javascript - Generating download file in memory for user to download with file name user set -

i'm generating file using javascript user download looks so:

<a href="data:application/octet-stream;charset=utf-8;base64,zm9vigjhcg==">text file</a> 

what need file name user set when saved file can display on website.

how can achieve that?

simple answer is: can't.

complicated answer is:

you can create script pre-set name of file user. create pop-up or prompt ask naming file. after can edit download attribute javascript , user download file name. (if doesn't change in download dialog) this:

var filename = prompt("please name file", "originalfilename"),  filelink = document.getelementbyid('file');  if(filename!= null){    filelink.download = filename;    filelink.innerhtml = filename;  }

<a download='originalfilename' id="file" href="data:application/octet-stream;charset=utf-8;base64,zm9vigjhcg==">text file</a>

live example on https://jsfiddle.net/6o2fxcvd/1/