Dependent task moving incorrectly

Gantt
#1

I’ve got a problem where a start_to_finish dependency is incorrectly being calculated when I resize a task and I can’t quite figure out what’s going on. I’ve put together an example that isn’t working:

http://snippet.dhtmlx.com/5/c7f889df5

The example has a very basic structure

  • Task 1
  • Task 2
    ---- Task 2.1

There is one link between Task 2.1 and Task 1. The link has a lag of 1 day.

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  • If I move Task 2.1 forwards or backwards, Task 1 correctly moves forwards or backwards accordingly
  • If I resize Task 2.1 start date, Task 1 does not get moved at all (incorrect given the dependency type)

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  • If I resize Task 2.1 end date, Task 1 does move even though it shouldn’t

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It seems like there’s something going wrong when resizing tasks. I’ve tried changing the constraint type and various other configuration options but I’ve not had any luck

#2

Hello,
It seems to be related to the type of the link’s type property.
Gantt expects the String type:

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https://docs.dhtmlx.com/gantt/desktop__loading.html#dataproperties

In your case, it is Number, so, there is no guarantee that it will work correctly.

To use the Number type, you need to modify the gantt.config.links parameter:
https://docs.dhtmlx.com/gantt/api__gantt_links_config.html
Here is the updated snippet with the fixed link type:
http://snippet.dhtmlx.com/5/aa5fd8f50

#3

Facepalm! Thanks for that, appears to be working correctly now. I wonder if it would be worth the gantt spitting out warning about things like this. I never would have found that or even considered that was an issue