Support Node selection (#25)

Summary: Lexical web supports multiple kinds of selection, including RangeSelection (works off text ranges) and NodeSelection (where some nodes are explicitly selected; usually used for selecting decorator nodes).

This diff adds the groundwork for node selections in Lexical iOS.

Pull Request resolved: https://github.com/facebook/lexical-ios/pull/25

Test Plan: Testing was mainly focussed on avoiding regressions in RangeSelection. All unit tests pass, and I’ve done some testing in the playground on the simulator.

I haven’t written any feature that uses NodeSelection yet (coming soon), so NodeSelection itself has not had much testing. I don’t think this is a huge problem yet; we can iterate upon it as the first feature using it is built.

Reviewed By: zurfyx

Differential Revision: D46267551

Pulled By: amyworrall

fbshipit-source-id: 3c15ab0adef7ee1b9fe5b4a03bb913fe7ba4d15b

Lexical iOS

An extensible text editor/renderer written in Swift, built on top of TextKit, and sharing a philosophy and API with Lexical JavaScript.

Status

Lexical iOS is used in multiple apps at Meta, including rendering feed posts that contain inline images in Workplace iOS.

As of March 2023, the date of our initial open source release, Lexical iOS should be treated as an unsupported preview version. We have not established a version numbering or release cadence yet; it is expected our first ‘release’ will be numbered 0.1.

Playground

We have a sample playground app demonstrating some of Lexical’s features:

Screenshot of playground app

The playground app contains the code for a rich text toolbar. While this is not specifically a reusable toolbar that you can drop straight into your projects, its code should provide a good starting point for you to customise.

This playground app is very new, and many more features will come in time!

Requirements

Lexical iOS is written in Swift, and targets iOS 13 and above.

Building Lexical

We provide a Swift package file that is sufficient to build Lexical core. Add this as a dependency of your app to use Lexical.

The plugins included in this repository do not yet have package files. (This is because we use a different build system internally at Meta. Adding these would be an easy PR if you want to start contributing to Lexical!)

Using Lexical in your app

For editable text with Lexical, instantiate a LexicalView. To configure it with plugins and a theme, you can create an EditorConfig to pass in to the LexicalView‘s initialiser.

To programatically work with the data within your LexicalView, you need access to the Editor. You can then call editor.update {}, and inside that closure you can use the Lexical API.

For more information, see the documentation.

Full documentation

Read the Lexical iOS documentation.

Join the Lexical community

Feel free to join us at our Discord server, where you can talk with the Lexical team and other users.

See the CONTRIBUTING file for how to help out.

Tests

Lexical has a suite of unit tests, in XCTest format, which can be run from within Xcode. We do not currently have any end-to-end tests.

License

Lexical is MIT licensed.