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jQuery drag and drop - checking for a drop outside a droppable

My apologies if this was answered in another question, I could not find an answer specific to my problem!
I'm trying to test whether a jQuery draggable is being dropped outside of a legal droppable. This would normally be solved 90% of the time by reverting the draggable, but I don't want to do that. Instead, I want to do one thing if the draggable is dropped onto a droppable (working great!), and something else if it is dropped outside of all possible droppables (currently getting the better of me!).
In a nutshell:
jQuery('#droppable').droppable(
{
accept: '#draggable',
drop: function(event, ui)
{
// awesome code that works and handles successful drops...
}
});
jQuery('#draggable').draggable(
{
revert: false,
stop: function()
{
// need some way to check to see if this draggable has been dropped
// successfully or not on an appropriate droppable...
// I wish I could comment out my headache here like this too...
}
});
I feel like I'm missing something really obvious...thanks in advance for any help!

Because the droppable's drop event fires before the draggable's stop event, I think you can set a flag on the element being dragged in the drop event like so:
jQuery('#droppable').droppable(
{
accept: '#draggable',
drop: function(event, ui)
{
ui.helper.data('dropped', true);
// awesome code that works and handles successful drops...
}
});
jQuery('#draggable').draggable(
{
revert: false,
start: function(event, ui) {
ui.helper.data('dropped', false);
},
stop: function(event, ui)
{
alert('stop: dropped=' + ui.helper.data('dropped'));
// Check value of ui.helper.data('dropped') and handle accordingly...
}
});

I see that you already got an answer; anyway I had this same problem today and I solved it this way:
var outside = 0;
// this one control if the draggable is outside the droppable area
$('#droppable').droppable({
accept : '.draggable',
out : function(){
outside = 1;
},
over : function(){
outside = 0;
}
});
// this one control if the draggable is dropped
$('body').droppable({
accept : '.draggable',
drop : function(event, ui){
if(outside == 1){
alert('Dropped outside!');
}else{
alert('Dropped inside!');
}
}
});
I needed that because I couldn't change the options of my draggables, so I had to work only with droppables (I needed it inside the awesome FullCalendar plugin).
I suppose it could have some issues using the "greedy" option of droppables, but it should work in most cases.
PS: sorry for my bad english.
EDIT: As suggested, I created the version using the jQuery.data; it can be found here : jsfiddle.net/Polmonite/WZma9/
Anyway jQuery.data documentation say:
Note that this method currently does not provide cross-platform support for setting data on XML documents, as Internet Explorer does not allow data to be attached via expando properties.
(meaning that it doesn't work on IE prior to 8)
EDIT 2: As noted by #Darin Peterson , the previous code doesn't work with more than one drop-area; this should fix that issue: http://jsfiddle.net/Polmonite/XJCmM/
EDIT 3: Example from EDIT 2 has a bug. If I drag "Drag me!" to the bottom droppable, then drop "Drag me too" to the upper droppable and then drop "Drag me too" outside, it alerts "Dropped inside!" So, don't use it.
EDIT 4: As noted by #Aleksey Gor, the example in Edit 2 was wrong; actually, it was more of an example to explain how to loop through all the draggables/droppables, but I actually forgot to remove the alert messages, so it was pretty confusing. Here the updated fiddle.

Try to use the event "out" of a droppable element.
This is the documentation
"This event is triggered when an accepted draggable is dragged out (within the tolerance of) this droppable."
If I'm right, this is what you need.
What is also possible is to create an element overlay over the whole page. If the element is dropped there you fire your event. Not the best, but I think the only way to do it. Because you need some other "droppable" item to fire these events.

The advantage of the following example, is that you don't need to change or know about the droppable code:
The draggable revert property can have a function(value){}. A value is passed as argument, indicating if helper was dropped onto an element (the drop element), or 'false' if not dropped on an element (drop outside or not accepted).
Note: you need to return the correct bool value from that
revert-function, in order to tell the helper to revert or not
(true/false). True means yes, take the helper back to its original
position, by moving it back in a slow motion (out-of-the-box). False means no, just
remove the helper abdruptly. Setting the revert property to 'invalid',
is a shortcut of saying
'yes, if dropped outside, then revert helper'
'no, if dropped on a droppable element and accepted, then kill the helper right away'.
My guess is that you can add current ui helper to draggable container with data property during start event. Then pick it up in the revert function from the data property. Then add a property to the helper, indicating if it was dropped or not. Then ultimately in the stop event, check this data property value, and do what you intended.
Order of event/function calls for draggable:
start-revert-stop
This could be an example:
jQuery('#draggable').draggable(
{
start: function(event, ui) {
$(this).data('uihelper', ui.helper);
},
revert: function(value){
var uiHelper = (this).data('uihelper');
uiHelper.data('dropped', value !== false);
if(value === false){
return true;
}
return false;
},
stop: function(event, ui)
{
if(ui.helper.data('dropped') === true){
// handle accordingly...
}
}
});
You can even return true in the revert function, and just remove the helper during the stop event instead, depending on the data('dropped') value with ui.helper.remove(). Or you could even explode it with CSS3 if you still have a bad day ;)

