Announcing Flutter Release Preview 1(medium.com) |
Announcing Flutter Release Preview 1(medium.com) |
This announcement of preview 1 is coming at a great time as I am launching my first app on iOS and Android next week.
I have a project that will require a WebView in the app.
Also I downloaded Flutter a while back and noticed a lot of buggy / unintuitive behavior with their TextViews (multi-line specifically) such as with copying and pasting, selecting text, etc.
Do you know whether these components have matured?
Looks rather hacky.
(Overall it was still super worth it to use flutter at the time)
How does it handle native APIs? Like React-Native (you have to write bridges in ObjC/Java) or like NativeScript (you can simply access all native APIs via JS)
I wish there was:
1. A good Kotlin language server (unlikely, as the company behind the language is an IDE company).
2. A good reactive Kotlin GUI library (meaning, with the ergonomics of Flutter (as in, I don't have to work with Fragments and their lifecycles, just use views)).
3. A good JVM interpreter (to speed up Kotlin/Java compilation)
[1]. No I don't use Flutter to "write two apps for the price of one", as most (of my) apps are just a front-end over a back-end server, so they don't have any special logic worth saving between iOS and Android. I just find Flutter easier to work with relative to Android.
Based on the issues they've had with React Native [1] I believe they would've had a better experience with Dart and Flutter which also has a fast iterative dev experience with a productive language that lets you build both iOS and Android Apps from a single code-base. But in contrast to RN, Dart 2 is statically typed and AOT compiled into native ARM which enables better performance and doesn't have any of the JS VM issues Airbnb kept running into. I also prefer Flutter's x-plat approach of drawing all their widgets with Skia as it also mitigates the UI widget inconsistencies they would've had if they tried to wrap native widgets. Flutter widgets follow Material design by default but can also be themed to look like native iOS widgets (https://flutter.io/widgets/cupertino/).
React Native nails the development experience but is plagued with issues which isn't clear if it's because it's architecturally flawed or that it's just poorly resourced and Facebook only cares about resolving their own issues.
I've been burnt by the lack of support in React Native indiscriminately closing issues, which stopped me from wasting my time reporting any more issues and eventually stopped using React Native altogether.
I've been pleasantly surprised by Flutter, it does what it says on the tin, enables a productive dev environment for creating Native Apps from a single code-base and in contrast to my RN experience their support has been stellar, several team members responded to my queries immediately with solutions and workarounds.
The biggest issue I've run into coming from JS/RN is not being able to use reflection due to iOS's AOT restrictions for which you'll need to use code-gen to workaround. Also I prefer JSX for designing UIs, whilst Dart's object declarations enable a kind of code DSL it's not as composable as using a declarative XML markup where you can freely move widgets around to design UIs. Ultimately I hope they provide a similar language feature for using an XML-like markup as an alternative for (and just transpiles to) object declarations.
[1] https://medium.com/airbnb-engineering/react-native-at-airbnb-the-technology-dafd0b43838#4b2bBut looking into Flutter, I think it's undeniable how smart this project truly was. Even if it isn't backed by a popular programming language, since Dart obviously does not fall on that category.
If they “only” pull another AngularJS -> Angular transition. and it’s already a bad thing. If they abandon it, ouch!
C# & XAML UWP layer with Xamarin for mobile. The company behind it has been using for a few years to produce apps and recently open sourced it. I'm intrigued and weighing it against Flutter for my next bit of mobile experimentations.
React Native currently has the very same problem. This is the reason why some very useful native components that require synchronous delegate callbacks (such as UITableView and UICollectionView from iOS) are not available from RN. However, the core team at Facebook is working on a "large re-architecture" that will allow synchronous calls into JS, fixing these issues:
https://facebook.github.io/react-native/blog/2018/06/14/stat...
If you use VSCode, it really is a first class citizen, which makes me happy as I am most familiar with that editor.
Overall I haven't been this happy with development in a while.
[1] Though what happened with Chrome is a shame: https://news.dartlang.org/2015/03/dart-for-entire-web.html
[2] https://www.dartlang.org/guides/language/sound-dart#what-is-...
[3] https://dev.to/rosstate/java-is-unsound-the-industry-perspec...
I'm also working on a similar project.
I'd be really curious to hear some experiences and why you prefer one over the other.
With Airbnb’s announcement around React Native, I feel like native dev is still the way to go.
https://www.kickstarter.com/projects/flutterwireless/flutter...
[also notice that it is in no way affiliated with Flutter and done by somebody in the community]
[1] I can't find any way to contact the author, but here is his blog post about the Studio https://medium.com/@pmutisya/flutter-studio-version-2-41cce1...
Doesn't work on Edge or FF stable.
> (no non-nullable types)
I really wanted [1] to get those into Dart 1 (way back before Swift and TypeScript even existed), but I couldn't convince language team at the time that it was worthwhile.
When we moved to a stricter, sound type system with strong mode, we hoped to get non-nullable types into that and ship them with Dart 2. But, as you can imagine, migrating millions of lines of code from an optionally typed, unsound type system to a sound, reified static type system is a hell of a lot of work. (I'm not aware of any cases where it's been done at this scale.)
