Declarative UI patterns (Google I/O'19)

Explore how reactive and declarative paradigms can be applied to Android UI development, making it easier for developers to integrate these patterns into their Android apps with Kotlin.

Watch more #io19 here:

Speaker(s): Jim Sproch, Adam Powell, Romain Guy

T29485 event: Google I/O 2019; re_ty: Publish; product: Android - Languages; fullname: Adam Powell, Romain Guy;

[lone.wof]

*Romain* is the *best speaker @Google*, he doesn't hesitate to even talk about Google's/their inefficiency or mistakes and he is also humorous... We want more lectures and videos from him...

[ninjaever_]

mark~
history of android UI
5:50 refactor UI

14:14 jetpack compose!
18:20
23:45 data flow
26:35
29:50 recap


30:50

[AdrianTache]

This looks a lot like React Components and I think I like it!

[ThomasGallinari]

This is truly awesome, very much like Flutter but for native Android with Kotlin! Can't wait for a stable version!

[Masterrunescapeer]

As someone who left Android development mid 2015, this has tempted me to come back as it looks a lot easier to write and manage the UI.
Since 2015 have basically only used web apps, since most stuff needed to be cross-platform.

[YuriyKulikov]

The most exciting change in Android since Kotlin support announcement!

[ankurg_]

I always wondered why scattering all UI code was "best practice". Great to know this will fix it. It would take a year or so for this I guess.

[Dhruvam]

This is the best part. Declarative UI ❤️
Why did they not do it earlier? 😍😍

[marta_na_moto]

Every time he says "so it turns into something very simple" I get goosebumps ;).. Yeah android and "simple" :))

[abhico]

this makes me cry!
all the pain through the years.. no more!

[atexit]

Isn't reassigning mutable variables in a data class inside the function a side effect that makes the functions non-pure?

[MichalBacik]

Next big thing is coming! It looks like time to start playing with this.

[tombaker]

It's just what Flutter is doing even with the "Apply Changes" hot reload feature. I thought I heard it will also bypass platform widgets and draw the view to the screen directly, very like Flutter.

[ldelafuente]

They are paving the way for Android Developers to become Flutter Developers because of Fuchsia!

[FredoCorleone]

Speaking of imperative vs declarative I don't see why one approach would exclude the other.
I like to be declarative at times, for instance when dealing with pipelines and lists, and to be imperative when things get hard so that I'm not the only person who can touch that code.
It feels like the old battle between OOP and functional programming. I've noticed that different part of an app are better written in different styles, the inner core of an app, where data is, is better written in functional style thanks to the predictability of pure functions, while the outer shell of an app, where views and components are is very well written in OOP.

[mikhailbabenkov]

Android Transition/Migration to Flutter

[meridiansoftware]

Can't wait to do the transition! 🔥

[kenyakking]

How you use Styles with this? Styles were useful for things like white labeling and different device size support..

[FredoCorleone]

I don't necessarily like the fact every state is managed in a single place like a datastore of sort, I like the Angular approach with services in which every service owns and manages its own state. It's more modular. And I also like to have some state into components sometimes. My components are usually stateful for things like filtering of lists and pagination... For top-level variables such as lists of data I like to have injectable services manage that. So my components are both stateful from an angle and stateless from another. I think this approach is more flexible and feels more organic.

[BoxingHacker]

So are they planning to replace XML, that's what I want to know....