I add the solution I adopted since you can understand this very easily from the css classes of the object you are moving:
jQuery('#draggable').draggable({
stop: function(event, ui) {
if (ui.helper.hasClass('ui-draggable-dragging')) {
console.log('dropped out');
} else {
console.log('dropped successfully');
}
}
});

Old question and old answers mean that this "may" be a new solution. You (maybe) also wanted, as the question states, to know IF a draggable was dropped outside of a droppable. For me, in at least 95% of the cases, I don't really care IF, I just want things to go back to how they were without any changes being made WHEN that happens.
Setting revert to the string invalid accomplishes the desired behavior without any extra code or funky things to do.
$( '#draggable' ).draggable({
revert: "invalid",
stop: function( event, ui )
{
// whatever
}
});
Again, it won't tell you "if it was dropped outside of a droppable," but it will revert to the initial state if that happens.

This work for me:
<script>
$( function() {
$( "#draggable" ).draggable();
$( ".droppable" ).droppable({
drop: function( event, ui ) {
if( $(this) ){
$( "#draggable" ).draggable( "disable" );
}
},
});
} );

jQuery UI - dropped element -> from which div was it dragged

I have a problem with jQuery UI and get some information of a dropped item.
I have three areas on the screen:
<div id="area1"></div>
<div id="area2"></div>
<div id="area3"></div>
In these areas, I put elements which are draggable with jQuery UI.
Now if an element is dropped from one to another area, I will not only get the area number in which the element is dropped to, I also want the area number where the element was dropped before the new drop.
I created a full working example: http://jsbin.com/iyaya3/
There is a blue draggable element and if I drag it from area1 to area2, I want to have the alert message with "dragged from area1 - dropped to area2".
How can this be done?
Best Regards, Tim-.

Hey, I updated your jsbin - http://jsbin.com/iyaya3/3
It works like this:
Take initial parent element's id and save it on draggable using jQuery.data
When dropping it on droppable, update data

I've got two ideas:
1) You can put a class or ID on the elements in each div:
<div id="area1"><node class="from1"></node></div>
<div id="area2"><node class="from2"></node></div>
<div id="area2"><node class="from2"></node></div>
And then test for that when you have the item
2) Write a function to do the clone instead of relying on the drag and drop to do it for you (http://ui-dev.jquery.com/demos/draggable/#option-helper) and then test for the parent and store that (in a singleton outside the scope of the dragger) where you can get it later.
I think I would prefer the first (even if you don't have html access to add these classes, just add it with javascript)

In your draggable setup, add this:
start: function(event,ui){
ui.helper.data('from-id', $(this).parent().attr('id') );
}
This will attach, as data, the ID of the container from which the element is being dragged.
Then, in the droppable, you can have:
alert( 'I was dragged from ' + ui.draggable.data('from-id') );
Here's the updated jsBin.
Edit: The start function creates a closure, so $(this).parent().attr('id') continues to point to the original parent. One solution to this problem (if you wish to keep a start function) is to clear start when the drag stops:
stop: function(event,ui){
ui.helper.draggable({ start: null });
}
This will allow the data methods in the droppable handlers to update the from-id without being immediately reverted to the original value by the start function.
Here's a revised jsBin example.

