SwiftUI After 7 Years
Posted by mpweiher 18 hours ago
Comments
Comment by rayiner 17 hours ago
Apple's inability to deploy a new UI framework that's better than the previous one is troubling. This is the company that shifted from Toolbox to Carbon to Cocoa and each step was better than the last. Could Apple build MacOS X and Cocoa today if they didn't already exist? Microsoft's two decades of failure to ship a true successor to Win32 suggests that Microsoft (at least, the operating system side of the company) died a long time ago. I wonder if we'll say the same thing about Apple 10 years hence.
Comment by ksec 8 hours ago
This isn't 7 years of development, but 7 - 12 years after release. And to most these past 7 - 12 years are an ongoing beta development. It is unfinished, unpolished with no end in sight. And I have been extremely critical since the beginning.
But the problem runs much much deeper. It isn't the technology that is the problem, not the devs who are making it. It is the person making the decision as to WHY this was allowed from the get go. WHY this was allowed to be released, or even before all that WHY resources for development of these ideas were allowed in the first place.
For every yes that are a thousand no. Instead a lot of Apple's software development can be summarised as resume or KPI bonus driven development. It is not as bad as Google and Microsoft, but it is clear Apple have this problem a well.
If you look back into Jobs era of Apple software, ( and not just software ) Apple manage to have done most things 2x better with half the resources. The whole Apple now is bloated. And yet everyone is chanting Craig Federighi all the way.
And it is funny because for the vast majority of these 7-12 years I was the only few on HN and Twitter that was extremely skeptical of it, to the point I gave up writing ( or ranting ) about it before majority Swift and Swift UI developers negative sentiment emerged.
And I have often asked the same question every single time, what if they just spend one fifth of the resources to iterate and improve C / Objective-C and Cocoa. All the resources on Swift and everything adjacent to it could have been better spent somewhere else.
I have high hope for John Ternus, hopefully he gets his political game right and manage to change course for Apple software somewhere down the line.
Comment by DarkNova6 1 hour ago
What were the emerging problems that you talk about? I am actually curious because I was quite fond of the DevEx
Comment by ardit33 6 hours ago
it would have been a great language, meanwhile they decided to throw everything out and created a language that it is overcomplex, and it is failing to gain any traction outside iOS / Apple's ecosystem. Basically, if you weren't required to use it, nobody would, which makes it a failure.
SwiftUI, should have been a rendering template/library integrated with UIKit. Also, cleaning up some of the UIKit syntanx and framework (simplifying it), and use SwiftUI as a template for UI, would have been ideal.
SwiftUI instead was pitched as replacement, yet it is not near as capable as UIKit, and it is not feature parity even 7 years later.
Just bad leadership by Apple in this case. (probably many of these decissions were 'promo / resume padding driven' as it happens in many large companies).
Comment by ksec 6 hours ago
> "We need to be true to ourselves, and remember what is important, that is what going to keep Apple Apple, is if we keep us, us."
> "You have got to start with the customers experience and work backwards to the technology.
Right now it feels a lot like Apple without Steve Jobs the first time round. On paper there are a lot of cool tech being worked on. But in the end it was tech from NeXT that really shines.
And a lot of these tech don't actually benefits the customers. If the choice was a language and framework that is slightly harder to developers but brings overall higher quality Apps because the barrier is higher. Compared to a language that wants to replace Assembly to Javascript while being easy to learn like Visual Basic and for everyone to code. I would much rather pick the former.
Edit: I suddenly remember I also submitted a Core Animation introduction video from Steve a while ago on HN [1]. 20 years later we have gone backwards on a lot of things.
Comment by jstsch 1 hour ago
Comment by mpweiher 3 hours ago
That's what Objective-Smalltalk is, or rather, what it started out as.
https://blog.metaobject.com/2019/12/the-4-stages-of-objectiv...
It has now gone further to actually implement Brad Cox's idea of a "Software IC", by taking on ideas from software architecture and metaobject protocols.
https://2024.splashcon.org/details/splash-2024-Onward-papers...
> SwiftUI, should have been a rendering template/library integrated with UIKit.
Do you mean it should have used some sort of XML-ish/HTML-ish templating mechanism? For Interscript, I keep looking at that approach, but so far haven't gone down that road (except for HTMXNative, but there it actually is HTML, so...).
Comment by saagarjha 1 hour ago
Which means Objective-C was a failure, right?
Comment by mac-mc 5 hours ago
Comment by steve1977 17 hours ago
But I feel like Apple wanted to appeal to young web devs and tried to offer something more similar to what these are used to.
Comment by lilbigdoot 6 hours ago
Comment by steve1977 5 hours ago
But I also really liked Objective-C.
Comment by iainmerrick 4 hours ago
Classic iPhone apps have fixed layouts, and classic Mac apps have a big dynamic document in the centre with mostly fixed toolbars around the sides, and dialogs with fixed layouts. Making a really dynamic layout with OS widgets is a huge pain, so most apps sidestepped it.
As Apple gradually added more and more slightly different sizes of iPhone and iPad, making good UI layouts got harder. Even handling screen rotations is a huge hassle! If iOS had proper support for resizing from the start, screen rotation would be trivial, just another window resize.
Xcode had Interface Builder and autolayout, but I found those to be disastrously fiddly and unusable. Maybe some people like them?
HTML has many problems of its own, but it does have good support for responsive layouts. CSS isn't perfect, but it's vastly better than anything you can find in macOS, iOS, Android or Windows.
It seems to me that SwiftUI was trying to tackle two problems at once: React-style declarative UI, and responsive layout. Those are both good ideas, but trying to tackle both in a single uber-framework and deprecating the lower layers was too ambitious. As somebody said elsewhere in this thread, SwiftUI could have been decent as just an optional helper on top of the existing UIKit / AppKit.
Comment by jstsch 1 hour ago
Multiple 'artboards' for screen sizes/ratios are the solution, which basically just means swapping out a .nib in Interface Builder. Better to just make it explicit.
Comment by monster_truck 16 hours ago
I sure hope they can figure out a way through. Whatever it is, SwiftUI isn't it.
Comment by rudedogg 16 hours ago
I think this opinion is heavily shared by Swift developers now, but the messaging every WWDC is always "Swift and SwiftUI is the best way to build apps for Apple Platforms", etc.. If you have to keep telling everyone what they don't believe is true, it's a sign there's a problem.
It feels like someone with a lot of organizational power is disconnected from the pulse of the community. SwiftUI is undeniably clean in a lot of ways, it presents beautifully and fits on slides well, but that matters less and less, and this all wasn't really working out even before LLMs disrupted things.
Comment by steve1977 15 hours ago
Comment by mpweiher 4 hours ago
But they do quietly drop or fix them, covertly acknowledging they were mistakes. Often with this messaging: "we have this new shiny thing that is even better than the old shiny thing (that was really a turd)".
Remember "garbage collection"? Or "modern syntax"? Or CocoaJava?
And with hardware they had their "come to Jesus" moment a while ago. And then hit it out of the ballpark with Apple Silicon.
The one for software is still upcoming.
Comment by joenada 1 hour ago
Comment by refulgentis 16 hours ago
It’s easy to say they were just trying to be trendy and thus the real flaw was the trend is bad and the fault of worse devs than us (the young web devs mentioned)
The thing that obviates that is the trendy stuff works, yet, SwiftUI doesn’t.
(source: I wrote ObjC/Cocoa as early as 2006, and switched to Flutter as my primary dev kit some years ago: it simply doesn’t have the performance issues mentioned.)
Comment by pjmlp 6 hours ago
Comment by sirwhinesalot 5 hours ago
Swift should have just been a much improved syntax over that same runtime. It would have avoided so many headaches. For one they wouldn't have made the awful decision to have return-type overloading and completely ruin the typechecker's performance in the process.
SwiftUI should have unapologetically been a convenient, reactive wrapper over UIKit and AppKit, rather than treating them as deprecated implementation details that devs nonetheless keep having to drop down into.
These decisions come down to ego, of wanting to do away with the old and carve out your own legacy separate from it. Nice if you want a promotion but not so nice if you're trying to make a long lasting ecosystem for developers to build upon.
At least Swift and SwiftUI have a reasonable interoperability story with the past. Can't say the same about Microsoft's graveyard of UI frameworks.
