Validation is a mechanism to ensure that the process flow created in the Graph Canvas is correct as per the BPMN standard and Connect Server. If the process flow is incorrect, an error message is displayed in the Alerts Panel.
In the above figure, you can see that Start Event is not connected with Source activity and has no outgoing sequence flow and Source activity has no incoming sequence flow. The validation message is displayed in the Alerts option of the toolbar.
There are two categories of validations:
- BPMN Server Specific Validation: This includes Connect Server validations, for example, File Target has no input source stream. This is displayed as "BPMNServer" in the Category column of Alerts option.
- BPMN Specific Validation: This includes BPMN specific validations, for example, end event cannot have outgoing sequence flow. This is displayed as "BPMN" in the Category column of Alerts option.
Validation messages are further divided into two types:
- Error: These are displayed in the Alerts Panel with type (
) along with error message and the corresponding user action is reverted if possible. If revert action takes place successfully then a warning message is displayed explaining the reason of revert operation. For example, start event cannot have incoming sequence flow, hence removed. - Warning: These are displayed the Errors Panel with type (
) and the corresponding warning message is displayed. For example, start event has no outgoing sequence flow.