You can validate new data before saving it to the data source. The GanttControl raises events that allow you to validate modified cells and nodes. You can prohibit saving invalid data to the data source and indicate any errors.
The GanttControl is a TreeList (and GridControl) descendant which means you can validate the user input in the treelist area in the same way as the GridControl. Refer to the Input Validation topic for more information.
Validate Data Edits in Gantt Area
The validation functionality helps you keep data consistent and valid. For example, an end user is not allowed to connect two tasks in the following circumstances:
- the two tasks are a summary task and one of its child tasks
- the successor task and the predecessor task are the same
- the connection already exists
- creating a connector causes a cyclic connection between the tasks
The image below demonstrates how the GanttControl prevents an end user from creating a cyclic task connection and creating a connection that already exists.
When the AllowValidatePredecessorLinks property is set to true, the GanttControl marks the invalid connectors in red.