Tag Archives: update

This Old App: Hooking up the Model

A few months ago, Apple removed my app Interval RunCalc from the App Store for being too old and not updated. In this series of articles I’ll document what I did on rebuilding and improving the app. In the last installment, I hooked up my picker view interface to my app, and built the first round of user interfaces, along the way finding I’ve painted myself into a corner a few times and made several really silly mistakes.  In this installment, I hook up the model so the app actually calculates something – and get a pleasant surprise.

Hook up the Model

Up to now I’ve been setting the initial data to the picker as a literal. For example in the time entry

@IBAction func timerEntry(_ sender: UIButton) {

    if runStats.locked != .time{

      let vc = storyboard?.instantiateViewController(withIdentifier:>"InputController") as! PickerViewController

      vc.delegate = self

      vc.units = .hoursMinutesSecond

      vc.value = 4283.0// in seconds 3600 + 600 + 60 + 20 + 3 = 1 hr 11min 23sec

      vc.modalTransitionStyle = .crossDissolve

      present(vc, animated: true, completion:nil)



I set the picker to always get a 1:11:23 time. I’m going to change this to the RunStats model.

Before I do this, I notice an error I missed up to now. I have timerEntry instead of timeEntry. It’s a little thing, but it affects documentation, so I’ll fix it. Since this is an action, I unconnected the action, changed the spelling, cleaned with Command-Shift-K and then re-connect it.

Once I do that, I change the value to the runStats value for time, based on the model I created a few installments ago.

vc.units = .hoursMinutesSecond

vc.value = runStats.time.seconds()

I’ll do this next for distance, which is a bit more complicated. Each of my stats in the model has a value, which has a getter for the correct units(Kilometer or mile), and a enum for the correct units for display. The picker does too, but the enum is a different type, and the value is a generic Double, getting all the unit information from the enum. I create a switch statement to convert from the model to the picker.

      switch runStats.distance.displayUnits{

      case .kilometers:

        vc.units = .kilometers

        vc.value = runStats.distance.kilometers()

      case .miles:

        vc.units = .miles

        vc.value = runStats.distance.miles()


For pace I should have the same thing, but there a wrinkle. The picker requires a Double for all measurements. In the model I have a string for minutesSecondsPerMile. The picker is looking for a double of seconds per mile, which I don’t have in PaceStat.  In the PaceStat class, I defined that string like this:

  public func minutesSecondsPerMile() -> String{

    let secondsPerMile = 1609.344 / paceStat

    let minutes = Int(secondsPerMile) / 60

    let seconds = Int(secondsPerMile) % 60

    return String(format:"%02i:%02i",minutes,seconds)


Since seconds per mile was a necessary calculation to create the string, this is an easy fix. I can break that method into two methods:

func secondsPerMile()->Double{

    return 1609.344 / paceStat



func minutesSecondsPerMile() -> String{

    let minutes = Int(secondsPerMile()) / 60

    let seconds = Int(secondsPerMile()) % 60

    return String(format:"%02i:%02i",minutes,seconds)


Then add to the paceEntry action in my view controller this switch to convert units and values for the picker.

switch runStats.pace.displayUnits{

case .kilometersPerHour:

  vc.units = .kilometersPerHour

  vc.value = runStats.pace.kilometersPerHour()

case .milesPerHour:

  vc.units = .milesPerHour

  vc.value = runStats.pace.milesPerHour()

case .minutesSecondsPerMile:

  vc.units = .minutesSecondsPerMile

  vc.value = runStats.pace.secondsPerMile()


The Locked Value

Next I’ll add calculations for the locked value. This was the big surprise. I’ll add this to the RunStats model:

func recalculate() {

    switch locked{

    case .distance:

      self.distance = distance(pace: pace, time: time)

    case .pace:

      self.pace = pace(time: time, distance: distance)

    case .time:

      self.time = time(pace: pace, distance: distance)




There are times when one over-analyzes a situation, and leads to a complex solution. I did that in version 1.0 with the calculations above. Because I planned out the model so carefully for V 2.0, this ends up incredibly easy to deal with. In the V1.0 model, I was basing things on what changed, not what was locked. Locked is my solution, not just a locked variable. It the difference between “Pace just changed! What do I do?” to “Solve for time given pace and distance” The second is a lot simpler to think about and code.


