Xcode14 on dev.endevour

Sharing is caring

Sat, 10 Dec 2022 00:00:00 +0000

Continuing on with the demo project from yesterday, in which we used the ImageRenderer class to turn a view into an image, today we want to let the user share it somehow.

Typically, apps have a button using the square.and.arrow.up SF Symbol to share something from the current screen. It’s probably not an accident that it’s literally the first symbol in the app.

Pressing it generally opens the “share sheet” which has options for opening whatever is being shared in another app, printing it, saving it to photos, or whatever.

Console spam - No wall clock alignment

Wed, 16 Nov 2022 00:00:00 +0000

When I was working on the Day 60 app, I noticed I kept getting a message in the console “No wall clock alignment provided at SwiftUI/ResolvableStringAttribute.swift:86” every time I went into the detail view. Via elimination by commenting bits out, I’ve narrowed it down to a date formatting call. Here is the code to reproduce it in Xcode Version 14.0.1, Swift 5.7.0.127.4

struct ContentView: View {
 var body: some View {
 Text("Date: \(Date(), style: .date)")
 }
}

It’s to do with the style - if I change it to .time or .relative the message does not appear.

FriendFace

Mon, 14 Nov 2022 00:00:00 +0000

The Day 60 Milestone is a demo app that vacuums up some JSON and displays it in a list in a NavigationView that links to a details page. Nothing super strenuous, the steps were something like this:

Download the JSON and have a look at the structure. Firefox has a simple JSON viewer built in, so it was straightforward to see this is an array of users, which along with some (mostly string) properties contains an array of tag strings, and another array of friends.

Project 12 Challenges

Thu, 10 Nov 2022 00:00:00 +0000

Project 12 was a series of code tutorials around developing CoreData concepts rather than a real app, but the challenges are based on a very small app that uses a subview to allow dynamic (ie changeable at runtime) filtering of a list of data. The reason this would be tricky is that the @FetchRequest is a property of a view - and therefore mutable. The trick is to have a subview to build that part of the view, and to pass parameters into it which build the fetchrequest using an underscore.

Bookworm Feedback

Mon, 07 Nov 2022 00:00:00 +0000

I did so well on this one that it’s not going to make a very interesting post. My first two challenge solutions were pretty much character for character the same - so not much to report.

On the third challenge, there was a minor difference in the display process. I had done this:

let date = book.date ?? Date()
Text(date.formatted(.dateTime.day().month().year()))
 .foregroundColor(.secondary)
 .opacity(date == book.date ? 1 : 0)

But @twostraws went:

Bookworm Challenges

Sun, 06 Nov 2022 00:00:00 +0000

Another set of challenges for a #100DaysofSwiftUI tutorial app. Project 11 was a book tracking app - the big new thing was using CoreData. Here’s the challenges for it .

Right now it’s possible to select no title, author, or genre for books, which causes a problem for the detail view. Please fix this, either by forcing defaults, validating the form, or showing a default picture for unknown genres – you can choose.

CoreData and the Preview

Fri, 04 Nov 2022 00:00:00 +0000

I’ve noticed Paul is inclined to ignore the preview and run his code in the simulator to check its operation. That’s valid, but it seems quicker, and reassuring, to see it in the preview as I type.

This led to a small problem with Day 53 that uses CoreData. When I added a student in the preview, it looked like this, and was immediately followed with a crash report.

Cupcake Corner Feedback

Thu, 03 Nov 2022 00:00:00 +0000

As usual, here’s my thoughts comparing my attempts at the challenges to Paul’s. Usually he’s better!