Comment by mbishop 10 minutes ago
Comment by mpweiher 4 hours ago
That's exactly how Objective-Smalltalk started, and it's still very good at being just that.
https://blog.metaobject.com/2019/12/the-4-stages-of-objectiv...
However, it has grown to be, er, a bit more.
https://2024.splashcon.org/details/splash-2024-Onward-papers...
> SwiftUI should have unapologetically been a convenient, reactive wrapper over UIKit and AppKit,
I am also working on a UI "framework" I call InterScript that is (for starters) a wrapper over UIKit and AppKit, and basically solves what I perceive to be the biggest problems of Cocoa:
1. UI specification using object literals. This makes UI-creation very compact and readable. The following example (mostly) reproduces a SwiftUI "Form" example from Apple documentation:
#Grid{ frame: (20@20 extent: 400@340), #rows: [
[ #Label{ text: 'Name' }, #TextField{ stringValue: 'Taylor', frame: (200@24) } ],
[ #Label{ text: 'Email' }, #TextField{ stringValue: 'taylor@example.com', frame: (200@24) } ],
[ #Label{ text: 'Notifications' }, #NSSwitch{ state: 1 } ],
[ #Label{ text: 'Sounds' }, #NSSwitch{ state: 1 } ],
[ #Label{ text: 'Summary' }, #PopUp{ items: [ 'Daily', 'Weekly', 'Monthly' ] } ],
[ #Label{ text: 'Color scheme' }, #NSSegmentedControl{ segments: [ 'System', 'Light', 'Dark' ] } ],
[ #Label{ text: 'Text size' }, #Label{ text: 'Default' } ],
[ #Button{ title: 'Reset All Settings' } ],
] }.
There are actually even better ways of accomplishing this, but this should give you an idea.2. Better communication between model and UI by using the support in the language for polymorphic identifiers and dataflow. Because dataflow is in the language, it can be expressed succinctly without making it hidden magic like in SwiftUI. With dataflow and polymorphic identifiers, you also get a dataflow-constraint mechanism similar to Cocoa Bindings, but again with proper support and less magic.
Essentially the solution to this:
https://blog.metaobject.com/2014/03/the-siren-call-of-kvo-an...
There is more, for example cross-platform, MDA/Naked Objects/Direct2Web style simplification and web integration with HTMX and HTMXNative.
Comment by fidotron 5 hours ago
You can't have Cocoa without Obj-C, or at least a langauge and runtime with that philosophy.
Apple software has been on a clear decline for a seriously long time, and it's propped up almost entirely by them pulling off Apple Silicon combined with how Microsoft have somehow been even worse.
Comment by layer8 4 hours ago
Comment by jrmg 2 hours ago
All of these are unfashionable nowadays, but they’re fundamental to Obj-C (some to the structure of the language itself, some just as idioms) and to the design of AppKit and UIKit.
Now, the fashion is:
Strong typing. Static binding at compile time with no runtime modifications to the type hierarchy. If OO is used, there should be minimal inheritance. Nullability is strictly defined in the type system, and acting on null objects causes, at its most forgiving, an exception, and at its least forgiving, program termination. Notification-based systems may be the outlier here (still in heavy use), but even they are often frowned upon for being too 'loose' and unanalyzable, at odds with the ideals of static typing and static binding.
Comment by mpweiher 2 hours ago
One very important one is that, empirically, it showed how much of what we think we know about language design is ... shall we say ... "incomplete".
After all, Objective-C is a car-crash of a language: take some Smalltalk and jam it into C. Done. How can you write software with this? And yet NeXTStep and Cocoa/CocoaTouch, arguably the most elegant pieces of OS-level/UI-framework software ever, were written in Objective-C. And not despite of it, but because of it.
From a safety standpoint, it's hard to see how you can get worse: all the static type safety of Smalltalk (none) combined with the memory safety of C (none). And these interact.
And while it certainly is possible to use it very, very badly, in practice I haven't seen the horrors that we are supposed to get.
https://blog.metaobject.com/2014/05/the-spidy-subset-or-avoi...
As an example, we got the same level of improvement from doing an Objective-C → Objective-C rewrite with Wunderlist (from WL2 to WL3) that others claim for Objective-C to Swift transitions.
Also, dynamic messaging is said to be slow, yet Objective-C programs consistently outperform the much more static Swift ones.
https://www.amazon.com/gp/product/0321842847/ref=as_li_tl?ie...
And of course, we all know that to do dynamic OO, you need a large runtime and better yet a VM. But it turns out that you can get much if not all of it with a tiny sliver of an extension to portable PDP-11 assembly language.
https://blog.metaobject.com/2024/08/objective-c-is-just-like...
With so much being provided by so little, you can actually put the rest of the language design space to better use, IMHO:
Comment by jstsch 1 hour ago
Message passing, these loosely coupled 'delegates', a mixture of hardcore C, needing to do memory management but also just passing objects around in the runtime... messy, weird... but in the end the right solution to make flexible but performant software. I learned a lot from it. I should dive into the history of NeXT one day.
Comment by dosisking 10 hours ago
Apple got rid of all the NeXT people long ago, with Tim Cook stabbing Scott Forstall in the back, so the answer is No.
Comment by ak39 8 hours ago
In the “enterprise scene”, this sort of purge strategy is likely linked to a big percentage of money wasted and sometimes total failure.
Why do managers keep making this mistake? “Legacy” is only a bad word in IT. :-(
Comment by mutkach 5 hours ago
It is not like their knowledge and experience gets literally purged.
Comment by pjmlp 6 hours ago
Comment by ransom1538 27 minutes ago
Because it was good.
Comment by mpweiher 16 hours ago
Comment by skydhash 17 hours ago
React works well, because it's only an abstraction over the real DOM. React only handles your app state. But the DOM mechanism is still very performant and very much imperative. But I don't think something like React would work well in a mobile app, because the UI tree is often very simple on iOS and macOS.
Comment by kikimora 8 hours ago
Comment by mpweiher 16 hours ago
UI is also very much not functional, and in fact the lack of progress in UI the last 30-40 years can largely be traced to trying to create UI with procedural/functional programming languages, an instance of linguistic-architectural mismatch.
Further reading:
Programs = Data + Algorithms + Architecture: Consequences for Interactive Software Engineering -- Stéphane Chatty.
https://link.springer.com/chapter/10.1007/978-3-540-92698-6_...
Can Programmers Escape the Gentle Tyranny of call/return?
https://2020.programming-conference.org/details/salon-2020-p...
UIs Are Not Pure Functions of the Model - React.js and Cocoa Side by Side
https://blog.metaobject.com/2018/12/uis-are-not-pure-functio...
Beyond Procedure Calls as Component Glue: Connectors Deserve Metaclass Status
https://2024.splashcon.org/details/splash-2024-Onward-papers...
Comment by cloogshicer 16 hours ago
What is your thesis then? What is UI?
Comment by mpweiher 4 hours ago
https://web.archive.org/web/20090424042645/http://heim.ifi.u...
View and model are related, but neither is procedurally dominated by the other. The view is not a subroutine of the model, or vice versa.
They are related entities that communicate in order for the view to function as a representation of its model to the user, and for the model to be manipulated by the user.
To get the details I really recommend the Chatty paper. It is a bit hard to read, but delivers the goods.
Comment by jay_kyburz 1 hour ago
Comment by mpweiher 56 minutes ago
The quote is from the original definition by Trygve Reenskaug, the inventor of MVC (see link above).
https://en.wikipedia.org/wiki/Trygve_Reenskaug
Here some more on that misconception:
https://blog.metaobject.com/2015/04/model-widget-controller-...
Comment by Exoristos 9 hours ago
Comment by bsder 6 hours ago
I disagree, and I believe that the complete stagnation of GUIs is due to ignoring this.
There is no good reason why a GUI system isn't:
Description->Pack->Apply events->Generate assets->Render assets.
At each point you reify the result into an artifact that is everything the next stage needs. This has a couple of nice properties. One property is that everything is deterministic and testable. Another property is that after the pack and apply, everything is now embarrassingly parallel. Another good property is that you have an artifact that the accessibility people can latch onto before you bury it under pixels.
That would be a very functional way to deal with GUIs.