I’ll make sure I have some starting data in view did load

override func viewDidLoad() {


  runStats.pace = PaceStat(minutes: 10, seconds: 00)

  runStats.pace.displayUnits = .minutesSecondsPerMile

  runStats.distance = DistanceStat(miles: 26.2)

  runStats.distance.displayUnits = .miles

  runStats.locked = .time

  runStats.time = runStats.time(pace: runStats.pace, distance: runStats.distance)



I’m ready to build and run. I’m pleasantly surprised that the first run works perfectly. The initial value loads from the model.

This is my ultimate goal for a marathon: a 4:22 finish. That’s way in the future – I’ve never run more than a half marathon. I try my last 5K run to find pace, changing the distance units, and solving for pace.

Yeah, I got a lot of training (and weight loss) ahead of me. My last long run used a slower combination of run/walk so it looks like this:

I have a ten Mile race coming up based on those paces, I can calculate My time between 2:24:50 and 2:16:50.

All of these match data calculated by other apps, so it looks like the app is working. For a change, I don’t have a lot of work to do in a development stage. I just plugged things in and they worked. I know it is supposed to work when I plan things out carefully, but it still amazes me when it does. I’ve done too much debugging to believe something actually works right the first time. In the next installment, I’ll start adding another level of complexity and that might change. I’ll start adding the interval table. First part of that phase is making a custom table view cell.

This Old App: 2013 Code, Meet Xcode 8

A few months ago my app Interval RunCalc was removed from the App Store for being too old and not updated. In this series of articles I’ll document what I did on rebuilding and improving the app. In our first article I analyzed the changes necessary. In the second, I built the model in a Swift playground. Now it is time to place that model into the old app, and make a temporary view and controller to test it.

Open the App in Xcode

I made a copy of the original app development files, then opened them in Xcode. The issue navigator started complaining right away:

Clicking on the issue, I find several updates Xcode wanted to make.

I select Perform Changes resolving the issues. I find in the target settings for the project, there’s more issues: provisioning profiles for debug and release.


Above the issue, I’ll find a checkbox Automatically Manage Signing. I check that and enable the automatic signing.

I find provisioning one of the most irritating parts of working with Xcode. Anything to get me away from it is a good thing.

Of course that’s not the end of the issues. I get another error message.

If I manage singing automatically, I have to pick the team. I only have me so I pick myself from the drop down. The target is set up, and Xcode is happy again.

Configuring the New Version

This is a major version update for the app. I want to change the version number to version 2.0. Originally I wanted the app to be called runner’s calc, but that name was taken. I settled on the mouthful Interval RunCalc. That’s too long for an icon, I want to change the Display Name to a shorter name, Run Calc to show better on an icon.

The next change I’ll make is the deployment info. Currently, the deployment is iOS 8.0 and only on iPhone in portrait.

Which iOS version to set to is a good question. In most cases, you want to deploy a version or two back for compatibility. Here’s where getting user data comes in handy. I’ll use iTunes Connect’s analytics, and look at the analytics for 2016.

Two active devices per month means there’s almost no one but me using this. Usage data strongly hints me that the biggest user is me. The large peaks occur at races I either ran or was a spectator (marathons are my 2018 goal). While a second user might be at the same races, I find it unlikely.

I’m looking at a sample that’s less than a third of total apps out there. Still, upping the version to 10.3 is not tragic since it looks like nobody but me uses this. I’ll bump it up all the way for the revision. I’m also going to make this a Universal app instead of a iPhone app. My new settings look like this:

Later, I’ll set the iPad and iPhone interface to the same initial storyboard.

The Old Structure

Opening the project navigator, You can see how I put together this app:

You’ll see the root files are the RunnersCalc files. The top level contains the initial view controller and the help controller. There was a help controller, though no one knows how to get to it — I unfortunately hid it too well. If you got to it, it was just written instructions, and very badly written. It’s another thing to go on the list of changes.

The folders under this root level has one folder for the model, and three folders for the view controllers: Intervals, Input controls and Splits.

For those from a completely Swift background, those .h and .m files are Objective-C files. The .h files contain a header which indicates what properties and methods are sharable to the rest of the app. Your code is in the .m files.

Opening up the Model folder and clicking the PCPace.h file, I find the declarations for the model, the properties of the model were:

//properties of the object

@property NSTimeInterval pace; // seconds per mile

@property float speed; // miles per hour

@property float distance; //miles

@property NSTimeInterval time; //seconds of the run or split

@property NSTimeInterval splitPace; //seconds per mile or km

@property int splitCount; //total number of splits

@property int splitNumber; //current split -- necessary?

