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Comment by dimmke | Hacker News Reader

I just wanted to say thank you - I'm a web developer who has been learning iOS dev in his spare time and made the decision pretty early on to build my views programmatically.

It seemed crazy and old school to me to have the UI stuff that IB generates stored in XML - I definitely thought it should generate the same code that you would write to do it programmatically.

Also, the code for building UIs programmatically has been so unnecessarily complicated. Like building a collection view with all the functions needed and boilerplate code compared to the few lines we saw in the demo.

This seems so simple and declarative. It makes me feel a lot better about my future as an app developer. Thanks again!

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> It seemed crazy and old school to me to have the UI stuff that IB generates stored in XML - I definitely thought it should generate the same code that you would write to do it programmatically.

Most good ideas are old school. Data is more powerful than code because it can be analyzed in more ways - for instance, you can extract all the UI and text from an app, localize and re-insert it, then verify the UI won't break, all without having to execute the app.

If it's all in code you may not be able to get to some of the views or even know it's there. This is called the rule of least power - an example of getting it wrong is C++ iostreams.

Of course I'm sure SwiftUI has solved this.

Bullshit, any language with a macro system can do this. LISPs in particular are known for being code and data at the same time and this idea is way more old school than XML. You could also make a DSL that builds something like an AST of your UI in a similar fashion to free monads.

It's no surprise that XML seemed more attractive when your alternatives were Java or, even worse, Objective C. But really both options are absolutely terrible.

Thankfully we are very slowly making some steps forward again with Swift.

But we don't want the data and code to be the same, we want the data to be less dynamic than the code. You can't find out what the UI of a Lisp program would be without executing the program. It has everything available all the time, which is bad and turns you into a Lisp weenie.

SwiftUI is using new Swift features sort of similar to Haskell's "do" notation, which isn't actually itself monads.

Well the oldest ideas are around the notion that code is data and should be manipulated as such (from the 50s).

If you find iOS / macOS views cumbersome to write programmatically you should feel fortunate you didn’t have to write Android views programmatically.

True but who does this? The Android framework isn't built to support that reasonably at all, at least not until Jetpack Compose becomes viable.

Wasn't that the default way of doing things in Android? That is, build your ui's in XML?

By writing views programmatically in Android they mean writing them in Kotlin or Java, not XML. Almost no one does this.

Though Kotlin has an interesting looking DSL for doing that named Anko.

You can always create a layout XML file and inflate it. It saves tons of time. I can't imagine why you would do thing in code instead of inflating and attaching them.

Honestly, if not for SwiftUI, I find developing interfaces in Android to be infintely faster than either fighting Apple's Interface Builder or building things by code in Swift.

> It seemed crazy and old school to me to have the UI stuff that IB generates stored in XML - I definitely thought it should generate the same code that you would write to do it programmatically.

Well you know, Cocoa and its predecessor OPENSTEP were built on the idea of using IB to compose interfaces out of actual objects that then got "freezed" into a file. So, no code at all, that was the idea.

Building views programmatically was the old school way even back then. ;)

And the IB approach is a nice one, except that its files (whether NIB or XIB) simply don't diff as nice as the equivalent in code. Checking changes into source control is an opaque experience as the diff is an endless vomit of unintelligible mumbo.

What is so astonishing about SwiftUI is that it's simultaneously the most impressive looking visual GUI builder I've ever seen... and the most terse, diff-able syntax I've ever seen. I can't think of anything that has combined these two properties quite so successfully.

> It seemed crazy and old school to me to have the UI stuff that IB generates stored in XML - I definitely thought it should generate the same code that you would write to do it programmatically.

The idea behind Interface Builder is that it writes the class instances and their properties using NSCoding, and they're decoded at runtime and assigned to your IBOutlets just as if you had initialized them in code, set their properties, and assigned them to instance variables yourself. XIBs were introduced with OS X Leopard as a text-based way to store the files in source control, but they're still compiled into binary NIBs when the project is built. You're not supposed to hand-edit the XML.

So I've been working with SwiftUI for the past day and I am completely blank on how one would implement a collection view, like one with multiple rows. I did succeed to do it myself with a VStack and multiple HStacks, inside which I basically put the cells. Did they show this in the demo or was it a one-dimensional collection view?

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