We weren't able to fit non-nullable types into that schedule and into our users' migration pain tolerance. There is only so much you can drag them through, and just getting to strong mode was a lot.
There is still a desire to bring non-nullable types to Dart. It probably won't be soon because we want to give our users a break from migration, and give our implementation teams time to take advantage of the new type system. But I haven't given up on them, and our team's new focus on static ahead-of-time compilation makes them more important than ever.
I agree that Kotlin is a really nice language. I hope we can catch up to them with Dart and exceed them in areas.
[1]: http://journal.stuffwithstuff.com/2011/10/29/a-proposal-for-...
1. They added optional nullability syntax to objective-c, a language that assumes everything is null and doesn't crash when you send a message to nil. If your file uses nullability, it's required for the file, otherwise you don't have to use it. Code without nullability annotations using non-null annotated code could interface with the non-nullable code. Errors didn't come up unless you did very obvious things like directly put nil in a non-null argument.
2. They migrated their entire apple library base to have proper nullability annotations. Code that didn't have nullability annotations continued to work fine. Or I think you could just turn off the build error with a compiler flag.
3. Apple introduced swift. Any objective-c code that didn't have nullability defined was assumed to be an implicitly unwrapped non-null. So if you give a null to something not expecting a nil in swift, it would crash.
Apple has a blog article specifying it further here: https://developer.apple.com/swift/blog/?id=25
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I liked this approach for the most part. Migration wasn't that much of a pain, and it was incentivized because I didn't want implictly unwrapped stuff in my swift code.
If you migrated the flutter framework and the dart stdlib to have nullability, then new projects can start with proper nullability annotations from the start, while old projects can progressively migrate files as needed.
Java also has a nullable syntax annotation, and kotlin probably has some sort of java-kotlin nullability interop somewhere. I would really suggest doing it, nullability has given big stability benefits to large projects as it is, and would help adoption in the future as people using something like kotlin & swift for new projects vs flutter itself.
Facebook has done it twice at this scale: PHP -> Hack, plain JS -> Flow JS.
There is the added benefit of being able to reuse assets from your mobile app in AngularDart, which I suspect may see an increase in use along with flutter.
I’m not coming from Kotlin or rust though, but a .net core backend with JavaScript on the front end and Xamarin for apps. I can definitely see us move from AngularJS and Xamarin to flutter and AngularDart though as this move would be a nice improvement.
I’m not too worried about the lack of available projects and libraries on dart compared to say JS, as we typically wouldn’t include some one man hobby project anyway.
That being said, I think we’ll wait and see what happens throughout 2018.
What makes you think this given the library and tooling situation? Is this strictly a "worse is better" thing where lacking modern language features is a plus (at which point I'd argue for Java) or is there a Dart feature that makes you think it's actually an improvement over TypeScript, Kotlin, .NET Core (both C# and F#) or Rust (just to avoid adding more languages to what you mentioned) for enterprise development?
I'm frankly astonished at seeing how something that I see as an extremely clear step backwards as far as languages go is getting so much traction; not sure if it's just because Flutter is that good a tool (in which case I'd think we should be aiming to make the native core available to other languages) that people are willing to root for the whole package or if there's something else.
[1]. Although it'll be a pity. JS is stuck as a compilation target because it's a standard, and it's old, and even then wasm may one day take over JS. Flutter could have been a library, and one could have written in Go or Rust or Java with Flutter bindings. As it is now, I don't know if its possible.
The Android API sets the bar really, really low for improvements.
I'm not sure this is _the_ cause for anything, but it's definitely something that happens. I've seen obvious bugs lingering forgotten on RN just because it's not something they're interested in resolving.
And before someone mentions "open source" some of those are deep structural problems that not anyone can just come and fix since they'd have side effects all over the code base. I've also seen actual fixes lingering for months until someone would decide to review or approve it.
One could argue that Google suffers from this weakness as well.
React Native feels like an in-house development project they've open sourced but don't have the resources to resolve external issues so they've instituted a policy of routinely indiscriminately closing and signalling their intentions to never fix them and by extension removing any visibility of which issues still exist and from anyone else being able to resolve them either. They've done this for 1000's of issues - not going to invest in a platform plagued with issues that stands no chance of being resolved.
Server: shelf
I saw that with JSX somewhere <Row> <Column> <Grid> etc. Made the whole thing look much cleaner.
Email me and I'll see what I can figure out.
Definitely preaching to the choir on that one. I pressed my case as hard as I could before 1.0.
We do still have more freedom to make breaking changes than many post 1.0 languages do because, frankly, we don't have that many users. But every day, the cost to make that change goes up.
> people assume that the language is finalized and won't be too happy being forced to refactor their code when Dart 3 comes out
I was worried about that with the transition to the new type system in Dart 2, but users — internal and external — were surprisingly accepting of the breakage. We don't want to be cavalier about breaking them, of course, but my impression is that there is more room for significant changes than I'd initially assumed.
> But as it is, I doubt that the nice parts of Kotlin will ever make it to Dart.
Dart will never be Kotlin, but I hope we can get to a point where most users don't consider it to be deficient compared to Kotlin and where we have some features to make Kotlin users jealous.