However, we continue inheriting properties and single main threading everything like we're still on 33MHz machines with 8MB of RAM.
Comment by mpweiher 4 hours ago
> I disagree, and I believe that the complete stagnation of GUIs is due to ignoring this.
I disagree with your assessment.
>Description->Pack->Apply events->Generate assets->Render assets.
1. What does that even mean? I don't see a UI in there at all, at best some graphics (Render).
2. That's not "functional". If anything, it looks like a pipeline, so dataflow. But then again, see (1)
3. Not sure why reification, that is turning things into objects, is functional to you. Reification, that is turning things into objects, is object-oriented.
4. MVC was actually created on 5.8 MHz machines with 128KB of RAM (including the display buffer). And still works beautifully today.
Comment by bsder 3 hours ago
And, um, side note: dataflow programming is almost always considered functional programming.
Object oriented, by contrast, is all about hidden state and mutation. I send a message or call a function on that object over there and fingers wiggle and magic happens. But I don't know what or when or even if it actually happened.
And increasing evidence suggests that MVC doesn't work beautifully today because it doesn't parallelize, and it scatters state between uncooperative things. Just ask every single GUI that exists--every single one hangs because somebody made an oops and put too much work on the single, blessed primary thread. Or they have janky scroll. Or resizes leave gunk on the screen. Or your system flashes and jiggles because it's too busy reflowing everything in the universe. Or ...
Comment by mpweiher 3 hours ago
> dataflow programming is almost always considered functional programming
That turns out not to be the case. Dataflow programming shares some aspects with functional programming, they are not the same at all.
> Object oriented, by contrast, is all about hidden state and mutation.
That also turns out not to be the case at all. Heck, there were even object-functional programming languages.
> And increasing evidence suggests that MVC doesn't work beautifully today because it doesn't parallelize,
What does MVC have to do with parallelization, in your humble opinion?
Comment by ardit33 6 hours ago
What you described works only in super simple scenarios. Whink Web 1.0, when Javascript was used for basic form validation at best, and didn't change DOM that much.
Comment by torginus 16 hours ago
Unfortunately when complex state transitions, async, and virtualization enters the discussion, the magic of React breaks, and you have to deal with all that, and also deal with how React's engine handles things under the hood.
Comment by dminik 2 hours ago
Async is just difficult in general though. It's not really a surprise that most libraries/frameworks converged on similar designs.
Comment by torginus 1 hour ago
React also operates on a virtual dom, there's no reason imo why couldn't they just fake that for you.
Comment by dminik 4 minutes ago
But, once you start hitting things like differently sized elements, search and so on, you start running into platform limitations that you won't be able to resolve in React land.
Comment by dgellow 17 hours ago
Comment by poly2it 17 hours ago
Comment by rudedogg 16 hours ago
It's always going to be slower than using something imperative. Trying to process the entire world's state for the sake of purity can feel elegant but it isn't free. And the complexity that gets added to make things performant is worse than just accepting that UIs are going to require you to jump around the tree and modify state.
Every time I go through the trouble of understanding the latest web technique (React, Elm, Signals (the newest solution), etc.) to deal with state management and the DOM, I end up walking away disappointed. There's nothing new in them that you can use to improve what we've been doing for ages in native GUI toolkits.
And to jump back to the original topic, yes, Cocoa was pretty decent, and SwiftUI while nice in many ways tries to Reactify native macOS development and made it worse. And it made Swift incredibly more complex and worse in hindsight.
Comment by kodebach 16 hours ago
Comment by mpweiher 16 hours ago
1. The UI tells the model to change.
2. The model does the change and possible related changes.
3. The model notifies the UI that something has changed.
4. The UI updates itself from the model.
Alas almost nobody does MVC, despite calling what they do MVC.
Comment by kikimora 8 hours ago
How do you collect all notifications on step 2 to fire them on step 3 such that UI does not re-render itself too much? E.g. updating a title of each item in a list of 100 items should not trigger 100 renders. Or 100 layout calculations (which I think is harder to avoid).
How do you deal with situations where on step 4 UI triggers an event that your model happens to listen and the cycle repeats while killing performance?
Because you rely on events how do you avoid “event hell”? That is, a situation when an event handler triggers a change that triggers another event handler that triggers a change and so on. Sometimes it is scrolling or typing, sometimes it is parts of the model subscribed to each other bubbling events to UI.
Comment by mpweiher 5 hours ago
> UI does not re-render itself too much?
Glad you asked! In my Blackbird reference architecture (which is an instance of MVC), I use a coalescing queue to capture the updates. The coalescing is two-level: first, simple duplicates are weeded out. Second, if the update queue gets very full, it becomes coarser-grained, and weeds out duplicates based on that coarser grain. This has multiple steps of grain up to "just re-render the whole UI". Worked like magic in Wunderlist. Except it wasn't magic at all and very simple, inspectable and tractable.
> step 4 UI triggers an event that your model happens to listen
That's not allowed in MVC.
> Because you rely on events how do you avoid “event hell”?
I don't "rely" on events and there is no "event hell". Events are only used in the M→V communication part and there are no subsequent triggers, because the only event is "the model has changed", with an optional payload specifying which part of the model. Important: it must not contain the data that changed, this the view has to fetch from the model once it processes the update event.
Since the only event used is "the model changed", the view cannot ever be a source of those events, so no "event hell".
Comment by layer8 4 hours ago
Comment by kikimora 4 hours ago
This is not about duplicates. For example, sync updates 100 items in a list changing their titles. Items are bound to a list in the UI. Thus, 100 unique title update events triggered.
>Events are only used in the M→V communication
I don’t understand. Button clicked -> model change -> view update -> new event triggered -> model or view updated again … This is not something one would code on purpose, but often an attempt to create relationships between view. Like a custom layout code. Might not include model at all, just views being updated in an event handler trigger more events and more updates to views.
Comment by mpweiher 1 hour ago
Those "updates" go in the queue. When the UI gets around to updating itself, it looks at the queue and invalidates all the UI elements that refer to the model items in the queue.
It then updates those elements, using the coarsening to update larger elements in bulk if that becomes better.
> Button clicked -> model change -> view update -> new event triggered -> model or view updated again
Once again, that is not allowed. View updates are not allowed to trigger any events in MVC. A model → view update updates the view. That's it.
The only event is "model changed", so it also doesn't make sense for the view to generate those events.
Comment by fschuett 57 minutes ago
class DataModel:
def __init__(self, counter):
self.counter = counter
def layout(data, info):
return Dom.create_div()
.with_child(Dom.create_text(str(data.counter)))
.with_css("font-size: 32px;")
def on_click(data, info):
data.counter += 1
return Update.RefreshDom
model = DataModel(5)
window = WindowCreateOptions.create(layout)
app = App.create(model, AppConfig.create())
app.run(window)
So, there's no "automatic" re-render, a callback has to return "Update.RefreshDom" or "Update.DoNothing" (default).Now to your questions:
> How do you collect all notifications on step 2 to fire them on step 3 such that UI does not re-render itself too much?
Diffing, and then caching very aggressively. The click causes the model to re-call the layout() fn to return the entire DOM, however, there are ways to make this step very fast (arena allocation / no allocation). Then this gets diffed with the previous DOM state and the framework internally reuses everything it can (with user providing keys for list items, like React does).
> How do you deal with situations where on step 4 UI triggers an event that your model happens to listen and the cycle repeats while killing performance?
Azul has a "max recursion depth" of 5 and then just throws an error (infinite cycle). So, it will invoke all the relevant callbacks for a frame, then "sum up" all of the Update enums (i.e. one callback returned RefreshDom -> now we need to repaint).
> Sometimes it is scrolling or typing, sometimes it is parts of the model subscribed to each other bubbling events to UI.
Scrolling, selection, typing, etc. are handled by the framework. To make something editable, you need to set "contenteditable=true" on the Dom node (like on the web). Then, on text editing (which can also come from IME, a11y input, copy-paste), you get a "text changeset". The callback can then "reject" the changeset or allow it (default, since you already set contenteditable before).