@property int fullSplitCount; //number of splits for the full mile/kilometer

@property NSTimeInterval elapsedTime; //elapsed time in a split

@property float totalDistance; //totalDistance to this point

enum PCVariable {



@property enum PCVariable finding;

Add the Playground Code to the App

I’m not too worried about any of this code, since I’m about to replace it all. I open up the RunStats playground so I can copy my code. I have the code stored in four files:

In the App project, I’ll make four new files in the model folder. I’ll select the Model Folder first to keep the group correct as I add files. I’ll hit Command-N to make a new file. There’s several ways I can make these files, since I’m cutting and pasting everything into the file. I’ll select Swift File for the template, though I could have just as easily picked a Cocoa Touch Class subclassing NSObject.

I’ll be asked to save with a file name. I’ll call this one RunStats.

On the bottom, I’ll make sure the target is correct and the Group is Model

We click Create, and get a new Message:

I usually create the bridging header. As the message says the bridging header opens up the classes, methods and properties in the Objective-C code to the the newer Swift code if you want to use it. In this application I won’t use it. However, it is not a lot of overhead. I’m planning to scrap all the Objective-C, but I never know in an intermediate step if I’ll need it, so I’ll create it anyway.

I’ll repeat this three more times for the classes DistanceStat, PaceStat and TimeStat. I have two classes in the RunStats playground page. I’ll add one more for RunStatsIntervals, so every class has its own file.

I’ll organize this a little better. I’ll select my Objective-C files PCPace.h, PCPace.m, and the bridging header. I’ll right click and make New Group From Selection, naming the group Objective-C. I’ll do the same for the Swift code, selecting it all and making a Swift group for it.

I’ll select RunStats, and see this:


// RunStats.swift

// RunnersCalc


// Created by Steven Lipton on 4/6/17.

// Copyright © 2017 Steven Lipton. All rights reserved.


import Foundation

I’ll delete the import foundation, and then copy and paste my RunStats class from the playground to the App, leaving the intervals class and the test data in the playground. I’ll make sure I copy the import UIKit when I do. It will of course have lots of errors for the moment. We have the three classes it refers to yet to add. I’ll do the same copy and paste to the other four files, adding the classes and import UIKit in each case.

Once I’m done with this there are seven issues to solve. When transferring a playground, you’ll probably get these errors.

If you click on the first error, it will show you this in the editor:

The time.seconds() and the distance.meters() lines Xcode wants to assign to something. I used them to get a quicklook for debugging the playground. All the errors are like this. The simple solution is delete that code. The fatal error is the same thing. it’s on the line


It was to get a quicklook for the object in the playground. I deleted it to clear the error.

A New View and Controller

The new model is in the app, and I’d like to test it. Right now, this code is ignored by the app. What I’ll do is set up a new storyboard to check the model. In the Storyboards group, I have a blank iPad storyboard and the Main_iPhone.storyboard file, which has the current storyboard for the app:

This is a big mess. This is one of those times when doing an update project like this you just shake your head and wonder what you were thinking back then. With a little investigation, you’ll find some of those answers. I iterated this model with a inadequate model to start, and I needed a lot of UI to cover up my mistakes. The major reason this app never had an iPad version was I’d have to replicate this storyboard on an iPad.

The new app had a completly new Storyboard. I’m using auto layout to need one storyboard for all devices. I Press Command-N, selecting a Storyboard object and name it Main, making sure my Group is Storyboards.

The storyboard I get is completely blank. I’ll drag a view controller onto the storyboard

I’ll change the attribute to give this a name and set this view controller to Is Initial view controller.

I’ll need a ViewController file for this scene. I’ll press Command-N again, click a Cocoa Touch Class for the template and make the Class RootViewController, subclassing UIViewController and Swift as the language.

When I save the file I’ll save it to the RunnersCalc root folder, where the root and help view controllers are. Going back to the main storyboard, I’ll set the Custom Class to RootViewController. Now I’m ready to add some controls.

This first layout is only for testing purposes. No auto layout just yet, just drag and drop. I’ll add a label for a result and a button to calculate the result. I’ll use text fields for input, so I’ll need room for the keyboard.  I’ll set the button at the center of the iPhone screen, giving the keyboard I hope plenty of room, and the result at the top. I’ll make the label read Result and the button Calculate

I Drop two text fields between the label and the button, which I’ll call variable 1 and 2. That will be for decimal values. For time values I’ll add three textfields under those two text fields. The layout looks like this, using placeholder text for titles.