For example:
1. JS is single-threaded, with extremely heavy threads only recently made available. So Dart is single threaded, with extremely heavy threads available.
2. JS is weak-typed, so Dart was made optional typed. Remember, it was made before typescript, so they probably didn't expect that such type-heavy features as ADT would interest people.
Kotlin does the same (for example, internal immutability would be much nicer, but since the JVM doesn't support that, neither does Kotlin).
In Dart 2, the type system is sound and checked at runtime in cases where it can be proven statically safe (downcasts, variance, etc.). That makes it a lot more work to migrate because the code actually needs to run correctly without violating any of the dynamic type tests.
Hack does check type hints at runtime, so it's "sound" in the same sense as Java might be. Is this the same sense in which Dart is sound?
> the type system is sound and checked at runtime in cases where it can be proven statically safe
I didn't understand this. If the code is statically proven safe, why would you need runtime checks?
Both of these languages started out with strict null-checking — Hack because there were too many bizarre falsy values in PHP to allow otherwise, and Flow because it worked out so well in Hack. So neither had to tack on strict null-checking afterwards.
There have been some similar large-scale migration efforts. For example, Hack's record types were built on top of PHP arrays, which don't distinguish between absent and null values. Consequently, Hack's record types didn't distinguish between optional and nullable fields. Furthermore, records support width subtyping by default. This is unsound: you can construct distinct types A and B with A <: B <: A.
After a lot of effort, we did migrate the entire codebase to resolve this unsoundness. Essentially, we changed every record declaration to be an "open" record type and made all new records "closed" by default (referring to whether they supported width subtyping).
The analogue, then, would be something like refactoring every type declaration in every consumer's Dart code to be annotated as nullable, adding explicit null-checks, and allowing them to write non-nullable types as the default thenceforth.
An overflow of Github issues can lead to some issues going unnoticed (depending on whether issues are regularly triaged by a team).
For example, I have a Flutter Android app that has an infinite notification loop bug [1]. I've struggled for many hours (spread over a few weekends) trying to figure out what was wrong. I eventually opened an issue on GH after giving up.
After a few days, I decided to post a question on SO, and someone from the Flutter team saw it. The issue might have gone unnoticed for a bit if I hadn't done so (especially given its obscurity). I believe so because popular projects on GH get a lot of issues, and yours might get buried if someone doesn't pick it up immediately.
The other thing is that when we open issues, and project maintainers try to work with us, we often delay in responding to them. That over time, leads to issue clutter, and probably developer fatigue.
So perhaps we can be better citizens by being more proactive, given that someone who's often paid a lot is taking time to help us with issues.
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I agree with your point on RN and in-house development.
[0] https://play.google.com/store/apps/details?id=za.co.movingga... [1] https://github.com/flutter/flutter/issues/18524
RN enables a fast development model but you'll continually skate into an open mine field of issues where you'll end up wasting time on putting out fires and diagnosing issues only to discover they're known issues they have no intentions of fixing so you'll be spending time on implementing workarounds mitigating broken UX experiences in your App instead of focusing on delivering end-user value. Given the 1000's of issues that have received similar treatment I suspect React Native is just an architecturally flawed experiment and why we'll continue to see more users abandoning it. Hopefully they wont have wasted as much effort and resources as Airbnb's multi-year investment who despite having a large enough dev team to maintain their own fork was still unable to make RN work for them.
With React Native I found the little touch 'click' sound wasn't working on Android. Someone had raised a bug and provided a patch years ago but Facebook still hadn't included it.
I think it’s an improvement over JavaScript, Typescript and the Xamarin experience + tooling, with the added advantage of letting you share language in your clients.
I don’t think dart is great though, it’s just better than the terrible alternatives.
Its type system is also one of the most advanced in mainstream languages, being inferior only to Scala and Haskell.
In comparison, Dart doesn't have ADTs or non-nullable types. For a new language, I consider this very underwhelming.
I'm considering using Flutter for a new project because it seems to be a great platform, but having to use Dart instead of TypeScript is a step backwards.
JS I understand, but what makes you prefer Dart over TypeScript in this case?
- Dart had a lot of features before either JS or TS. Important features like cancellable promises or optional chaining are still missing (I know they might be coming soon). Also some nice quality of life features like named constructors.
- As a superset of JS, Typescript has a lot of idiosyncrasies that might bother people. Personally I don't mind, but people new to web development often find Dart to be a friendlier experience, with fewer pitfalls.
- To me, and this is very subjective, the TS syntax is uglier than either JS or Dart. The types get in the way and add noise to the code. I find Dart's and pretty much any other language's type declarations much cleaner.
However, I have two very big problems with Dart that prevent me from using it as much as I'd like to.
- JS interop is much much cleaner in Typescript/Flow. Every compiled-to-JS language that isn't a superset suffers from this. It's what prevents me from using ReasonML seriously too.
- No support for JSX. I can't go back to writing nested createElement after using JSX
But the main thing for me between TS and reason is exhaustive pattern matching is better in reason, it feels jacky in TS
could I use reasonml/js with flutter widgets and ignore dart?