Dragging Project (consisting multiple tasks) data inaccuracy issue (URGENT)

Gantt
#1

Hi All,

I found a very serious issue on scaling and dragging.
The bug i found is data inaccurate/incorrect while dragging project level task at large scale (for example, in Year scale) (when the task bar is practically small when the scale is large).

I have a code snippet to trigger the error i encountered.

Information for the code snippet:-
-10 generated tasks under 1 project.

  • Each task continues after another. (Current Task Start Time is Previous Task End Time)
  • Each generated task duration is 48 hours.

Steps to retrigger the bug I found:-

  1. Open https://snippet.dhtmlx.com/f0b9935f1(Validate that each task continues after another)
  2. Change to Year Scale using the radio box on top.
  3. Now, you will see all the tasks are very small under the project.
  4. Check the total duration of the project. (1 task is 48 hours, 10 tasks means 480 hours.)
  5. Drag the project to left or right, and check out on the total duration.
  6. Switch to Day Scale
  7. Check the tasks start date time.

Based on understanding, dragging on the project level will not change the duration. But based on the steps 1 - 5, the total duration of the project changes.
Also, in step 6 - 7 , If you see clearly, each task is not continue one after another, and possible that tasks overlap with each other also (If the discoutinuotion is not clear, feel free to repeat step 2 - 5 until bigger difference in duration than 480 hours), where the start time of the tasks changes.

May I know is there anyone facing this issue as well? And how can I fix this ?

Thanks In Advanced!

#2

Hello,
Thank you for reporting about the issue.
We have that bug in our tracker, but the dev team has not started fixing it yet.
And you provided the additional details.
Looks like, the taskbar width is different, although the tasks have the same duration. And the position in the chart is not always precise.
I suspect it is related to rounding (the cell width is too small, so Gantt rounds the dates).
I cannot give you an ETA when the bug is fixed, but I will notify you when the fix is ready.

Now, as a workaround, you can add the day subscale in the year view and increase the minimal timeline cell width so that Gantt will round the values more precisely:

gantt.config.min_column_width = 30;
gantt.config.subscales = [
	{unit: "month", step: 1, date: "%M"},
     	{unit: "day", step: 1, date: "%j, %D"}
];

http://snippet.dhtmlx.com/07dbd3780

#3

Hi,

Thanks for acknowledging the bug.
Hopefully the bug is fixed as fast as possible and hoping to get an update for this from the team as fast as possible as well!

Thanks.

#4

Hi,

May I know is there any updates on this ?

Thanks!

#5

Hello,
The dev team has not started fixing the bug yet.
I still cannot give you an ETA, but I will notify you when the fix is ready.

#6

Hello,
The dev team fixed the bug with the drag_project functionality. Now, if you drag a project task in the month scale, it shouldn’t affect the duration of the project task or its subtasks. Also, the tasks should keep the distance between them:
https://docs.dhtmlx.com/gantt/whatsnew.html#719

You can check how it works in the following snippets:
http://snippet.dhtmlx.com/5/c3c4d0977
https://snippet.dhtmlx.com/5/913cd8462