Several plugins are available which provide functions to make interacting with the iOS keyboard a bit easier and include events to indicate when the keyboard will be shown or hidden.
The cordova-plugin-keyboard plugin adds functionality to customize and control the device keyboard, including several events that are triggered when the keyboard is shown or hidden.
See NPM: cordova-plugin-keyboard for complete documentation.
The cordova-plugin-ionic-keyboard provides functionality to customize and control the device keyboard and is designed to work with the cordova-plugin-ionic-webview.
See NMP: cordova-plugin-ionic-keyboard for complete documentation.