jQuery Drag-and-Drop Image Upload Functionality - image

Question

I am trying to code my own simple AJAX image upload script via jQuery. I have found some plugins but they are way too customized for what's needed, and I cannot get any of them working properly.
I just want to somehow detect when the user drags and drops an image onto the page. From there I'm sure it's not hard to upload that data and move into a /cache/ directory and allow for further options..
but right now I'm totally stuck with the drag/drop functionality. Literally no idea how I should approach this. What kind of event handler is needed? Will I need to custom code my own event handler? Any advice would be more than appreciated

Answer 1

What kind of event handler is needed?
Drag'n'drop requires a HTML5 browser - but that's pretty much all of them now.
I'd recommend not starting from scratch as there's quite a bit of code needed - I quite like this wrapper that implements it as a jQuery plugin.
http://www.github.com/weixiyen/jquery-filedrop
After defining an element in the document with class div, you can initialise it to accept dropped files with:
function fileSetUploadPercent(percent, divID){
var uploadString = "Uploaded " + percent + " %";
$('#'.divID).text(uploadString);
}
function fileUploadStarted(index, file, files_count){
var divID = getDivID(index, file);
createFileUploadDiv(divID); //create the div that will hold the upload status
fileSetUploadPercent(0, divID); //set the upload status to be 0
}
function fileUploadUpdate(index, file, currentProgress){
//Logger.log("fileUploadUpdate(index, file, currentProgress)");
var string = "index = " + index + " Uploading file " + file.fileName + " size is " + file.fileSize + " Progress = " + currentProgress;
$('#status').text(string);
var divID = getDivID(index, file);
fileSetUploadPercent(currentProgress, divID);
}
function fileUploadFinished(index, file, json, timeDiff){
var divID = getDivID(index, file);
fileSetUploadPercent(100, divID);
if(json.status == "OK"){
createThumbnailDiv(index, file, json.url, json.thumbnailURL);
}
}
function fileDocOver(event){
$('#fileDropTarget').css('border', '2px dashed #000000').text("Drop files here");
}
$(".fileDrop").filedrop({
fallback_id: 'fallbackFileDrop',
url: '/api/upload.php',
// refresh: 1000,
paramname: 'fileUpload',
// maxfiles: 25, // Ignored if queuefiles is set > 0
maxfilesize: 4, // MB file size limit
// queuefiles: 0, // Max files before queueing (for large volume uploads)
// queuewait: 200, // Queue wait time if full
// data: {},
// headers: {},
// drop: empty,
// dragEnter: empty,
// dragOver: empty,
// dragLeave: empty,
// docEnter: empty,
docOver: fileDocOver,
// docLeave: fileDocLeave,
// beforeEach: empty,
// afterAll: empty,
// rename: empty,
// error: function(err, file, i) {
// alert(err);
// },
uploadStarted: fileUploadStarted,
uploadFinished: fileUploadFinished,
progressUpdated: fileUploadUpdate,
// speedUpdated
});
The bit of the web page that accepts uploads has this HTML.
<div class='fileDrop'>
Upload a file by dragging it.
<span id='fileDropTarget'/>
</div>
The file drop works on the outer <div> but it's nice to make a nice big target that says 'DROP HERE' so that users aren't confused about where they need to drop the file.

Answer 2

Probably too late. But you should checkout http://www.dropzonejs.com/