I need to add a custom button and related click event functionality to a standard fiori application. I was able to add a custom view extenuation and add the button to display in the extension project.
My issue is how to add controller level functionality for the click event. How can I write a custom controller level extension for a new function. So that I can implement the click event functionality in the extension project. Should I extent the controller.js. in the extension project. But I feel it is unnecessary since I need to implement only the click event functionality in the extention project. Is there any other way to do it.