Next, I’ll wire up my view controller. I’ll open the assistant editor. All but the button are outlets, So I’ll do those first, control dragging into the view controller.

@IBOutlet weak var result: UILabel!

  @IBOutlet weak var variable1: UITextField!

  @IBOutlet weak var variable2: UITextField!

  @IBOutlet weak var hours: UITextField!

  @IBOutlet weak var minutes: UITextField!

  @IBOutlet weak var seconds: UITextField!

I’m keeping this very generic for a reason. This is a test bed. I’ll use these same fields to check different parts of the model. I’ll calculate the values in code in the calculate button, which I now wire up as an action.

@IBAction func calculate(_ sender: UIButton) { 


There’s a function I’ll need in the view controller. It will take a TextField and convert the text in it to a Double. I can close up the storyboard and assistant editor, and then add the function to RootViewController

  func double(textField:UITextField!)->Double{

    guard let textField = textField 

       else {return 0.0} //uwrap textfield

    guard let value = Double(textField.text!) 

       else {return 0.0} //find double

    return value


This will give me a value of 0 for anything that isn’t a true Double, and return a Double if it is. There’s three optionals, and I deal with all the unwrapping here giving me a value or a zero. This is not something I’ll need in the finished code. The input system (which we cover next time) will restrict the user to only valid values.

With the structure of the test bed done, I’ll add the model to the code.

 let runStats = RunStats()

I’ll test the function the IBAction calculate. I’ll start with a simple test to make sure everything works, converting kilometers to miles.

@IBAction func calculate(_ sender: UIButton) {

    let distance = double(textField: variable1)

    runStats.distance.distance(kilometers: distance)

    let resultText = String(format: "%02.2d", runStats.distance.miles())

    result.text = resultText


I use the double function to turn the variable1 text field into a double, then add it to the model with a kilometer measure. I change the distance to miles in a string, placing the result in result.

I’m almost ready to run this code, but there’s one more thing I need to do: Change the initial storyboard. In the General tab of the Target Properties, you’ll find this:

When run, the app goes to the old Main_iPHone storyboard, not the new Main. I also restricted the layout to portrait in the old version, and I’ll use all orientations for the new version. I set both the iPad and iPhone to the same storyboard Main:

Setting my simulator to an iPhone 7 I run the app. Two things happen. I get 44 warnings, but the app runs. I try putting in a value. I find I didn’t leave enough room for the keyboard

I’ll stop the app and move the calculate button up. I try running again. I’ll type in 5 when the calculator appears, and get rewarded with a value of…Zero instead of 3.11.

I first check to see if the model is working right with a few print statements

@IBAction func calculate(_ sender: UIButton) {

    let distance = double(textField: variable1)

    print("distance in km \(distance)")

    runStats.distance.distance(kilometers: distance)

    print("distance in km \(runStats.distance.kilometers())")

    print("distance in km \(runStats.distance.miles())")

    let resultText = String(format: "%02.2d", runStats.distance.miles())

    result.text = resultText


When run, I get output on the console:

distance in km 5.0

distance in km 5.0

distance in km 3.10685596118667

The model is working fine. My bug is a silly one of setting the format wrong in the string. I change the format to this:

let resultText = String(format: "%6.2f", runStats.distance.miles())

When I run again, the test works.

I go back to the storyboard. That alphanumeric keyboard is annoying. For all the TextFields, I set the keyboard type to decimal pad.

I’m ready to try another test. Let’s take distance in miles and a speed in miles per hour and calculate time. I’ll convert distance and speed to Doubles, then set them to the runstats model. I’ll try this code.

@IBAction func calculate(_ sender: UIButton) {

    let distance = double(textField: variable1)

    let speed = double(textField: variable2)

    runStats.distance.distance(miles: distance)

    let pace = PaceStat(milesPerHour: speed)

    runStats.time(changedBy: pace)

    result.text = runStats.time.hoursMinutesSeconds()


I try a simple case where I run five miles at five miles an hour, And yes, I get the expected one hour.

I try a function with a time variable using the three textfields on the bottom. I’ll compute the pace in minutes per mile for a given distance.

@IBAction func calculate(_ sender: UIButton) {

    runStats.distance = DistanceStat(miles: double(textField: variable1))

    let seconds = Int(double(textField: self.seconds))

    let minutes = Int(double(textField: self.minutes))

    let hours = Int(double(textField: self.hours))

    let time = TimeStat(hours: hours, minutes: minutes, seconds: seconds)

    runStats.pace(changedBy: time)

    result.text = runStats.pace.minutesSecondsPerMile()


I build and run this. A simple test is a one hour run of five miles, which should give us a twelve minute mile.

