Talk im Park #4: Understanding Declarative UI by Pascal Welsch

Yesterday we enjoyed the 4th meetup of the Cologne based “Talk im Park”. Pascal Welsch, Google Developer Expert for Flutter, talked about „Understanding Declarative UI – The hype of React, SwiftUI, Flutter and Jetpack Compose“. For everyone, who couldn’t attend: Here you find more information and the video recording.

From imperative to declarative UI

SwiftUI and Jetpack Compose are the latest additions to native iOS and Android development. Both are UI frameworks which feature a declarative style, similar to React and Flutter.

The transition from imperative to declarative UI is huge. It requires a mindset change! Instead of mutating individual widgets you have to define states and render them. Which first might seem like a weakness and way too much boilerplate code is the biggest strength of that design.

The old, imperative way of writing user interfaces is still used in millions of apps. Your codebase is most likely one of them! This talk will show you a migration path to prepare your apps for declarative UIs until SwiftUI and Jetpack Compose become stable.

Although all those frameworks let you define UIs in a declarative way, there are huge differences in how they work internally. It’s not fair to compare them, since they are designed for different platforms. But this doesn’t mean interesting facts and differences in their implementation can’t be pointed out.

More about Pascal Welsch

Pascal is Google Developer Expert for Flutter with a strong Android background. He recently made the transition becoming a full-time Freelancer for Flutter, delivering stunning user interfaces to audiences on all platforms. In his spare time, Pascal publishes open-source libraries talks on conferences and shoots photos for his cats Instagram account. https://www.youtube.com/watch?v=zaSn_qA7Nb4&t=4s