Javascript: changing input file type?

Question

I have a simple HTML file input:

<input type="file" id="file" onchange="__func">

Once I load the file in the input, I call __func:

function __func(event)
{
    let file = event.target.files[0];
        file.type = 'text/csv';
}

Problem is when I attempt to change the file type within __func, either type of file does not change, either I receive the error:

TypeError: "setting getter-only property "type""

How can I dynamically change file type using javascript? I need to do it because I'm sending the file via a FormData wrapper, and because it's plain CSV the content type is not properly detected and set to application/octet-stream automatically.

lry · Accepted Answer · 2020-03-26 09:39:21Z

3

You can use slice method to create a new File Blob.

const blob = file.slice(0, file.size, "text/csv")

answered Mar 26, 2020 at 9:39

lry

7683 silver badges7 bronze badges

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

Collectives™ on Stack Overflow

Javascript: changing input file type?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related