1) Whitespace

The task was to validate the order address properties, not just by checking they are not empty, but also that they don’t just contain spaces. I went the bruteforce route since there was no .isEmptyIncludingWhitespace method.

var hasValidAddress: Bool {
 let trimmedName = name.trimmingCharacters(in: .whitespacesAndNewlines)
 let trimmedStreetAddress = streetAddress.trimmingCharacters(in: .whitespacesAndNewlines)
 let trimmedCity = city.trimmingCharacters(in: .whitespacesAndNewlines)
 let trimmedZip = zip.trimmingCharacters(in: .whitespacesAndNewlines)

 if trimmedName.isEmpty || trimmedStreetAddress.isEmpty || trimmedCity.isEmpty || trimmedZip.isEmpty {
 return false
 }
 return true
}

As soon as Paul mentioned extending String, I facepalmed - of course, just create the method I want on string. Paul’s is a one line extension - neater, and Swiftyier.

Cupcake Corner challenges

Wed, 02 Nov 2022 00:00:00 +0000

Day 52 of #100Days was the challenges to the Cupcake Corner app - an app that allows you to build a one-row order, encode it as JSON and submit it to an API with a URLSession. To allow the order to be passed around, it’s an @ObservedObject which meant that a few extra hoops needed to be jumped through to make it Codable.

1) Whitespace validation

The tutorial app validates the order address by checking that each field is not empty, but it can be fooled by just entering some spaces. The first challenge was to fix that.

Day 50 - @State vs @Observed again

Fri, 28 Oct 2022 00:00:00 +0000

Way back when, I was unclear about @StateObject and @ObservedObject (here , and here ). I still am.

But in today’s tutorial video, Paul clearly says that the @StateObject is for the single place in your app where the object is created, then everywhere else, use @ObservedObject. Trouble is, I just know from the Simple MVVM app I made if you wrap the single instance of the data model with the @ObservedObject, it still works.

Day 47 - Habits App

Thu, 27 Oct 2022 00:00:00 +0000

I’ve been mucking around with the Habits app too long - it’s started to look like procrastination. It already meets the specification , so I’m calling it an MVP and moving on.

This is the first app of mine I’ve loaded onto my phone and started using, and there are a couple of things I’d like to do with it. It currently just lets you specify how many days between an activity repeating - so if you say you should go to the gym every second day, and you complete that activity on Monday, “Gym” will make it’s way to the top of the list on Wednesday. While it’s waiting in the list for Wednesday to come around, it will show the “Due” time as being exactly 48 hours after you last pressed “done” on it. But if the habit you want is to go to the gym after work at 6:00pm that’s when you want it to be due. I’d like that.

Why?

Wed, 26 Oct 2022 00:00:00 +0000

Why do I have to resize this preview window every time I open Xcode?

JSON encode/decode

Mon, 24 Oct 2022 00:00:00 +0000

As usual, I’m spending way more time on the apps written from scratch in the 100Days series . The Habit tracking app I’m working on has been good practice, especially of the architecture of the simple list based app .

My version has a couple of refinements I quite like. I’m using a checkmark in a rectangle as the button to mark that activity as done, and I’ve added a nice fade to the checkmark as time goes on to represent the percentage of time from when it is done until it becomes due again.

Refreshing SwiftUI Views

Sun, 23 Oct 2022 00:00:00 +0000

SwiftUI does some property wrapper magic to (very efficiently) refresh your views, but what if you want to force a refresh for some reason? Here’s the techniques I’m currently using to do that.

The tricks are below, but just so you can see them in context, here’s the sample app we’re working on. It’s a list of cars so you can keep track of how many of each kind you own. Here’s our data:

You need to enjoy puzzles

Sat, 22 Oct 2022 00:00:00 +0000

I’m writing the Habits list based app from #100Days and had a working MVP, then for some reason, decided to refactor by changing the subview I’d written as a function, into a struct. Some time later, I discovered that my list items were not updating correctly, so detective time.

I talked a little bit about the architecture yesterday - the item is a struct, and there’s a class containing an array of the items. Something like this:

Purple warning - "Publishing changes"

Fri, 21 Oct 2022 00:00:00 +0000

It’s a pretty safe bet that if Xcode is saying there’s an error in my code, that it’s correct, and I am in error - not Xcode. Today I came across a situation where that might not be true.

I think the purple warnings are problems detected at runtime - I’ve heard of thread problems causing purple warnings. The error I was getting was “Publishing changes from within view updates is not allowed, this will cause undefined behavior.”

