Input file onchange check user has selected file

Question

function preview(){
   if(...){//if user have select file
      //do something if input file onchange.
   }else{
      alert('please select a file');
   }
}

<input type='file' name='file' onchange='preview(this);' />

I have an input file, onchange will do something.

However I need to check if user has select the file.

Is anyway to check input file is not empty?

I don't understand. Do you not have selected a file, when the function `preview()` is called? — loveNoHate, Sep 23 '14 at 16:29
http://stackoverflow.com/questions/46219/how-to-determine-if-user-selected-a-file-for-file-upload — Stryner, Sep 23 '14 at 16:30
[stackoverflow.com/q/11860721](http://stackoverflow.com/q/11860721/) as well. — patstuart, Sep 23 '14 at 16:31

score 3 · Accepted Answer · answered Sep 23 '14 at 16:53

Here is my jsfiddle for this -- http://jsfiddle.net/Arindamnayak/estqvh9q/

<input type="file" id="fl" name="fl" onchange="preview()" />

function preview()
{
    var dc = document.getElementById("fl").files;
    if(dc.length == 0)
        alert("no file selected");
}

Input file onchange check user has selected file

1 Answers1