Create link issue between groups

Gantt
#1

Hello. When we create link between operation grp as here , but when one grp dont have child, the target grp is not changing its start time. I want it to change

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Thanks

#2

Hello,
The group tasks are virtual tasks with the project type. Projects depend on the dates of their children. So, when you create a link with a project task, Gantt creates a virtual link with its child tasks. Because of that, there is no way to move project tasks without links:
https://snippet.dhtmlx.com/33eku0nl

In the future, the dev team will add a way to set manual dates for the project tasks.
For now, you need to manually convert the group tasks to regular tasks. And you can make them look like project tasks:

gantt.eachTask(function (task) {
    if (task.$virtual && !gantt.hasChild(task.id)) {
        task.type = gantt.config.types.task
        task.fake_task = true;
        gantt.updateTask(task.id);
    }
});

Here is an example:
https://snippet.dhtmlx.com/2apizlen

Also, it is not recommended to create links with virtual tasks. Because as soon as you change the group mode or reset grouping, the virtual tasks will be removed. And it means that next time you group tasks, you won’t see the link. The link itself will remain, but as it expects the old virtual task, Gantt won’t render it. So, if you need to create links with the group tasks, you will need to implement a custom solution to keep the links.

#3

Hello,
The dev team added the feature that allows adding custom dates to the project tasks:
https://docs.dhtmlx.com/gantt/desktop__custom_projects_dates.html

You can see how it works in the following sample:
https://docs.dhtmlx.com/gantt/samples/04_customization/25_project_dates.html