if my server side script, that handles datatable requests (also update request), needs to give back any error state - i.E. Server side validation error - how could i handle that? Is there any datatable event where i could have a look into the response text / json?
For data saving operations you can use onAfterUpdate event
http://docs.webix.com/api__dataprocessor_onafter_event.html
It gives access to response json, that can contain custom error attributes
As for common error handling there is a onLoadError event, it can be used on any component, including dataprocessor for saving event, or “webix” object to handle all ajax errors on the page.
http://docs.webix.com/api__dataprocessor_onloaderror_event.html