$(element.draggable).parent().attr('id')) works for me

I removed the duplicated code and solved the problem by saving the previous element id by the data() function.
JS Bin
<script type="text/javascript">
$(document).ready(function() {
$('#area1').append('<div class="shoulddraggable" style="width:100px;height:100px;top:0px;left:0px;background-color:blue;" data-elementid="100"></div>');
$(".shoulddraggable").draggable({
scroll: false,
revert: "invalid",
scope: "items",
});
$(".shoulddraggable").data('previousId', 'area1');
$('.droppable').droppable({
scope: "items",
drop: function(event, ui) {
alert('Previous container id: ' + ui.draggable.data('previousId'));
alert("Element: "+ui.draggable.data("elementid")+" dragged into" + $(this).attr('id'));
ui.draggable.data('previousId', $(this).attr('id'));
}
});
});
</script>
</body>
</html>

jQuery Drag plugin - Prevent dropping of a drag element on the top of another

I uses the jQuery pluins event.drag and event.drop
see a demo (just a reference question is not about restricting movement to a container)
Is it possible to prevent dropping of a drag element on the top of
another element? but it can be dragged over the other.

While you can accomplish what you want with the event.drag/drop script it is also easily done using jquery ui - draggable/droppable.
For the event., you need to return false if it meets yours criteria (or vice versa):
$('#drag1').drop("init",function(){
if ( $( this ).is('#badDiv') )
return false;
})
Here is the jquery ui version, it has a built in accept option in the $().droppable function - it accepts selectors also. This example is reverse of above. The above will let you move anywhere but badDiv, whereas this example below will won't let you move anywhere but the defined droppable:
script:
$("#drag1, #drag2").draggable({
revert: 'invalid'
});
$("#drop").droppable({
accept: '#drag1',
drop: function(event, ui) {
// whatever happens on drop
}
});
html:
<div id="drop" style="width:300px;height:300px;background:blue"></div>
<div id="drag1" style="width:50px;height:50px;background:green"></div>
<div id="drag2" style="width:50px;height:50px;background:yellow"></div>
This creates a big droppable area, but it will only accept the draggable ID of drag1. To see this effect you also need the option in your draggable for revert. This case I set it to invalid so the draggable will slide back to its original position if the drop is not valid.
I'm not sure of your exact application, but maybe this will point you in the right direction of what you're trying to accomplish.
I believe that the sorttables uses a similar setup, but that has more with appending divs and adjusting tables.

You can assign a valid drop target selector in this way.
$('.drag').drag(function( event, dd ){
// move the dragged element
},{ drop:'#drop1' }); // assign drop selector
You can also return some drop event handlers "false"
$('.drop').bind('dropinit drop',function( event, dd ){
if ( $( dd.drag ).is('#drag1') )
return false;
});

jquery droppable accept

Can anyone tell me how I can write a function in accept condition and then how does it finds out that what to accept and what not to accept.
For example, I want to accept div a and div b in accept condition. How can I write I through a function?

If you want the droppable to accept a selection of elements you can do something like this:
$(".droppable").droppable({
accept: function(d) {
if(d.hasClass("foo")||(d.attr("id")=="bar")){
return true;
}
}
});
This droppable will accept elements with the class "foo" or an element with the id "bar"

If I understand your question correctly, you want to conditionally accept the dropped element based on custom code. Aberon's answer is the typical case: you want to allow only certain draggable options to be dropped based on their class, and all others will revert. If that answers your question, then fine.
However, there is a case for having the revert animation happen conditionally based on something more complex than a class match. In my own project, I am using drag-drop to add users to a group. If the dropped user is already in the group, I want the user helper element to revert back. Otherwise, I go ahead with an AJAX action to insert them. This is no substitute for back-end checking, but it's nice visual feedback.
I have looked elsewhere for a simple answer to this. Note to JQuery maintainers: to me, the most straightforward way would be to add some property to the event object in the drop function, like this:
$('.target').droppable({
accept: '.valid'
drop: function(event, ui) {
if(isDropOK() == true) {
// add child here
} else {
event.revert = true;
}
}
});
Sadly that doesn't work. Here's what does "work", though: set the draggable element to always revert, and then hide the helper if the condition is met. You can get a reference to the helper by looking for the only element on the page that has the class ".ui-draggable-dragging". Here's an example, replace "isDropOK()" with your own logic:
$('.valid').draggable({
revert: true,
helper: 'clone',
opacity: 0.5
});
$('.target').droppable({
accept: '.valid'
drop: function(event, ui) {
if(isDropOK() == true) {
$('.ui-draggable-dragging').hide();
// add child here
}
}
});
So to recap, every element will always revert unless you step in on the drop event and manually hide the helper. The revert animation will still happen, but your users won't see it. It's a little hack, but the end result seems to work all right.

According to the Jquery documentation on Selectors.
All draggables that match the selector
will be accepted. If a function is
specified, the function will be called
for each draggable on the page (passed
as the first argument to the
function), to provide a custom filter.
The function should return true if the
draggable should be accepted.
Thus,
$('.selector').droppable({ accept: '.special' });
in their example will only act as if something has been dropped on it if it has the class 'special'. It looks like it can accept any Jquery selector.

