iOS keyboard extensions use the native UITextDocumentProxy to integrate with the currently active application. It lets you insert and delete text, get the selected text, move the input cursor, etc.

The native proxy APIs are however very limited, which makes it hard to get detailed information and perform many standard keyboard operations.

KeyboardKit adds a bunch of proxy extension to make things easier. KeyboardInputViewController also has a custom textDocumentProxy property that lets you do more than with the native proxy.

KeyboardKit Pro adds even more proxy capabilities, such as the ability to read the full document context. Information about Pro features can be found at the end of this article.

Proxy namespace

KeyboardKit has a Proxy namespace that contains proxy-related types. For now, this namespace will only contain types when it’s part of the KeyboardKit Pro build.

Extensions

Since UITextDocumentProxy extensions are not included in the generated documentation, here is a list of extensions that you get access to by simply importing KeyboardKit into your project:

Autocomplete

• hasAutocompleteInsertedSpace
• hasAutocompleteRemovedSpace
• insertAutocompleteSuggestion(_:tryInsertSpace:)
• tryInsertSpaceAfterAutocomplete()
• tryReinsertAutocompleteRemovedSpace()
• tryRemoveAutocompleteInsertedSpace

Content

• documentContext
• isReadingFullDocumentContext

Delete

• deleteBackward(range:)
• deleteBackward(times:)

Quotation

• hasUnclosedQuotationBeforeInput(for:)
• hasUnclosedAlternateQuotationBeforeInput(for:)
• preferredQuotationReplacement(whenInserting:for:)

Sentences

• isCursorAtNewSentence
• isCursorAtNewSentenceWithTrailingWhitespace
• sentenceBeforeInput
• sentenceDelimiters
• endSentence()

Words

• currentWord
• currentWordPreCursorPart
• currentWordPostCursorPart
• hasCurrentWord
• isCursorAtNewWord
• isCursorAtTheEndOfTheCurrentWord
• wordBeforeInput
• replaceCurrentWord(with replacement: String)

👑 Pro features

KeyboardKit Pro unlocks additional text document proxy features when you register a valid license.

Read the full document context

As you may have noticed, the proxy’s documentContextproperties don’t return all text before and after the input cursor. Any new paragraph may at any time stop the proxy from reading more content.

This makes it hard to perform more complex operations, such as proofreading or spellchecking a document, provide AI-based suggestions, etc.

KeyboardKit Pro therefore unlocks additional proxy extensions that let you read all text from the text document proxy. Just use the fullDocumentContext alternatives instead of the documentContext ones.

These functions read the full document by moving the input cursor to get access to more text. It’s not a fail-safe operation, but has been tweaked to provide as accurate results as possible.

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.