Azul has a "dual update pattern" for performance here, i.e. the DOM itself is immutable until the next layout() call, however for "quick edits" like dragging a node you obviously don't want to call layout() again and construct an entire new DOM tree. So there, you just (conceptually, don't know the current API for this):
def on_div_dragged(data, info):
mouse = info.get_window_state().mouse_state
info.set_css_property(info.get_hit_node(), "transform: translate(%s, %s)", mouse_state.x, mouse_state.y)
# store in data model or node if necessary
data.user_mouse_pos = mouse_state
return Update.DoNothing # no re-render here
So, if another callback fires in between, the data model is still properly up to date. Azul also aggressively reconciles focus, scroll position, selection, text cursor position, etc. But Azul does not allow "one event auto-triggers another" like SolidJS does, it looks nice on a slide deck and then is a pain to debug Rube-Goldberg state machines.This also works for text input or updating images (i.e. you don't need to call layout again on text input). Update.RefreshDom is for "larger / structural" changes, i.e. something like a route switch in a SPA-style app. Azul tracks the text cursor position by diffing the actual text, so the user code doesn't have to track the text cursor and state is preserved during a diff (it can also retain heavy elements).
For large lists, there is a native "virtualized view" DOM node with a callback that is being called "during" layout (after the size of the container has been determined, then the framework asks you to render your DOM, given the scroll position). So, that can be diffed, too. You never render in the DOM more than ends up on screen, so the perf is manageable.
Scrolling and retaining scroll positions inside a virtualized view is still an ongoing topic (not impossible, you just have to have functions to measure the DOM items before you return them, to estimate how much you need to render, and then do the math for "where are we right now, where is the scrollbar, how big is the virtualized view in relation to what we're rendering" - so the framework can set the right scrollbar size and position).
Again: please don't use or post Azul here on HN yet, docs are still slop and undergoing review, API is unstable until I have some apps going, but I just wanted to answer these questions.
Comment by wk_end 9 hours ago
Is the UI updating itself automatic or manual? Because if it’s manual, that’s precisely the error-prone part that you’re saying this approach somehow solves - you’ve done the “How to Draw an Owl” meme. If it’s automatic, that doesn’t seem especially different from the React/Redux/Elm/SwiftUI approach (as a sibling points out).
Comment by mpweiher 5 hours ago
Different formulations of M-V-C have the C deal with more complex interactions, with sequences of interactive prompts like wizards.
The update is essentially automatic, and yes: MVC already solved the "problem with MVC" React/Redux/Elm/SwiftUI claim to solve. In 1979.
Comment by jay_kyburz 1 hour ago
Comment by asa400 9 hours ago
Comment by mpweiher 5 hours ago
"We solved the problems of MVC by properly applying MVC".
https://blog.metaobject.com/2017/03/concept-shadowing-and-ca...
Comment by LoganDark 9 hours ago
Comment by mpweiher 5 hours ago
Conceptually, the UI re-renders itself completely in order to always be an accurate reflection of the model.
That is the #1 job of the view: be an accurate reflection of the model.
And re-rendering itself completely is a safe way to implement that requirement.
However, the UI can also look at the model in more detail and figure out what parts need to change, as long as the effect is the same as re-rendering everything.
And the model can tell the view that specific subparts of the model have changed to make that job easier for the view.
But if it can't figure out the details, the fallback is to re-render the entire view from the model. But not to recreate the view. The view sticks around.
One way of doing this optimization is "damage rects" like Cocoa does. Another are the polymorphic identifiers used in the update queue of Blackbird.
Comment by jay_kyburz 1 hour ago
Comment by ardit33 6 hours ago
MVC, the controller is the intermediary between the services/data models, and the views. That still one of the best / simplest way to build large apps. MMVC is just a variation of it, with the models being able to communicate state to views and bypass controller if needed.
MVC, is still one of those 'fundemental as simple as it gets, and it gets the job done' patterns.
Comment by mpweiher 5 hours ago
Your interpretation is a common misconception, for example promulgated by Apple. It is not MVC.
https://blog.metaobject.com/2015/04/model-widget-controller-...
https://blog.metaobject.com/2017/03/concept-shadowing-and-ca...
"A view is attached to its model (or model part) and gets the data necessary for the presentation from the model by asking questions. "
https://web.archive.org/web/20090424042645/http://heim.ifi.u...
Comment by mpweiher 17 hours ago
Comment by skydhash 17 hours ago
I didn't say that.
User interfaces representation are mostly trees. And with functional programming you basically have Tree2 = f(Tree1). Until f is done you can't do anything really. React has a lot of escape hatches to improve performance, but they are escape hatches, not an endorsement of the architecture.
With imperative programming (and OOP), you only have that single `Tree`, which you update at will. Less elegant yes, but we have modularization to help us there. What Emacs does is to keep that `Tree` as a single mutable object, but have the code be functional, while the results are imperative.
Comment by zombot 8 hours ago
I don't think we have to wait 10 years, we can say it today.
Comment by simondotau 5 hours ago
In fact I can think of at least three instances (at very different magnitudes) where Apple has dragged itself out of a stupid hole they dug for themselves.
Comment by brnt 17 hours ago
Comment by stasomatic 44 minutes ago
Comment by graypegg 16 hours ago
I’m no huge apple fan, but I didn’t really think the 17 was more than a regular boring spec upgrade, which seems fine all things considered. (Currently on an iPhone fucking 17)
Comment by brnt 5 hours ago
Comment by sandoze 16 hours ago
Data Flow: The author claims there’s no way to know when things update. Not only does experience help here but there are profile tools that tell you when and where things are updated. This isn’t black magic. Keep Views small, be careful how you hand around data. @environment is super cool but can have a cascade effect. This was greatly improved iOS 17+ and I wouldn’t support anything older than iOS 17.
GeometryReader: Occasionally I’ll use this. It’s kind of a necessary evil when dealing with certain view complexity. It can also be a sign that you’re doing something wrong.
API Stability and performance: Apple users upgrade. There’s no reason that you should be supporting iOS 17 at this point — even iOS 18 is roughly 2%% of our user base across several apps. I’ve been using SwiftUI without major performance issues but I also don’t early optimize. I profile and fix as needed. One of the early studios I worked for wrote all our games in UIKit as prototypes, when performance tanked we’d switch to the appropriate tools (eg. OpenGL) where it was necessary — like in the core game.
I could go on but in the end just use the right tool for the job, if you’re not proficient in SwiftUI or it isn’t going to work for your cross platform project, you have a lot of other alternatives. For me though, it’s been amazing to work with. I stepped away from iOS programming for 3 - 4 years because I was burnt out using storyboards, dealing with massive view controllers, and all the boiler plate it’d take to get a view up and going in UIKit. SwiftUI roped me back in.
* Quick addition edit: Cross platform for iOS, iPad, macOS has never been good. I’ve found recent updates have made things better to the point of tolerable and it’s nothing like when we had to post-fix an ~ipad to our Nibs — There has never been a ‘glory days’ of cross platform Apple UI libraries.
Comment by _s 9 hours ago
SwiftUI is great for "surface level" UI, that has some basic data bindings - think a basic CRUD app, which needs some navigation, and the ability to scale across the smallest iPhone to the largest macOS screen, from touch gestures to mouse input.
If you ask anything more of it, then you need to start branching off into specific libraries / tools / frameworks (UIKit, CoreAnimation etc) - which is much easier now too, but you'll always have a bad time if you try to mix the two in a single "view" / "frame".
I'm not surprised that's still true today.
Comment by Exoristos 9 hours ago
Comment by joshuakcockrell 8 hours ago
Comment by VerifiedReports 6 hours ago
Strong disagree on that. @environment is an amateurish hack, basically sugar-coating global variables as a solution to SwiftUI's poor design.
I had a strong background in UIKit; then for a product I'm building for myself, I decided to go all-in on SwiftUI. This was after it had been around for four years or more.
SwiftUI turned development, which I used to enjoy and feel good about, into a tedious trudge. I read everything I could, did the Stanford class, adopted "best practices," and really made an effort to do it right. It blows.
Unless your app is a trivial master/detail data-viewing app (as pretty much every SwiftUI example is), you wind up thrashing and performing all kinds of state-tweaking gymnastics to herd your application along through whatever tasks the user is supposed to be doing. Heaven forbid you need to walk the user through a series of steps to do or create something.
