How can I create custom events in GoJs? Can you also provide some examples for custom events?
First, I hope you have read http://www.gojs.net/latest/intro/events.html to get an overview of all of the kinds of events that GoJS supports.
If you are looking to implement an event handler, there are many examples of declaring a Diagram DiagramEvent listener or a Model Changed listener in the samples. There are also many examples of event handlers that are function values of GraphObject or Tool properties.