Validation

The DevExpress ASP.NET Gantt control (ASPxGantt) allows you to validate relationships between tasks and handle errors. Set the EnableDependencyValidation property to true to enable task validation.

The Gantt control supports the following dependency validation rules:

• Finish to Start (FS) - A successor task's start point should equal the preceding task's end point.
• Start to Start (SS) - Successor and predecessor tasks should begin at the same time.
• Finish to Finish (FF) - Successor and predecessor tasks should end at the same time.
• Start to Finish (SF) - A successor task's end point should equal a preceding task's start point.

Dependency rules specify that you can move only the successor to create or change the gap between tasks. Set the EnablePredecessorGap property to true to increase/decrease the gap between the tasks with a predecessor.

The Gantt control also has the AutoUpdateParentTasks property that enables validation for parent&child relationships:

• A parent task's duration equals a summary duration of its child tasks.
• A parent task and its first child starts at the same time.
• A parent task and its last child ends at the same time.
• A parent task's progress is a summary progress of its child tasks.

The control processes changes in task values before they are saved to a database. The control displays a popup window with a list of available actions if an error can be handled in several ways.