It's going to be a testing nightmare, and it suffers from every bit as much opportunity for data to get out of sync between the model and the UI as "traditional" app structure. Apple touts the "single source of truth" as gospel in SwiftUI, but you can't have that. First of all, Swift's official position is that you should "prefer structs" over classes. But (and this is one of Swift's hokier characteristics) structs are passed by value (copied) instead of by reference. So your "single source of truth" is broken after the first function call; your data are copied all over the place.
But there's another problem with the single-source mantra: You can't just expose your core model to the UI for direct manipulation, so you have an intermediary (the so-called "viewmodel"). But that intermediary must have temporary data structures to shadow those in the core model, so the UI isn't messing directly with the model, and the user can cancel or fail when changing things without messing up the integrity of the model.
So now, once again, you don't have a "single source of truth."
The problem isn't understanding the paradigm; it's making it do useful work. Some people love to mock OO for its early and obviously cumbersome and pointless idioms, which were quickly abandoned by experienced programmers. What remains of OO is still quite useful. I predict the same for... whatever the this mess is called. You waste so much time trying to follow the gospel of "MVVM" for no actual benefit. As I went through it, re-reading and re-digesting various pundits' viewpoints... I realized that I just had to start from scratch and build something that pays off instead of a bunch of useless ceremony.
I switched everything to classes, built managers (controllers) for the big categories of data and tasks I need to organize, and inject whatever objects I need into each view.
As for the rest of SwiftUI, its state is disgraceful. It excels at scaling UI for different screen resolutions; something that Apple neglected for waayyyyy toooo long. But there was no excuse for Apple to release a UI framework that basically didn't support the most fundamental UI paradigm of phone applications: a stack of progressive views that are programmatically manageable.
How many half-assed attempts has Apple trotted out, to do what UIKit does with ease? The latest is NavigationStack, which is still pathetic. The only way to navigate more than a level deep is to create an array of one datatype to serve as NavigationStack's "path." But this is designed to be an array of a single datatype. Look at the examples for this thing: They're applications that present a stack of views that each show... an INTEGER. In decades, I have never written an application that needed to stack up a pile of views that all show the same datatype.
And yes, I know the workaround for this where you create your own struct datatype and then fill it with enums, one for each view. But come on; the fact that Apple even rolled out this ludicrous design tells you that the talented architects have left the building.
Comment by willtemperley 5 hours ago
You can use a tagged union for the "one datatype", thereby allowing your views to accept any datatype you provide in the enum. Or use NavigationPath.
Comment by mintflow 9 hours ago
After two many trial and fail, now it's quite clear to me that for simple UI I will use swiftUI(such as help sheet or simple toggles), for complex and performance first, I will just use UIKit instead, it save a log of time and actually the imperative UIKit is also quite easy to read and review
the feasibility of review is important because code is not mainly written by agent, though as my understanding of UIKit grows I can smell the bad part and let it rewrite
Comment by il-b 5 hours ago
Comment by cosmic_cheese 17 hours ago
These frameworks have a number of good ideas but they don't necessarily combine in a way that transcends high quality traditional imperative frameworks with declarative-reactive bits sprinkled throughout, at least for more complex apps. SwiftUI and its ilk work best for super simple tabs-and-flat-lists sorts of apps.
Comment by rumori 17 hours ago
Comment by norbert515 17 hours ago
And because of the open source nature you can always drop down in layers, just a few weeks ago I made a very specific engine optimization, all while the application code on-top can stay declarative!
Comment by cosmic_cheese 17 hours ago
It also doesn't fix problems inherent to declarative UI, like readability breaking down easily and certain things that would be a cinch in an imperative framework being extremely awkward to implement.
Comment by kodebach 16 hours ago
In my experience the solution is often to use the appropriate architecture underneath your UI layer. Basically you build a data structure that represents your UI and always hand this entire structure to the declarative UI layer. Underneath the UI layer, you can still use imperative code to manipulate the data structures. The benefit of the reactive/declarative approach is that you don't have to think about how changes in the data need to be reflected in the UI. That's the framework's job.
Note: With "data structure" I don't mean "build a shadow DOM". I mean something specialized to your use case.
Comment by cosmic_cheese 15 hours ago
In SwiftUI, that means endless chains of modifiers, and in Compose this means monstrous constructors and modifier chains. Both get really ugly and painful to read quickly, and there's not a lot that can be done about it apart from breaking everything out into smaller views (which only goes so far). The amount of boilerplate saved isn't worth the trade, in my opinion.
In an imperative setup, there's still a lot of code but there are more options for organization, readability, and overall clarity. One can break things up with comments, break out setup into functions with self-explanatory names (that the IDE can then quick jump to, as a bonus), etc.
Yes, it's easier to get tripped up with imperative frameworks if one isn't thoughtful with managing their data, but much of the time that code only needs to be gotten right once.
Comment by well_ackshually 3 hours ago
Which is now being fixed by the Styles API (https://developer.android.com/develop/ui/compose/styles) which are easily reusable.
Comment by clumsysmurf 5 hours ago
> Data flow in SwiftUI is indeed reactive—but sometimes I wish it wasn’t, because it’s reactive in all the wrong ways. It often reacts to changes it should ignore, and it ignores the changes you actually care about. To me, SwiftUI’s reactivity is a black box: It makes achieving predictable behavior almost impossible.
In Compose, seeing rememberXXX(key1, key2) sprinkled all over with keys makes following the code difficult.
Then add some side effects like LifecycleEventEffect(Lifecycle.Event.ON_RESUME) { ... read permissions and render warning if we can't do something ... } and it becomes even more difficult to comprehend. Much of the Android framework APIs are not reactive, and polling on these UI events is still necessary (permission could have changed if the user put the app in the background, and you can't listen to them via Flow etc).
As the author says, these frameworks make the static data dependencies explicit but often at the expense of what is changing and why.
When I see rememberXXX(key1, key2) { } the first thing that comes to mind is, why would key1 and key2 change, and often that is not obvious.
Comment by sujee 3 hours ago
For my app which is a AI chat app, I needed to load and show a large number of chat items in a list, SwiftUI is really bad at this. Another issue is, most of Swift markdown libraries don't perform perform well because each elements are rendered as SwiftUI views which introduced a lot of issues So I built my own renderer using TextKit. Even basic things like Settings window is broken. But I still prefer using SwiftUI as It gets the work done faster and I can always fallback to AppKit.
I find that web tech like React are worst than SwiftUI. React also has re-rendering and state management issues
Comment by searls 1 hour ago
I get people are upset, but the edge cases and frustration in no way feel like fundamental failures—just stuff they haven't gotten around to yet. Yes, they should have gotten to them all sooner but that doesn't convince me they won't eventually.
Comment by spacedcowboy 16 hours ago
Just MHO, and it’s not going to stop the juggernaut, but there’s just no appeal in moving there for me :( If (when ?) Apple drop ObjC, that’s the day I move to Linux
Comment by blltprfmnk 16 hours ago
Unfortunately although Swift seemed promising at first, by the time Swift 3 rolled around a lot of people were actively frustrated and moved on from iOS development. Having actual experienced hands guiding that ship could have led to something great instead of the mess that is there today.
Comment by spacedcowboy 5 hours ago
Memory management, Generics, Fast enumeration, Properties were seamlessly added to ObjC over the years without adding to the cognitive load of the language, which is minimally more than that of C. It’s a small superset of C and (for me) hits that complexity/expressiveness sweet spot. YMMV, of course.
Comment by kccqzy 14 hours ago
Comment by blltprfmnk 14 hours ago
Agree that SwiftUI was just jumping on a bandwagon and would say that the design of SwiftUI clearly strains the poor language design choices in Swift.
Comment by frizlab 15 hours ago
Swift is incredibly better than ObjC on so many ways it’s just not comparable. I used it since day one and never looked back. (And I was deep into the ObjC ecosystem, having written very low-level frameworks, and having loved it.) Yeah, first versions of Swift were raw, but now it’s just THE language; I used for everything (obviously Apple soft frontend, but also the web, the backend, etc. Even android dev I would do with Swift though I do not have the occasion for now.)
Apple will never drop ObjC support IMHO. But most new frameworks will be Swift-only.
SwiftUI is a step backwards from AppKit in the sense that we lose control over what’s possible when using it exclusively. But 1/ it’s much simpler for doing simple things and 2/ we can drop down to AppKit when needed. All in all, it’s good that we have it.