Drawing Feedback

Wed, 19 Oct 2022 00:00:00 +0000

Here’s the summary of my learning from comparing my efforts with Paul’s solutions to the Project Nine challenges from Day 46 of his 100 Days of SwiftUI course .

Create an Arrow shape – having it point straight up is fine. This could be a rectangle/triangle-style arrow, or perhaps three lines, or maybe something else depending on what kind of arrow you want to draw.

Project 9 - Drawing

Tue, 18 Oct 2022 00:00:00 +0000

These few days of #100DaysOfSwiftUI we made some pretty shapes by playing around with some of the SwiftUI systems for drawing on the screen, including paths, shapes, transformations, ImagePaint, drawingGroup() to use Metal rendering, blurs, blend modes and using animatableData for animating - which I think is the solution to an animation problem in my TimesTable app I hadn’t been able to solve yet.

When it Works

Mon, 17 Oct 2022 00:00:00 +0000

The little joy of something working. It’s one of the things that makes coding enjoyable. Like a good video game you have an overarching goal, but on the way you need to solve a large number of problems of variable complexity, and you get a little bit of dopamine for each one.

I think in every language I’ve ever learned, as soon as I know how to draw something on the screen, I start to get the urge to create a simple drawing application. When I was starting on Visual C++ and the MFC (Microsoft Foundation Classes) the book I used to get started built a drawing application as an example. It hooks into the benefit of being able to quickly see the evidence you’ve achieved something.

Moonshot Feedback

Sat, 15 Oct 2022 00:00:00 +0000

I’ve watched Paul’s solution to the Moonshot challenges (the solutions are one of the perks of being a Hacking With Swift subscriber). When I’m solo learning like this its one of the few ways I can get any feedback on my coding, so I highly value it, and usually write one of these posts as a way to ensure I reflect on it.

Moonshot Challenges

Fri, 14 Oct 2022 00:00:00 +0000

Another few coding challenges at the end of a tutorial app in the 100 Days of SwiftUI course. The app is a sort of information app - composed of navigation views going down into more detail about the Apollo space missions. The most exciting revelation for me was how straightforward it is to pull JSON into your apps data structures.

Challenge 1

Add the launch date to MissionView, below the mission badge. You might choose to format this differently given that more space is available, but it’s down to you.

iExpense Feedback

Wed, 12 Oct 2022 00:00:00 +0000

I finally got around to looking at Paul’s solutions for the iExpense challenges .

Use the user’s preferred currency, rather than always using US dollars.

Same approach as me,

.currency(code: Locale.current.currency?.identifier ?? "USD")

except that he does the work in a local variable which is a bit neater. Since it appears in two places - the display view and the view for adding an expense, this would mean duplicating it, making it global (not rare for user default type settings) or passing it down through the view hierarchy. I feel either of the first two options are fine for this project, but Paul is thorough and extends the FormatStyle protocol, only for currency, to have a new computed property .localcurrency - which is a great solution.

SwiftLint

Mon, 10 Oct 2022 00:00:00 +0000

I was watching a Tim Ruscica video about the things that highly effective developers do, and it called to mind a book I read years ago called Code Complete . It is the only book I ever owned that I immediately purchased the new edition when it came out. It was about the meta stuff around programming that is the difference between coding and developing. In particular, it got me invested in source control and testing.

Testing, testing

Sun, 09 Oct 2022 00:00:00 +0000

I have unit testing in my list of goals , and if I’m going to throw this space trimming macOS utility up on the web, now might be a good time to figure out how to add unit tests to a project, how to write them, and how to run them. XCode is well set up for this, so it’s really no drama to do.

Although I haven’t worried with any unit testing up to this point in my iOS/Swift learning, in my previous programming work I did a lot of work with the large calculations involved in translating GPS coordinates and robotic positioning models where errors would be bad - so I’ve written a lot of tests over the years. I’ve also definitely felt the confidence you can dramatically refactor code with when you know the code has a robust test suite. I’m a big fan.

