How to control the traffic-light status display on a node

I would like to know how I can control the traffic-light status on a new node.

My personal node has not any input port and requires an obligatory configuration (the absolute path of a directory).

But when I put my node on the KNIME workflow, its traffic-light status is amber, wheareas my node is not ready to be executed because the user has not entered a directory absolute path.

So the user can execute my node, which is not ready and so produces errors.

Can you please give me the methode or class which this handle this?



You need to implement the configure-method in such a way that it checks if a path has been provided. If not, throw an exception and the traffic light will be red. configure will be called each time the user changes the settings and if the node is dropped on the workflow the first time.

Thanks, it works.