Comment by joshuakcockrell 8 hours ago
Comment by ardit33 6 hours ago
Comment by jshier 16 hours ago
Comment by dzonga 1 hour ago
1. the language had all the right hook points to replace python - but then it was closed off in the apple ecosystem for a while. then it was made to be complex as C++ as time went on. if Swift had remained as simple as Go - and Apple had made a push for swift to go beyond apps in their ecosystem the language for data/ml would be swift
2. in regards to swiftUI - almost the same point as 1. react native took over cz it was a simpler more open ecosystem. then eventually most people stopped bothering with native apps (they're used to track you) - web apps are equally good. hence for most people they use native apps for maps, banking.
Comment by emehex 16 hours ago
Comment by CharlesW 15 hours ago
I think this is true. SwiftUI became "very good" as of iOS 26 (in part because the performance gap mostly evaporated) and continues to get better in iOS 27. Over and over, I see UIKit developers trying to do things "the UIKit way" in SwiftUI, and they'd rather write TFAs instead of considering that they may need to skill up and learn to write effective and idiomatic SwiftUI.
Comment by mirsadm 6 hours ago
Well I've been doing this for a pretty long time and I'd like to think I'm pretty good at it.
Comment by O-stevns 6 hours ago
Comment by oefrha 9 hours ago
Comment by jshier 16 hours ago
Personally, SwiftUI makes the 80% so much easier that, even if the remaining 20% requires dropping down to UIKit, it's worth it.
Comment by frizlab 15 hours ago
Comment by happytoexplain 10 hours ago
Comment by happytoexplain 11 hours ago
SwiftUI/React/etc don't introduce that pattern, they simply enforce it (and add efficiencies).
If a developer isn't familiar with the pattern, it's not because they are a UIKit dev, it's because they are inexperienced.
Comment by ajpaulson 8 hours ago
Comment by archagon 15 hours ago
Comment by cosmic_cheese 9 hours ago
This is incredibly frustrating, particularly now that more UIKit and SwiftUI widgets share underlying implementations.
Comment by lonelyasacloud 3 hours ago
On macOS it is still comes up short on a lot of the GUI functionality. Stuff like window management, decoration, focus, undo/redo, finder tree type views etc. What Apple have implemented seems okay to me for iPad, iOS etc, but is not up to the standards users' expect for non-trivial native desktop applications.
With enough determination most of the omissions on macOS can be worked around by breaking the SwiftUI encapsulation and delving into AppKit or jarringly inelegant solutions. All of which are somewhat liable to ended up binned when/if Apple pull their fingers out. I had higher expectations of Apple, and overall, it's easy to understand why it does not have a stellar reputation.
As to why it's a bit rubbish on macOS; SwiftUI is largely a mapping to UIKit, AppKit etc primitives. At a guess Apple wants to reduce that number and are seeking to minimise investment in moribund technology.
Comment by mathverse 1 hour ago
There are still a lot of rough edges when it comes to look and feel on Apple platforms but it gives me the performance and speed while also being multiplatform.
Comment by peheje 16 hours ago
The boundaries aren’t perfectly clean, and that’s fine. But the separation gives you a useful way to think: structure this first, style it later, add behaviour where needed.
My experience with Compose—though I suspect SwiftUI people will recognise the feeling—is that I have to think about everything, everywhere, all the time.
Then we add some MVVM/UDF flavour. The "ViewModel" knows nothing about the view, despite usually serving exactly one screen. Add some "MutableStateFlow"s, combine them into "ScreenUiState", expose it as a "StateFlow", collect it with lifecycle awareness.
Beautifully decoupled. Extremely testable.
Then the organisation writes no unit tests and relies entirely on two-hour nightly screen tests.
A welcome-page refactor breaks the profile page.
“Didn’t you check the nightly build?”
No. It runs at night.
“Well, that’s your responsibility.”
But you broke it.
“Yes, but it’s your code.”
Then why did we ship it?
Fine. Schedule the postmortem with my mother.
And I’m not blaming mobile developers here. I’m frontend, backend, full-stack, I think AI engineer now. I have personally helped make simple things complicated across the entire stack.
What I like about the web is that one simple screen can be vanilla JavaScript. Another can use Vue. Another can use some specialised spreadsheet component.
People react to that with horror: what if components are duplicated, behave or look slightly different?
Fair concern. But that is real coupling with visible consequences and trade-offs. Somehow we have started treating coupling as something abstract that only exists inside code, rather than something that should produce an actual benefit when removed.
HTML. CSS. JavaScript. Or something close to it.
Maybe I’m getting old.
Comment by dosisking 8 hours ago
I guess I'm even older, because I prefer HTML4, without CSS. And I like using tables for layout instead of divs.
I always hated CSS.
Comment by willtemperley 5 hours ago
NavigationStack has been around since iOS 16, @Observable since iOS 17. and I'm not sure if the author is aware that GeometryReader hasn't been necessary since iOS 18 added onGeometryChange modifiers. Nearly 100% of users are on iOS 16+.
I'm doing some fairly complex work with SwiftUI and I find most components work identically between iPad and macOS. I can work for a week without needing to test on an iPad.
There are problems with SwiftUI for sure: I'm finding macOS performance on an M2 Max is far worse than an iPad M1, especially with animations. Toolbars are very inconsistent between platforms and the compiler timeouts are a real pain (hopefully Swift 6.4 will fix that).
Comment by viktorcode 3 hours ago
I think the author does not understand how and why to use GeometryReader at all. He literally said "you find yourself wrapping everything in a GeometryReader" which is a different thing from simply measuring. For measuring you could always put GeometryReader into `.background()` and use that to avoid messing with the view layout. Also, "wrapping everything" is a good sign you are doing something wrong.
Edit: by the way compiler timeouts are not a SwiftUI issue: it is a Swift issue. You can create a timeout situation in pure Swift. For SwiftUI specifically this situation is addressed in the upcoming OS27 SDK.
Comment by happytoexplain 16 hours ago
SwiftUI is a laudable attempt to idiot-proof UI, but it sacrifices too much and ultimately fails.
Comment by Klonoar 1 hour ago
Comment by frizlab 15 hours ago
Comment by sunnybeetroot 15 hours ago
/s
Comment by frizlab 15 hours ago
Comment by sunnybeetroot 15 hours ago
Comment by ChrisMarshallNY 1 hour ago
SwiftUI is great for test harnesses and admin utilities, but I won't use it for shipping software. I have one app that I rewrote in SwiftUI, just so that I can say that I have shipped it, but I am still using UIKit for most of my apps.
I'm not thrilled with UIKit, but SwiftUI has kind of withered on the vine.
Comment by harrouet 5 hours ago
But is there a single UI abstraction that succeeded in affordability for newcomers while maintaining performance and solid architecture?
It is high time to solve the write-3-apps for each usecase (iOS, Android, Windows). I use MAUI on some projects but it is still not perfect.
The way forward for Apple is to open source more and more and let the Swift community build a cross-platform solution.
Comment by emehex 17 hours ago
What does this even mean? There are hundreds of thousands of apps in the App Store that are 100% SwiftUI. They are real. And they are very much "production grade".
The only people still complaining about SwiftUI 7 years later are the UIKit holdouts that never took the time to properly learn how to use it.
Comment by brailsafe 15 hours ago
The first is a statement of quantity, the second is a statement of quality, dubiously supprted by the first.
The Mac Settings app still lags between panes years after it was redesigned to look like iOS. I would think that if they had a viable way build a high quality and performant app with even relatively basic UI components (if they cared to do so) they'd do it for the 1 app that's deployed to every mac.
SwiftUI does work in certain circumstances, and does work for allowing people to shit out their ideas faster, but it has struggled with the aspects described in the video. Some companies don't care either, and turnaround time is paramount, but in this discussion it's about quality compared to what came before.
Comment by saagarjha 1 hour ago
Comment by pupppet 15 hours ago
Comment by saagarjha 1 hour ago
Comment by dagmx 15 hours ago
Comment by wahnfrieden 9 hours ago
Comment by zombot 8 hours ago
Comment by ardit33 17 hours ago
It is a newbie trap. It is great at producing simple apps, or things that don't require intense scrolling, or anything with heavy animations and precise layouts, but when you do something smooth, it is not it. It feels more of a React Native competitor, than a true UIKit replacement.