Where's My App?

Sat, 08 Oct 2022 00:00:00 +0000

The iOS apps I’ve been making, can only run in the simulator or on my tethered device (which I haven’t actually tried yet), but the MacOS app I made today, in theory could be zipped up and distributed to the world from my website. At the very least, I wanted to drop it into my Applications folder so I could use it, so I needed to find the .app “file”, and realised I had no idea where it was. If that’s your situation, then here’s the steps you need.

Customizing the default About dialog for MacOS apps

Fri, 07 Oct 2022 00:00:00 +0000

The default Xcode MacOS targeted app has a built in “About” dialog called up from the “About ” menu item in the Mac menu bar. It wasn’t immediately clear to me how to customise this, but after digging through some MacOS apps on GitHub, here’s the answer.

When you app is being built, it looks for the file “Credits.rtf” in the app bundle. If that is found (or “Credits.html” or “Credits.rtfd” ) it’s used to build out the About dialog along with your app icon.

CodeTrimmer - First MacOS App

Thu, 06 Oct 2022 00:00:00 +0000

I was listening to the StackTrace app this morning (episode 169 - “Choosing What Bugs to Ship” ) and one of the ideas discussed was taking the time to automate some of your development processes, partially to save time, but also because if you make a process simple and quick, you’ll be more likely to do it multiple times to improve quality.

Coincidentally, I’d been thinking about how often I paste some code from Xcode in order to display it in one of these blog posts. If it’s from the middle of a method, it will generally be indented a long way in, and there’s no point in displaying it like that (especially for a mobile reader) so I usually manually delete a heap of spaces from each line to left align it whilst keeping the needed indentation.

Design Challenge

Wed, 05 Oct 2022 00:00:00 +0000

So, I’ve been working on translating the UI design created by the external designer into SwiftUI, and have done all of the easy bits:

The rounded rectangles for things like the question display/number input are just ZStacks of roundedrects filled, then stroked:

ZStack {
 RoundedRectangle(cornerRadius: 10)
 .fill(.white)
 .padding(.horizontal)
 RoundedRectangle(cornerRadius: 10)
 .stroke(.black, lineWidth: 2)
 .padding(.horizontal)
 HStack {
 Text(questionText)
 .font(.title)
 .fontWeight(.heavy)
 Text(calculatorDisplay)
 .font(.title)
 .fontWeight(.heavy)
 .foregroundColor(.blue)
 }
}
.frame(maxWidth: 350)
.offset(y: 15)

Something I have learned in the process is the .offset modifer. This is what’s used to move a view from where SwiftUI would have placed it, and is what I’ve done to create that overlapped style where the question display/number input is sitting halfway over the bottom of the blue rounded rectangle. This is in the last line of the code above: .offset(y: 15) This is moving the whole ZStack down by 15. A trick to watch with this is that since you’ve messed with SwiftUI’s arrangement, it doesn’t then shuffle everything else around this - you need to manually deal with making some space below it.

iExpense Challenges

Sun, 02 Oct 2022 00:00:00 +0000

Day 38 is three challenges on the iExpense app - a simple expense tracking app that uses UseDefaults for storing it’s data.

Locale

Use the user’s preferred currency, rather than always using US dollars.

One of the joys of modern programming (as opposed to mid-1990’s programming) is the ability of the internet to give you answers. I knew the answer to this would be lurking in the locale environment variable, but instead of looking it up , just googled, and found a viable looking solution on Reddit .

Times Tables -Day 35 Challenge

Sat, 01 Oct 2022 00:00:00 +0000

The challenge for Day 35 of 100 Days of Swift UI was to create a simple times tables drilling app. I’ve met all the requirements, so I’ll move on, but I am struck by how ugly it is. Making better looking apps needs to be added to my goals. Especially since this app is intended to appeal to children, and is at the end of a few lessons on animation, this is definitely a weakness of mine at the moment.

