Understanding Compose (Android Dev Summit '19) 

Really awesome video, I can't wait to see how Compose progresses. Playing around with it during the conference was very promising though. I think after I get through the rest of my Modern Android Development video series I'll start creating one for future looking things (such as Compose) 😁

Google io 2021 we are introducing redux-compose and redux-coroutines for communication between different layers

Google is trying to migrate layout XMLs to be like Flutter?

So it's basically like React Components now, which is a good thing!

awesome share for go deep into ui development construct.

Very helpful video, compose makes much more sense after understanding this.

You had me at declarative ui

Well, you convinced me!

@9:20 When declaring Declarative vs Imperative, there is a minor bug in the imperative code (if no paper, remove paper). But, more importantly, the declarative code doesn't even handle the edge case of displaying the text "99+". It wouldn't add much complexity to cover that edge case in the declarative code (Badge(text=if(fire) "99+" else "$count") but it feels dishonest to ignore it and benefit from the code looking "cleaner".

Does this mean that we will go away from context and reference of the activity to the views ?

Notes for myself - Declarative vs Imperative: 8:40 - Composition: 11:00 - What @composable actually does? 18:19

I didn't understand yet what the "+" before the "hooks" mean.

20:20 this is why you learn algorithms when interviewing for FAANG

If I understand this properly, it's able to memorize states of your UI and change views only if the state changes. Seems powerful, but the usage is still confusing. First, I didn't get what the '+' operator means. Next, it was told that "a composable function can be called from only within a composable function", so, how can one use this with libraries like, for example, RxJava? In the presentation there is a call to getData() function (25:42), which either returns the prepared data or returns null, if the data is not ready yet. And thus, there must be a way to re-call the composable App function when the data is ready. How is this handled? Does the module which provides the data call the UI module's App function? - But that's a total snafu because it's typically the UI which calls the data module's methods. So, after watching 2 videos from Google IO's about composable UI I'm left with a huge misunderstanding.

Great

Welcome Flutter!

So it's react and that's cool.

this is a huge game changer

great!from china

I think at 9:38 Last second if statement is wrong

im lost since minute 16, the recomposition. Compose is simply an implementation of React.js's Component. Why not use the same name, it is good for developer :D

Betting on Kotlin takes its toll. Requiring changes to a compiler for such things is ridiculous. But as the CTO of Jetbrains often reiterates, he doesn't see use cases for compile time functions (aka real macros). Well this here is one of 'em.

Second comment from India, first one from 50 ft under the ground.

9:32 , that code is wrong.

SteadFast Updated

For me is total no-sense, I think they will provide this as an external library to integrate in projects but we still be able to use XML layouts, then this approach for me has so much lacks. For example how this approach would works if I want to build a custom animated drawable? Then, how to extend a Button() to make a custom view? Then how to see layout changes in real time while creating the view inside the editor itself? It should let me see a preview of what the final result is I will prefer XML so far, it is much clear then with dataBinding it is the top of the top

Is this still a thing? Android associate certification doesn't cover this

val count = +state { 0 } :| What does it mean?!!

So, if you make Kotlin like Flutter, then why shouldn't I use Flutter in the first place?

it is much more convenient to build ui in android than in iOS，but experience in iOS is better.

First Comment from Star-Link

Can anyone tell me that how can I improve my coding skill without any cost?... . please

First comment from China

It's like react but for Android

Welcome Kotlin to the flutter /react world what took you so long kkk

Comment from ..... See dp 😀

First Comment from Swaziland

Sample app of Compose on github.com/android github.com/android/compose-samples

9:35 alright so if (count > 0 && !hasPaper()) remove the paper anyway. I guess we're not getting any paper boys. Maybe this mistake was to show us how easily bugs are introduced ;)

I do not understand exact reasons of introducing compose . Even XML layout are also declarative. Isn't ? we leave out exact position and make that to be more generic to fit all type of devices .

Did the flutter team help with this

9:26 and 9:46 are terrible examples. The non-compose code at 9:26 is intentionally written badly. You could write it in a very similar manner to the compose example. And the compose example is terrible because it's the opposite of separating concerns. The first 5 minutes is talk about separating concerns and then you give an example with business logic and ui mixed together.

First comment from Mexico 😈🥰

First comment from Kenya

Can’t we just have Swift on Android already and make app devs lives easier

It's flutter kotlin version

First comment from India

lies. you still have to think about it because of rules and behaviors of recomposition.

I really don't like this flutter version of the Android. We have already XML which manages layouts amazingly amd also separates the UI logic, then why bringing this one, a component driven programming like flutter/react does.