how to revert position of a jquery UI draggable based on condition

Question

I have an element which is draggable and an element which is droppable. Once the dragged item is dropped on the dropzone I am trying to execute the following jquery psuedo code:

if(draggedelement == value){  $(draggedelement).hide();  } else{  $(draggedelement).revert();  } 

where the revert() function moves the dragged item back to its original postion.

How would one accomplish this?

P.S. I am aware of the draggable 'revert' option, however this only activates if the dragged item does not make it to the dropzone.

Answer 1

There are some built-in options for this, on your .draggable(), set the revert option to 'invalid', and it'll go back if it wasn't successfully dropped onto a droppable, like this:

$("#draggable").draggable({ revert: 'invalid' }); 

Then in your .droppable() set what's valid for a drop using the accept option, for example:

$("#droppable").droppable({ accept: '#draggable' });​ 

Anything not matching this selector gets reset when you let go, you can see a full demo here. The accept option also takes a function if you need filtering a selector can't provide, like this:

$("#droppable").droppable({    accept: function(dropElem) {     //dropElem was the dropped element, return true or false to accept/refuse it   } });​