drag drop files into standard html file input
These days we can drag & drop files into a special container and upload them with XHR 2. Many at a time. With live progress bars etc. Very cool stuff. Example here.
But sometimes we don't want that much coolness. What I'd like is to drag & drop files -- many at a time -- into a standard HTML file input: <input type=file multiple>.
Is that possible? Is there some way to 'fill' the file input with the right filenames (?) from the file drop? (Full filepaths aren't available for file system security reasons.)
Why? Because I'd like to submit a normal form. For all browsers and all devices. The drag & drop is just progressive enhancement to enhance & simplify UX. The standard form with standard file input (+ multiple attribute) will be there. I'd like to add the HTML5 enhancement.
edit
I know in some browsers you can sometimes (almost always) drop files into the file input itself. I know Chrome usually does this, but sometimes it fails and then loads the file in the current page (a big fail if you're filling out a form). I want to fool- & browserproof it.
Solution 1:
The following works in Chrome and FF, but i've yet to find a solution that covers IE10+ as well:
// dragover and dragenter events need to have 'preventDefault' called
// in order for the 'drop' event to register.
// See: https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Drag_operations#droptargets
dropContainer.ondragover = dropContainer.ondragenter = function(evt) {
evt.preventDefault();
};
dropContainer.ondrop = function(evt) {
// pretty simple -- but not for IE :(
fileInput.files = evt.dataTransfer.files;
// If you want to use some of the dropped files
const dT = new DataTransfer();
dT.items.add(evt.dataTransfer.files[0]);
dT.items.add(evt.dataTransfer.files[3]);
fileInput.files = dT.files;
evt.preventDefault();
};<!DOCTYPE html>
<html>
<body>
<div id="dropContainer" style="border:1px solid black;height:100px;">
Drop Here
</div>
Should update here:
<input type="file" id="fileInput" />
</body>
</html>You'll probably want to use addEventListener or jQuery (etc.) to register your evt handlers - this is just for brevity's sake.
Solution 2:
I made a solution for this.
$(function () {
var dropZoneId = "drop-zone";
var buttonId = "clickHere";
var mouseOverClass = "mouse-over";
var dropZone = $("#" + dropZoneId);
var ooleft = dropZone.offset().left;
var ooright = dropZone.outerWidth() + ooleft;
var ootop = dropZone.offset().top;
var oobottom = dropZone.outerHeight() + ootop;
var inputFile = dropZone.find("input");
document.getElementById(dropZoneId).addEventListener("dragover", function (e) {
e.preventDefault();
e.stopPropagation();
dropZone.addClass(mouseOverClass);
var x = e.pageX;
var y = e.pageY;
if (!(x < ooleft || x > ooright || y < ootop || y > oobottom)) {
inputFile.offset({ top: y - 15, left: x - 100 });
} else {
inputFile.offset({ top: -400, left: -400 });
}
}, true);
if (buttonId != "") {
var clickZone = $("#" + buttonId);
var oleft = clickZone.offset().left;
var oright = clickZone.outerWidth() + oleft;
var otop = clickZone.offset().top;
var obottom = clickZone.outerHeight() + otop;
$("#" + buttonId).mousemove(function (e) {
var x = e.pageX;
var y = e.pageY;
if (!(x < oleft || x > oright || y < otop || y > obottom)) {
inputFile.offset({ top: y - 15, left: x - 160 });
} else {
inputFile.offset({ top: -400, left: -400 });
}
});
}
document.getElementById(dropZoneId).addEventListener("drop", function (e) {
$("#" + dropZoneId).removeClass(mouseOverClass);
}, true);
})#drop-zone {
/*Sort of important*/
width: 300px;
/*Sort of important*/
height: 200px;
position:absolute;
left:50%;
top:100px;
margin-left:-150px;
border: 2px dashed rgba(0,0,0,.3);
border-radius: 20px;
font-family: Arial;
text-align: center;
position: relative;
line-height: 180px;
font-size: 20px;
color: rgba(0,0,0,.3);
}
#drop-zone input {
/*Important*/
position: absolute;
/*Important*/
cursor: pointer;
left: 0px;
top: 0px;
/*Important This is only comment out for demonstration purposes.
opacity:0; */
}
/*Important*/
#drop-zone.mouse-over {
border: 2px dashed rgba(0,0,0,.5);
color: rgba(0,0,0,.5);
}
/*If you dont want the button*/
#clickHere {
position: absolute;
cursor: pointer;
left: 50%;
top: 50%;
margin-left: -50px;
margin-top: 20px;
line-height: 26px;
color: white;
font-size: 12px;
width: 100px;
height: 26px;
border-radius: 4px;
background-color: #3b85c3;
}
#clickHere:hover {
background-color: #4499DD;
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div id="drop-zone">
Drop files here...
<div id="clickHere">
or click here..
<input type="file" name="file" id="file" />
</div>
</div>The Drag and Drop functionality for this method only works with Chrome, Firefox and Safari. (Don't know if it works with IE10), but for other browsers, the "Or click here" button works fine.
The input field simply follow your mouse when dragging a file over an area, and I've added a button as well..
Uncomment opacity:0; the file input is only visible so you can see what's going on.
Solution 3:
This is the "DTHML" HTML5 way to do it. Normal form input (which IS read only as Ricardo Tomasi pointed out). Then if a file is dragged in, it is attached to the form. This WILL require modification to the action page to accept the file uploaded this way.
function readfiles(files) {
for (var i = 0; i < files.length; i++) {
document.getElementById('fileDragName').value = files[i].name
document.getElementById('fileDragSize').value = files[i].size
document.getElementById('fileDragType').value = files[i].type
reader = new FileReader();
reader.onload = function(event) {
document.getElementById('fileDragData').value = event.target.result;}
reader.readAsDataURL(files[i]);
}
}
var holder = document.getElementById('holder');
holder.ondragover = function () { this.className = 'hover'; return false; };
holder.ondragend = function () { this.className = ''; return false; };
holder.ondrop = function (e) {
this.className = '';
e.preventDefault();
readfiles(e.dataTransfer.files);
}#holder.hover { border: 10px dashed #0c0 !important; }<form method="post" action="http://example.com/">
<input type="file"><input id="fileDragName"><input id="fileDragSize"><input id="fileDragType"><input id="fileDragData">
<div id="holder" style="width:200px; height:200px; border: 10px dashed #ccc"></div>
</form>It is even more boss if you can make the whole window a drop zone, see How do I detect a HTML5 drag event entering and leaving the window, like Gmail does?