does someone know a way to extend the alert view controller?
There is already a registered bug regarding this issue: https://portal.sugarondemand.com/index.php#supp_Bugs/bf747ba0-04db-11e7-9c6a-d4bed9b70c64
Taking a look at the code (Sugar 10.0.2), the problematic point seems to be the init function in sidecar/src/view/alert.js. There it does look up a series of properties in the ViewManager to find the controller class. One example:
ViewManager.views[Utils.capitalize(SUGAR.App.config.platform) + 'AlertView'];
So unfortunately it does not additionally check for ... + 'CustomAlertView' which would probably solve the issue (quick test via js debugger).
Also i don't see a way to modify/extend/hookup the sidecar/src/view/alert.js or sidecar/src/view/alert-view.js