问题

What I have:

I have a draggable div with a revert parameter set as "invalid".

What I need:

When the revert occurs I want to trigger a CSS change to another element.

The problem:

"revert" is parameter rather than an event so I'm experiencing great difficulty in triggering the required CSS change when the revert occurs.

My code:

$('#peg_icon').draggable({
    revert: 'invalid',
    scroll: false,
    stack: "#peg_icon",
    drag: function(event, ui) {
        $('#peg_icon').css('background-image','url(images/peg-icon-when-dragged.png)');
    }
});

What I've tried:

I've unsuccessfully attempted using "revert" as an event:

revert: function(event, ui) {
    $('#peg_icon').css('background-image','url(images/peg-icon-default.png)');
},

I've also unnsuccesfully tried to get the revert paramater to take this function:

function(socketObj)
  {
     //if false then no socket object drop occurred.
     if(socketObj === false)
     {
        //revert the peg by returning true
        $('#peg_icon').css('background-image','url(images/peg-icon-default.png)');
        return true;
     }
     else
     {
        //return false so that the peg does not revert
        return false;
     }
  }

Context:

I'm dragging a div that when dragged, the background-image changes and when the drag reverts, the background-image is restored to its original state.

My question:

How do I trigger a CSS change to another element when revert occurs on a drag?

回答1:

It turns out that revert can accept a method. See this for a complete example: http://jsfiddle.net/mori57/Xpscw/

Specifically:

$(function() {
    $("#ducky").draggable({
        revert: function(is_valid_drop){
            console.log("is_valid_drop = " + is_valid_drop);
            // when you're done, you need to remove the "dragging" class
            // and yes, I'm sure this can be refactored better, but I'm 
            // out of time for today! :)
            if(!is_valid_drop){
               console.log("revert triggered");
                $(".pond").addClass("green");
                $(this).removeClass("inmotion");
               return true;
            } else {
                $(".pond").removeClass("green");
                $(this).removeClass("inmotion");
            }
        },
        drag: function(){
            // as you drag, add your "dragging" class, like so:
            $(this).addClass("inmotion");
        }
    });
    $("#boat").droppable({
      drop: function( event, ui ) {
        $(this)
          .addClass("ui-state-highlight");
      }
    });
  });

Hope this helps... I'm guessing that whatever you were trying to modify was the issue, not the attempt to use revert with a function call. Take a look again at what CSS you were trying to set, and see if maybe your issue was in there.

回答2:

You want to do something like this:

 $('#peg_icon').draggable({
        revert: function (socketObj) {
        if (socketObj === true) {
            // success
            return false;
        }
        else {
            // reverting
            return true;
        }
    },
        scroll: false,
        stack: "#peg_icon",
        drag: function(event, ui) {
            $('#peg_icon').css('background-image','url(images/peg-icon-when-dragged.png)');
        }
    });

DEMO: http://jsfiddle.net/yTMwu/35/

Hope this helps!

来源：https://stackoverflow.com/questions/14571919/adding-a-function-to-jquery-draggable-revert-event

标签

jquery-ui

revert

jquery-draggable

Adding a function to jQuery draggable revert “event”

问题