In JavaScript can I make a “click” event fire prog

Question

I'd like to make a click event fire on an <input type="file"> tag programmatically.

Just calling click() doesn't seem to do anything or at least it doesn't pop up a file selection dialog.

I've been experimenting with capturing events using listeners and redirecting the event, but I haven't been able to get that to actually perform the event like someone clicked on it.

Answer 1

This worked for me:

<script>
    function sel_file() {
        $("input[name=userfile]").trigger('click');
    }  
</script>

<input type="file" name="userfile" id="userfile" />

<a href="javascript:sel_file();">Click</a>

Answer 2

Hey this solution works. for download we should be using MSBLOB

$scope.getSingleInvoicePDF = function(invoiceNumberEntity) {
   var fileName = invoiceNumberEntity + ".pdf";
   var pdfDownload = document.createElement("a");
   document.body.appendChild(pdfDownload);

   AngularWebService.getFileWithSuffix("ezbillpdfget",invoiceNumberEntity,"pdf" ).then(function(returnedJSON) {
       var fileBlob = new Blob([returnedJSON.data], {type: 'application/pdf'});
       if (navigator.appVersion.toString().indexOf('.NET') > 0) { // for IE browser
           window.navigator.msSaveBlob(fileBlob, fileName);
       } else { // for other browsers
           var fileURL = window.URL.createObjectURL(fileBlob);
           pdfDownload.href = fileURL;
           pdfDownload.download = fileName;
           pdfDownload.click();      
       }
   });
};

For AngularJS or even for normal javascript.

Answer 3

I was researching this a while ago because I wanted to create a custom button that would open the file dialog and start the upload immediately. I just noticed something that might make this possible - firefox seems to open the dialog when you click anywhere on the upload. So the following might do it:

1. Create a file upload and a separate element containing an image that you want to use as the button
2. Arrange them to overlap and make the file element backgroud and border transparent so the button is the only thing visible
3. Add the javascript to make IE open the dialog when the button/file input is clicked
4. Use an onchange event to submit the form when a file is selected

This is only theoretical since I already used another method to solve the problem but it just might work.

Answer 4

For those who understand that you have to overlay an invisible form over the link, but are too lazy to write, I wrote it for you. Well, for me, but might as well share. Comments are welcome.

HTML (Somewhere):

<a id="fileLink" href="javascript:fileBrowse();" onmouseover="fileMove();">File Browse</a>

HTML (Somewhere you don't care about):

<div id="uploadForm" style="filter:alpha(opacity=0); opacity: 0.0; width: 300px; cursor: pointer;">
    <form method="POST" enctype="multipart/form-data">
        <input type="file" name="file" />
    </form>
</div>

JavaScript:

function pageY(el) {
    var ot = 0;
    while (el && el.offsetParent != el) {
        ot += el.offsetTop ? el.offsetTop : 0;
        el = el.offsetParent;
    }
    return ot;
}

function pageX(el) {
    var ol = 0;
    while (el && el.offsetParent != el) {
        ol += el.offsetLeft ? el.offsetLeft : 0;
        el = el.offsetParent;
    }
    return ol;
}

function fileMove() {
    if (navigator.appName == "Microsoft Internet Explorer") {
        return; // Don't need to do this in IE. 
    }
    var link = document.getElementById("fileLink");
    var form = document.getElementById("uploadForm");
    var x = pageX(link);
    var y = pageY(link);
    form.style.position = 'absolute';
    form.style.left = x + 'px';
    form.style.top = y + 'px';
}

function fileBrowse() {
    // This works in IE only. Doesn't do jack in FF. :( 
    var browseField = document.getElementById("uploadForm").file;
    browseField.click();
}

Answer 5

This code works for me. Is this what you are trying to do?

<input type="file" style="position:absolute;left:-999px;" id="fileinput" />
<button  id="addfiles" >Add files</button>

<script language="javascript" type="text/javascript">
   $("#addfiles").click(function(){
      $("#fileinput").click();
   });
</script>

Answer 6

it's not impossible:

var evObj = document.createEvent('MouseEvents');
evObj.initMouseEvent('click', true, true, window);  
setTimeout(function(){ document.getElementById('input_field_id').dispatchEvent(evObj); },100);

But somehow it works only if this is in a function which was called via a click-event.

So you might have following setup:

html:

<div onclick="openFileChooser()" class="some_fancy_stuff">Click here to open image chooser</div>
<input type="file" id="input_img">

JavaScript:

    function openFileChooser() {
      var evObj = document.createEvent('MouseEvents');
      evObj.initMouseEvent('click', true, true, window);  
      setTimeout(function()
      { 
        document.getElementById('input_img').dispatchEvent(evObj);      
      },100);      
    }