Gitting Xcode to Push

Fri, 30 Sep 2022 00:00:00 +0000

I’m very comfortable with doing all the routine git stuff from the command line, but it was bugging me that I hadn’t for the Xcode integration working. I was able to commit locally with no problem from Xcode, but could not push up to Github. It works fine from the command line, so the error about the change to a stronger SSH authentication didn’t really make sense to me.

User Defaults & Horizontal Pickers

Wed, 28 Sep 2022 00:00:00 +0000

I’m on the challenges for Day 35 of 100 Days of SwiftUI , and despite Paul’s very clear warning:

Important: It’s really easy to get sucked into these challenges and spend hours…

I have spent ages fiddling around, but of course still learning. My issue is not so much getting stuck on bugs, rather I keep wanting to do things I don’t know how to do.

One issue was solved for my by the wonderful Fireside Swift podcast. I’m working through the old (Steve & Zac) episodes, and they did one on the UserDefaults just when I wanted to be able to persist the multiplication table selection the user had made (this challenge app is a multiplication tables drill app for kids).

Animating Guess The Flag

Sat, 24 Sep 2022 00:00:00 +0000

The challenges for Project 6 of 100 Days of SwiftUI was to add some animations to the Guess the Flag app from a little while ago. The animations themselves were not particularly tricky, my main issue was that I was creating the views for the three flags in a ForEach, so the animations were applied to all three flags, but we wanted different animations for the flag the user had clicked versus those they had not.

Animations in Views

Fri, 23 Sep 2022 00:00:00 +0000

It’s a very Apple-thinking thing to be learning about making beautiful and intuitive user experiences this early in a programing tutorial as I am with the 100 Days of Swift UI series. Here’s a quick look at three different ways of doing animation in SwiftUI Views.

Implicit animation

An implicit animation in SwiftUI is when you add a .animation() modifier to a view. It needs to be bound to the value that’s changing so the framework knows to animate when that value changes, and the nature of the change.

Don't Use Stupid Project Names

Thu, 22 Sep 2022 00:00:00 +0000

I’m up to Day 32 of 100 Days of Swift UI, and although the tutorial is named “Project 6” it’s not really a project that becomes a simple app, it’s really just a series of tutorials on animation that I assume the techniques, but none of the code, will be used later in apps.

I do find there’s some value in typing in the code (rather than cutting and pasting, or just passively watching) so I opened up Xcode to follow along. There not being an app name offered, I used “Project 6 - Animation”. XCode seemed happy enough with that, and created the directory and placeholder, but then refused to build it saying there was seven errors involving the __PACKAGE_NAME macro and a missing }

Recording the Simulator

Wed, 21 Sep 2022 00:00:00 +0000

I’ve been using Quicktime to screen record the preview or simulator to document my work here and in Github ReadMe’s, but thanks to this excellent short post by Sarun W , I now know it’s possible to do that directly from the simulator, including capturing gestures, and exporting to animated gifs!

Changing Xcode Font Size

Tue, 20 Sep 2022 00:00:00 +0000

I’ve been changing the Xcode font size by going into the preferences, themes, then selecting the different content types and changing the font size.

I guess I could speed that process up by saving some themes with different text sizes, but I’ve noticed a few times in tutorial videos that there must have been an easier way. It turns out that Ctrl + “+” and Ctrl + “-” increases and decreases the code font size.

Project 5 - Word Scramble

Mon, 19 Sep 2022 00:00:00 +0000

Another 100 Days of Swift UI project wrapped up - this time a scrabble like word game. New techniques included saving a large text file in the app bundle and loading it (via a string) into an array on launch of the view. Also a short adventure into UIKit to use a UITextChecker.

Source .

Word Scramble Feedback

Mon, 19 Sep 2022 00:00:00 +0000

As is my practice now, after completing the challenges for Project 5 , I reviewed Paul’s solution (which is only available to subscribers) to see what he’d done better so I could learn from it.

Most of the differences where not of much significance, but there was a couple of things I picked up:

When the user had pressed the reset button, to empty the array of word guesses from the previous turn, I had