Validation

The DevExtreme JavaScript Gantt component allows you to validate relationships between tasks and handle errors. Set the enableDependencyValidation property to true to enable task validation.

The Gantt supports the following dependency validation rules:

• Finish to Start (FS) - A successor task's start point should be equal or later than the preceding task's end point.
• Start to Start (SS) - A successor task's start point should be equal or later than the preceding task's start point.
• Finish to Finish (FF) - A successor task's end point should be equal or later than the preceding task's end point.
• Start to Finish (SF) - A successor task's end point should be equal or later than a preceding task's start point.

The Gantt also has the autoUpdateParentTasks property that enables validation for parent-child relationship:

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