.href = url;
        a.download = filename;
        document.body.appendChild(a);
        a.click();
        setTimeout(() => {
            document.body.removeChild(a);
            window.URL.revokeObjectURL(url);  
        }, 0); 
    }
}

this will download a file but it will not be a .txt file. How do I change the type of the file using this code?

blob type should be a MIME type, text/plain perhaps?, not a file extension ... filename should be aserc.txt — Jaromanda X
– Jaromanda X, Commented Aug 21, 2017 at 4:55

Soviut · Accepted Answer · 2017-08-21 07:13:16Z

1

Add the file extension to the name of the file. Like this

a.download = filename + ".txt";

Looking at the docs the Blob object takes in 'plain/text' for the type attribute to specify text this may be something you should keep an eye on, change Blob declaration to

var file = new Blob([data], {type: 'plain/text'});

edited Aug 21, 2017 at 7:13

Soviut

92.2k53 gold badges210 silver badges285 bronze badges

answered Aug 21, 2017 at 6:49

techimperial

312 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to create file in JavaScript from text

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related