Also, almost everything that Apple has re-wrote with SwiftUI, came out worse as before (Settings, Spotlight, etc), and that doesn't help.
With AI coding... SwiftUI lost its edge/advantage (easy to layout screens), as now you code less of that directly, and might as well just go fo the framework that allows the most flexibility and gives you the best results for your users.
Apple really needs to either double down on it, and make it such that it has everything that UIKit has (match both features and performance), or just turn it into another optional framework, just as Interface Builder (.xib files) back in the day of Objective-C.
Right now it heavily promotes it as a first class citizen, meanwhile the features are not even parity with UIKit. It is so misleading to newcomers to the platform.
Ps. The other upsetting thing about SwiftUI, is that it has hurt the Swift language as well, as the team has had to introduce all kinds of hacks, or obscure features to the language in order to make it work, which made even the Swift language experience worse and more complicated than it should have been.
Comment by Razengan 17 hours ago
On the contrary, I think AI has made it EASIER to approach SwiftUI now, because AI makes up for SwiftUI's biggest weaknesses: the many ways of doing everything, Apple's wonky documentation and the need to know when to fall back to AppKit/UIKit.
Comment by ardit33 16 hours ago
In car terms:
UIKit - Manual Transmission - you control everything, but a bit of a chore
SwiftUI - Slushbox Auto Transmission - easier to drive, sucks for performance
UIKIT+AI Coding - Dual Clutch Transmission - both great performance, and easy to control/drive
Comment by sampton 17 hours ago
Comment by ardit33 5 hours ago
But, SwiftUI is being pushed as the way to do UI, and as a replacement for UIKIt/the future of apple, where it is not even near feature parity with it. That's the most troubling part of it.
I wished apple just made it as a Template Rendering framework, and integrated wit with UIKit, and just modernized UIKit a bit.
Comment by myko 10 hours ago
Comment by emehex 16 hours ago
Comment by wahnfrieden 9 hours ago
Comment by the-golden-one 17 hours ago
Comment by tonyedgecombe 17 hours ago
Apple has at least been consistent on UI frameworks.
Comment by dgellow 16 hours ago
Comment by masfuerte 16 hours ago
Comment by VCFundedGenYer 15 hours ago
WPF is still around and have been spruced up as of late.
UWP was the DOA Windows 8/8.1/10 app format that was super restrictive, strange to develop for, and non-portable. It's basically MS's equivalent of SwiftUI.
Comment by Razengan 17 hours ago
Back when I wanted WPF to succeed, Microsoft was barely using it in any of their own apps.
Apple has used SwiftUI in their OS more than MS/Windows did, and there's quite a few apps on the App Store that -seem- to be made with SwiftUI.
Comment by Razengan 17 hours ago
I went through Visual Basic, .NET, WPF, Cocoa, and other random frameworks all professing to be the promised panacea for UI, but I think SwiftUI+SwiftData is the best environment ever.. IF only it could reach its full potential, i.e. do everything that Apple's "legacy" APIs can do.
I even tried using SwiftUI for games: https://i.imgur.com/5aTWbft.mp4
The biggest/worst hurdle in the "modern" dev experience is Apple's insistence on a yearly update cycle and the way they advertise those updates: You have to wait for the next WWDC and suffer through videos of uncanny-valley presenters, hoping to catch a glimpse of something that fixes the shit that was bothering you since the last WWDC.
3rd-party sites like hackingwithswift.com & swiftwithmajid.com provide invaluable info that Apple's own docs should.
At least the Swift language has been getting more regular updates since it went open source.
There's no way I'd dare to take on a full Apple-platform app project alone on my own, but I've started dabbling in it again thanks to AI: Codex even converted an old app I made in Visual Basic 900 years ago and had it running in SwiftUI within minutes!
I've even tried to get AI to sift through the WWDC video transcripts so I won't have to waste my mortal lifespan on that.
Comment by zer0x4d 16 hours ago
Comment by sunnybeetroot 15 hours ago
Comment by CharlesW 15 hours ago
You may like my project https://charleswiltgen.github.io/Axiom/ (FOSS). I was in the same place a year ago, and initially created Axiom as a private skills suite before deciding that it was too helpful not to share.
Comment by steve1977 17 hours ago
And that's really sad, because earlier Mac OS X (and even OPENSTEP to a degree) was an Eldorado for boutique developers, not least due to frameworks like Cocoa and Objective-C (despite all the hate it seems to get).
If you knew C, it was not hard to grasp Objective-C (at least it was much easier than say C++ and MFC on the Windows side of things).
Comment by Razengan 16 hours ago
My first Apple purchase was an iPad I got for my aunt, and I loved how streamlined yet powerful it was so I installed a VM on Windows to dabble in iOS development, and fell in love with the sheer consistency of macOS, iOS and their APIs.
This was during the era when Microsoft was still figuring out whether to keep the Start Menu and replace the whole Windows UX with a tablet UI, so it was an easy jump.
Almost never looked back, and whenever I do I'm glad I jumped.
Then came Swift and I loved it, but then it took literal years to catch up with everything you could do in Objective-C with the Apple APIs. SwiftUI is having the same problem but for much longer :(
Comment by viktorcode 5 hours ago
I don't get this part. You can literally rewrite Obj-C code verbatim in Swift and it will work. The only missing part is C macros.
Comment by Razengan 3 hours ago
It took a while to get there. They didn't have native Swift APIs for some things like URIs etc until later.
Comment by Razengan 6 hours ago
Comment by interpol_p 8 hours ago
I can render Metal shaders trivially in SwiftUI. Rendering glows, and blurs, and animated effects is much easier in SwiftUI than in UIKit, just use `.blur(radius:)` or `.blendMode(...)`
I have used AppKit and then UIKit since its inception. Creating visual effects like layer masks that modulate the opacity of underlying views is trivially easy in SwiftUI — far easier than the boilerplate and constant bookkeeping that CALayer's mask requires.
So a lot of the advanced full-screen animations in some of my games and apps are SwiftUI, because they are performant, provide the cool effects and animations, and work great. A lot of the simple get-the-job-done views and tool palettes in my apps are also SwiftUI, again because they don't ask much and get the job done, and look great.
However, where SwiftUI falls down is exactly what was demoed in the video: large collections of thumbnails that fetch asynchronously? Use UIKit. Multi-thousands of items in large, complicated lists? You can try SwiftUI, but you'll need to learn how to optimize it.
Other things, not mentioned in the video, that are more annoying in SwiftUI: want to take control of a transition between views, end-to-end? Not really possible in SwiftUI. There are bugs with ZoomNavigationTransition that affect all of Apple's own apps, and you aren't gonna be able to fix them without switching to UIKit.
Comment by saagarjha 1 hour ago
> We started with @State, @Binding, and ObservedObjects. Then Apple realized the performance was disastrous and SwiftUI was re-rendering views all the time. That’s when it introduced the Observation framework and the @Observable macro. They tried to solve the problem with compiler tricks, but it clearly wasn’t enough so the layout engine continued its guessing games.
Not why @Observable was introduced
> In SwiftUI, you can never know for sure how many times a view will update and, when it does, why it chose to.
Instruments tells you these days
> That demo project from the SwiftUI tutorial has a very standard, non-custom one. You build the project with the latest Xcode and launch the app on the latest macOS—only to get this.
Yeah, it's a demo marked as "this is old, please do not use it"?
> What is a SwiftUI problem is the overall fragility of UI layouts. They fall apart in the most unexpected ways and at the most unfortunate moments. You can see it in the very real, production apps like UTM. It’s a fantastic piece of engineering, but its reliance on SwiftUI sometimes makes it feel like an early prototype.
This is an app written by someone who spends most of their time writing graphics APIs I think the fact that they can do something half-decent is really a testament to how approachable SwiftUI is
> In the end, you find yourself wrapping everything in a GeometryReader. And this is the ultimate admission of defeat.
No I only use GeometryReader when I actually want to do some coordinate math
> Okay, maybe you want to let your users customize the window toolbar, just as they could since 2001 (or something like that). Well, SwiftUI received this “breakthrough” feature only a few years ago.
iOS 14 my guy, this is literally one year after SwiftUI was released
> And then there’s the most basic task: displaying images you fetched from the network. Well, you better write your own fetcher, because AsyncImage was introduced only in iOS 15.