In addition to Alex answer which is the best answer I found on this question, I like to add, that if you want to check for matching attributes between droppable and draggable, you can use the keyword this to access the droppable within your accept function. Here is a small example I recently used:
accept : function (draggable) {
var id_group_drop, id_group_drag;
//get the "id_group" stored in a data-attribute of the draggable
id_group_drag = $(draggable).attr("data-id-group");
//get the "id_group" stored in a data-attribute of the droppable
id_group_drop = $(this).parent().attr("data-id-group");
//compare the id_groups, return true if they match or false otherwise
return id_group_drop == id_group_drag;
}
So the draggable is only accepted, when it's id_group (remember, just an example) matches with the id_group of the droppable, otherwise the draggable would be reverted. I think this could be a very common use-case, maybe this will help someone.

This is the solution that I use:
... accept: '#diva,#divb', ...

I've figured out a solution that works based on the condition that no draggable should be placed in a droppable already occupied by another draggable:
$(".placement").droppable({
accept: function(elm) {
// only allow draggables to the placement if there's no other draggable
// in the droppable
if (!$(this).attr('isbusy'))
return true;
},
drop: function(event, ui) {
$(this).attr('isbusy', 'yeap'); // fill key with something
var draggable = $(ui.draggable[0]);
// free the draggable's previous droppable
if (draggable.attr('droppable')) {
$('#' + draggable.attr('droppable')).attr('isbusy', '');
}
// save the new draggable's droppable
draggable.attr('droppable', $(this).attr('id'));
},
});

Instead of using a class as accept, you can just use a function like
and return true if it matches your criteria
$('#mydroppable').droppable(
{
accept: function() { return true; },
drop: function () { alert("Dropped!"); }
});

This is my solution:
var foo = true;
$( ".draggable" ).draggable({
revert: function(){if(foo == true){return true;}else{foo = true;}},
});
$("#droppable").droppable({
activeClass: "ui-state-hover",
hoverClass: "ui-state-active",
drop: function( event, ui ) {
if($this == $that){
foo = true;
alert("this will revert the draggable back to original position");
}else{
foo = false;
alert("this will NOT revert the draggable back to original position");
}
}
});

jQuery: How to stop a helper from being removed if it wasn't successfully dropped

I have a draggable with a custom helper. Sometimes the helper is a clone and sometimes it is the original element.
The problem is that when the helper is the original element and is not dropped on a valid droppable it gets removed. My solution looks like this so far:
in my on_dropped callback I set ui.helper.dropped_on_droppable to true;
In the stop callback of the draggable, I check for that variable and then ... what do I do?
$('.my_draggable').draggable({
stop : function(e, ui) {
if (!ui.helper.dropped_on_droppable) {
/* what do I do here? */
}
},
Is this even the right approach?

Ok, I found a solution! It's ugly and it breaks the 'rules of encapsulation,' but at least it does the job.
Remember this is just for special cases! jQuery can handle its own helper removal just fine. In my case I had a helper that was sometimes the original element and sometimes a clone, so it wasn't always appropriate to delete the helper after reverting.
element.draggable({
stop : function(e, ui) {
/* "dropped_on_droppable" is custom and set in my custom drop method
".moved_draggable" is custom and set in my custom drag method,
to differentiate between the two types of draggables
*/
if (!ui.helper.dropped_on_droppable & ui.helper.hasClass('moved_draggable')) {
/* this is the big hack that breaks encapsulation */
$.ui.ddmanager.current.cancelHelperRemoval = true;
}
},
Warning: this breaks encapsulation and may not be forwards compatible

I might be missing something here, but is it not simply a case of adding
revert: "invalid"
to the options of the draggable if the draggable is of an original element, not a clone?

I use a custom helper that aggregates multiple-selection draggables into a single div. This does not seem to jive with the revert functionality so I came up with this scheme. The elements are manually appended back to the original parent which I keep track of via .data().
.draggable({
helper: function() {
var div = $(document.createElement('div'))
.data('lastParent', $(this).parent());
return div;
},
start: function() {
//... add multiple selection items to the helper..
},
stop: function(event,ui) {
$( $(ui.helper).data('lastParent') ).append( $(ui.helper).children() );
}
}
This approach does lose out on the pretty animation, but it may be useful to you or someone else with this issue.