OnRowDragEnd returns an invalid target dragging down a row

Gantt
#1

Hi,

Using the demo file “02_branch_ordering.html” from dhtmlxGantt_v2.1.0_ent to demonstrate this issue.

If you drag “Task #2.1” downwards over “Task #2.2” with the intention that they should swap order, the target value returned in function onRowDragEnd is actually the Id of task “Task #2.3”.

Code to show Drag & drop details

gantt.attachEvent(“onRowDragEnd”, function(id, target) {

		 	if (target)
		 	{				 					 				 	
			 	var updatenodes = [];
			 				 	
			 	var item 		= gantt.getTask(id);
			 	var itemtarget 	= gantt.getTask(target);
			 											
				console.log(item)
				console.log(itemtarget)
		 	}
		});

Is their a patch to address this issue ?

Thanks
Kevin

#2

Please try to use the attached js file instead of the original one
This is dev. version with patch applied.
dhtmlxgantt-dfix.zip (39.3 KB)

#3

Hi,

The file attached to the previous post “dhtmlxgantt-dfix.zip” has JavaScript error “id is undefined” when creating a relationships between tasks.

Kevin

#4

Sorry for inconvenience ( that is dev. version, it passes the main tests but still can have some problems )

Updated file is attached.
dhtmlxgantt-fix6.zip (39.3 KB)

#5

Hi,
I am using “dhtmlx-gantt”: “^7.0.4” and I’m still facing the same problem.
It works fine when I drag task from bottom to top but it return the one position down task when I drag from top to bottom. If I drag task 1 to task 2, the target returns the task 3 id. Is there any solution?

#6

Hello @Mohaimanul_Islam,

This behavior occurs in the scenario when the dragged task goes just after the target task, which occurs only with replacing the last task in a chart. In this case, the target returns in the format:
next:targetId(string).

You can read about this behavior by the following link:
https://docs.dhtmlx.com/gantt/desktop__server_side.html#storingtheorderoftasks

In this case, you can get the target id with the following code fragment:

// get id of adjacent task and check whether updated task should go before or after it
  if(typeof(target) === "string"){
    targetTaskId  = target.substr("next:".length);
    nextTask = true;
  } else {
    targetTaskId  = target;
    nextTask = false;
  }

Here is a demo:
http://snippet.dhtmlx.com/5/f41b0d47d

Also, I noticed that this behavior doesn’t mention in the onRowDragEnd topic:
https://docs.dhtmlx.com/gantt/api__gantt_onrowdragend_event.html
I sent a report to our tech writers and the documentation will be updated ASAP.

ps. Please, do not duplicate the same question in different topics, thanks.