Download a binary file using JavaScript

Question

I am using the following code to create a text file from the browser. It works when I'm using data:text/plain;charset=utf-8, and the text is plain but when the data is xls, I get a network error and it doesn't work. Can anyone advise me what I'm missing or doing wrong.

function download(filename, text) {
    var element = document.createElement('a');
    element.setAttribute('href', 'data:application/xls;base64,'+text);
    element.setAttribute('download', filename);

    element.style.display = 'none';
    document.body.appendChild(element);

    element.click();

    console.log(text);

    document.body.removeChild(element);
    }

I should note, the code has come from https://ourcodeworld.com/articles/read/189/how-to-create-a-file-and-generate-a-download-with-javascript-in-the-browser-without-a-server

Thanks in advance.

I don't want to use BLOBS.

I think your content type is wrong. Try this: https://stackoverflow.com/questions/2937465/what-is-correct-content-type-for-excel-files — Max, Oct 10 '19 at 15:26

score 1 · Answer 1 · answered Oct 10 '19 at 15:25

1

There is no type as application/xls https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types

Complete IANA List : [ https://www.iana.org/assignments/media-types/media-types.xhtml#application ]

Read this answer : What is correct content-type for excel files?

For BIFF .xls files

application/vnd.ms-excel

For Excel2007 and above .xlsx files

application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

answered Oct 10 '19 at 15:25

Dhananjai Pai

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I change the href to element.setAttribute('href', 'data:application/vnd.ms-excel;base64,'+text); but didn't seem to do any good :( unless I've misunderstood what to do. – MiscellaneousUser Oct 10 '19 at 15:39
what is the text? – Dhananjai Pai Oct 10 '19 at 15:40
It is definately a XLS file that i'm trying to download. – MiscellaneousUser Oct 10 '19 at 15:40
is it base64 encoded ? if not why are you appending base64 before the text as in your comment ? – Dhananjai Pai Oct 10 '19 at 15:41
Ok, I'm getting somewhere now, thx. I assumed it was base64, I've removed it and now its downloading but only 2KB, should be much bigger. – MiscellaneousUser Oct 10 '19 at 15:50
can't help you much without knowing details. create a fiddle if possible – Dhananjai Pai Oct 10 '19 at 16:04

Download a binary file using JavaScript

1 Answers1