iOS keyboard extensions use the native UITextDocumentProxy to integrate with the currently active application. However, if you have a text field in your keyboard, you need to find a way to route the text to that text field instead of the active application.

KeyboardKit adds ways to make text routing easier. KeyboardInputViewController has a custom textInputProxy that can be set to route text from the original proxy to any other text field.

KeyboardKit Pro unlocks even more capabilities, such as a text fields that automatically register and resign as the main proxy. Information about Pro features can be found at the end of this article.

How does text routing work?

UIInputController has a textDocumentProxy, which is how a keyboard is meant to integrate with the currently active app.

However, there may come a time when you have to type into a text field inside the keyboard instead of sending the text to the main app, for instance to implement in-keyboard search.

For this to work, you need a way to route the text so it stays within your keyboard, instead of being sent to the main app. KeyboardKit makes this kind of text routing easy to implement.

How to route text with KeyboardKit

KeyboardKit has a TextInputProxy that can be used to route text to a custom text input, such as a text field within the keyboard extension.

KeyboardInputViewController then has a textInputProxy that can be set to replace textDocumentProxy as the main text document proxy.

Setting textInputProxy will cause any text you type into the keyboard to be sent to that proxy instead of the original proxy. Just set the custom proxy to nil to start routing text back to the main app.

You can always access the original text document proxy with mainTextDocumentProxy.

👑 Pro features

KeyboardKit Pro unlocks text input views that automatically register and unregister themselves as the main text input proxy when they receive and lose focus:

• KeyboardTextField wraps a UITextField and can be used for single-line text inputs.
• KeyboardTextView wraps a UITextView and can be used for multi-line text inputs.

Both views also support SwiftUI FocusState and have a focused view modifier that lets you provide a custom done button that slides in when the view is focused.

You can also let any UIResponder & UITextInput implement the KeyboardInputComponent protocol, then call its functions to make it register and unregister as the main text document proxy.

You can also let any SwiftUI view implement the KeyboardInputView protocol to apply a focused state, together with a done button that appears when the text field has focus.

Documentation

The information on this page is shortened to be easier to overview. For more information about this feature, code samples, etc., please see the online documentation.