Can you point me at the API in UIKit that lets you do this?
> But if you want to also cache those images, I’ve got bad news for you: You can’t do it at all because right now, in July 2026, this API is still in beta.
Or this?
> For all these scenarios, developers usually come up with their own hacks and workarounds.
Yeah, it's called "you download one of a handful of libraries to do it for you". Now you don't have to do that.
Comment by formvoltron 17 hours ago
Comment by palata 16 hours ago
That is, pure native apps, can integrate KMP libraries. They cannot integrate Flutter libraries.
In other words, if I write a KMP library, I can ship it for multiple platforms and developers can use it in their Flutter project, or in their pure Android/Kotlin project, or in their pure iOS project.
Comment by rubymamis 17 hours ago
Comment by afidrya 17 hours ago
Comment by gen2brain 16 hours ago
Comment by preg_match 17 hours ago
If KDE can develop a high performance stable desktop, you can design whatever.
Comment by palata 16 hours ago
I don't know what your experience is, and I mean no offence or anything, but the only people I have seen who were happy with Qt for mobile development were people who had never tried to do it with a modern language, like Kotlin.
With Compose Multiplatform and Kotlin Multiplatform, you can write a cross-platform app in a modern language, and that is far better than C++.
Comment by danscan 17 hours ago
SwiftUI is good, albeit not without issues, as long as you tolerate them. The same is true for any approach. My most recent app was built in SwiftUI because I have been using React Native in my professional work for so long I wanted a change of scenery.
Each approach has its issues, and it all boils down to a matter of preference and which tradeoffs are appropriate for the project.
Comment by rumori 17 hours ago
Comment by ducktective 17 hours ago
Comment by palata 16 hours ago
All that to say, I don't think that vibe-porting will give you more than cross-platform. With cross-platform, at least your engineers understand the codebase.
Comment by krzyzanowskim 17 hours ago
Comment by randyrand 17 hours ago
Comment by frizlab 15 hours ago
Comment by SV_BubbleTime 17 hours ago
Comment by rumori 17 hours ago
Comment by livinglist 17 hours ago
Comment by lowbloodsugar 17 hours ago
Comment by lelandfe 17 hours ago
Comment by livinglist 17 hours ago
Comment by afavour 17 hours ago
Comment by zer0x4d 16 hours ago
1. It uses the builder pattern for views (familiar to those who used Java) but for some reason they decided to make it so that the order of the modifiers in the builder matters. Each modifier doesn't actually modify the main view but it modifies what the modifier before it decided to return. This makes no sense as the modifiers should each be modifying the main view to make everything predictable and easy to debug. I'm convinced no one (not even senior devs with 5 years of SwiftUI experience) understands how the ordering of modifiers works. It's just swap them until it does what you want it to.
2. The view lifecycles and code execution path seem random and hidden behind layers of "magic," making it incredibly difficult for developers to trace and debug issues.
3. It is practically impossible to set breakpoints for rendering and view construction, it's impossible to really figure out when re-renders happen and what drives them. I'm convinced SwiftUI apps are incredibly slow not because the SwiftUI implementation itself is slow, it's because, even Apple's own apps probably do a bunch of unnecessary re-renders and one no one seems to have any idea. This is unfortunately another design issue that can't be solved by just making SwiftUI more efficient. It requires simplification and tooling to help developers not footgun themselves.
4. Lots of issues start appearing later on in the development cycle because, for simple apps, bad SwiftUI design decisions and footguns have unnoticeable effects, until the apps gets more complex and things start breaking. Fixing these issues sometimes requires rewriting whole features or spending hours debugging.
5. There seems to be almost no documentation on Liquid Glass. It's laughable that after more than 1 year, Apple has simply refused to document or provide good examples for Liquid Glass, except for maybe couple pages that resemble the brain dump of an engineer that has never passed a writing class in college?
6. Stuff seems to be rapidly changing and breaking from version to version. It took days to make my app look and work the same in iOS 27 as it did on iOS 26, even though iOS 27 is supposed to be a minor bug fix release. We don't even use anything non-standard and don't do any hacks. This defeats the whole purpose of a simple UI framework that can be easily adopted to different platforms (this never used to happen with UIKit).
7. View debugger still has no SwiftUI equivalent. It used to make things so much simpler in UIKit when you could just see the view bounds, pick views apart and understand what's actually happening. SwiftUI has no equivalent other than `.background(.red)`. Terrible.
I don't know how Apple can salvage this beyond just undoing some of these terrible design decisions and making it 1. super simple to work with, 2. stop relying on magic, making things more explicit, and 3. providing actual 1:1 UIKit feature parity.
Comment by jshier 16 hours ago
2. Documentation issue. The lifecycle is standardized, but Apple is terrible as documenting it all in one place. I found this year's "Dive into lazy stacks and scrolling with SwiftUI" WWDC video actually had a pretty good explanation, at least for the lifecycle within lazy containers.
3 and 7. Yes, Apple's tools suck pretty bad. Preview canvas is also still terrible, despite multiple attempts to improve.
4. Not something I've experienced, not sure what you mean.
5. Yeah, Apple's docs suck.
6. Not sure what you mean here either, our stuff looks pretty much the same.
Comment by palata 16 hours ago
You mention some examples, I have experience with lower-level stuff: terrible. Poorly documented, and actually not really working well.
IMO they should focus on improving the developer experience instead of wasting money on the joke that is Liquid Glass (even users don't like it, right?). But anyway, too late for me: I'm soooo happy that I can develop iOS apps in Kotlin now, and just endure Xcode for building and occasional debugging.
Comment by a34729t 8 hours ago
Comment by mpweiher 16 hours ago
Comment by sandoze 16 hours ago
2. There’s no magic here. There is poor documentation. The biggest trick — small views, think about what values are going to trigger a refresh. Avoid cascading view refreshes.
6. You might have missed a couple big iOS releases (iOS 7 was one to remember) where many of our apps fell over in UIKit. Swift was another ‘DOA’ for YEARS with the same issues you’re making here, each new version broke the old, but here we are in a day and age where it’s the standard.
Comment by fenestella 10 hours ago
Comment by mpfh 7 hours ago
Comment by slopinthebag 10 hours ago
Swift feels impenetrable. So much syntax and features that are “progressively disclosed” (horrible UX paradigm btw) but instead just jump at you, breaking threading semantics, and horrible tooling. It’s also the only language I cant* get AI to perform decently well at, a double con.
I hate swift so much.
Comment by migueldeicaza 17 hours ago
Comment by migueldeicaza 17 hours ago
He is brute forcing his way through life and broadcasting it on YouTube.
Dunno man, Xogot is made up of almost half a million lines of code. Of those 727 files use SwiftUI, and 65 use UIKit, 119 use AppKit (I did not count the overlap, so they are not mutually exclusive).
Using GeometryReader makes it clear he is living in the past and the fact that he uses printChanges in this year without mentioning the dedicated SwiftUI instrument show a lack of curiosity on the space.
Comment by miffy900 6 hours ago
Comment by vintagedave 3 hours ago
He seems to phrase it as though he has to, that he falls back because nothing else works. What would you suggest instead?
I'm only lightly familiar with both Cocoa and SwiftUI, but I have heard many nightmare stories about SwiftUI and Swift the language. I'm inclined to take his criticism seriously, and I think there's a big distinction between people who know a platform very deeply -- you are a strong expert almost everywhere you touch :) and it's clear from your comment SwiftUI works for you -- and normal developers who, you know, just want to learn a framework once and use it to get a job done. Living in the past is not necessarily bad; it's a good thing if what worked in the past worked well and still works today.
Comment by lysace 17 hours ago
Comment by migueldeicaza 16 hours ago
Comment by mpweiher 17 hours ago
Comment by migueldeicaza 17 hours ago
In my professional medical opinion, he is at high risk of being replaced by a year old low-end Chinese open source LLM.
Comment by palata 16 hours ago
But now I feel like for most apps, I should be fine with Compose Multiplatform and Kotlin Multiplatform. I don't see the point of learning SwiftUI anymore.