And my target time for my first marathon of five hours 45 minutes ( yeah, I’m a bit slow)

As expected, I get the 13:10 pace. I’d do a lot of tests like this to make sure the components work with the model.

A Model Change

During the testing, I get the feel for using the code in the model. There’s one thing I don’t like. Consider these two statements

runStats.distance.distance(miles: 5.0)


I use different identifiers for the setter and getter. I like this better:



It is easer to read and shorter to type. It is not a huge change in the model code, and it works better. I can change the setters to this:

//set distance from miles

  public func meters(_ meters:Double){

    distanceStat = meters


  public func miles(_ miles:Double){

    distanceStat = miles * 1609.344


  public func kilometers(_ kilometers:Double){

    distanceStat = kilometers * 1000.0


I change the resulting code using these functions in the rest of the model. I’ll do the same for the other stat types. The current code only requires changes to the stat types DistanceStat, PaceStat and TimeStat. Pace and time add one wrinkle in two and three parameter setters. The first parameter becomes the name of the setter, and the rest are parameters like this:

public func hours(_ hours:Int,minutes:Int,seconds:Int) {

    timeStat = Double(seconds + minutes * 60 + hours * 3600)


I didn’t do it intially, but some uses of these functions in initializers will need to specify self to work properly.

public init(minutes:Int,seconds:Int){

    self.hours(0, minutes: minutes, seconds: seconds)


Running the code as written I get the same results, and no problems.

The 44 Warnings 

There’s one last thing to address: those 44 warnings. Closing the folders they are in, I find they fall into the following categories:

Those warnings are why Apple wants me to change this code, and threw me out of the app store to do it. This is all old stuff that needs updating. Sometimes living in the Swift world, I forget the Objective-C is improving over time too. The deprecations for example are all the same issue: there’s no more UIActionSheets in iOS.  Many of the others are number conversions which changed in newer versions of iOS in Objective-C

I have choices here: I can fix this code and remove the errors, I can ignore the errors for now, or I can delete the code now. While the errors are annoying, they are not affecting the code. I go for the last one. I will delete all of the Objective-C code before shipping, replacing it with the new Swift code. It doesn’t need to be there, but I use it as documentation for the old version until I don’t need it anymore.

So I got the new model into the old code. I started replacing components, and got the old code to actually function in the latest Xcode. My next steps are to get the views and controllers working properly. I”ll start that process not at the root, but by replacing those text views with UIPickers in the next installment.

I’m a LinkedIn Learning author, with five courses up in the LinkedInLearning library.  My latest is a trilogy for iOS notifications: Learning iOS NotificationsiOS App Development: Notifications, and watchOS App Development: Notifications If you a re interested in Notifications, I’d Check them out. 

Where is Update Frames in Xcode 8.1?

A tech author’s work is never done. As soon as he or she completes manuscript and gets it published, the manuscript almost immediately becomes obsolete. In my case, Practical Autolayout for Xcode 8 went obsolete  a day before I published, but I had no idea about a major change in Xcode 8.1.

Until Xcode 8.1, if you wanted to update a frame with new constraints, you had two possibilities. The first was in the pinpinMenuButton and align alignment iconmenu to update as you were setting the constraints.


The second was a selection in the resolver resolver button 2016-10-01_13-27-48

It seems everyone, including me was not ready for a change Apple made in Xcode 8.1. If you go to look for Update Frames in the resolver resolver button, it is missing:


So where did it go?

Apple moved this to an icon on the auto layout toolbar and deleted it from the menus.


If it were me, I wouldn’t have deleted it from the menus in such an abrupt way. Apple did. This Update Frame button  has some different behaviors  from its predecessor on the menu, and I’d like to explain that using some examples from Chapter 3 of Practical Autolayout for Xcode 8

Set up a storyboard that looks something like this with a label Hello Pizza, a text view, and  three  buttons, Pepperoni, Cheese, and Done:


Select the Hello Pizza label.  Click the pin buttonpinMenuButton in the auto layout toolbar. In the popup, set the top to 0 points, the left to 0 points and the left to 0 points.  Leave Update Frames as None


Add the 3 constraints. The Hello Pizza Label will show misplacement constraints.


Press the Update Frames button update frames  and the frame updates.


This is not always the result. You must have all constraints satisfied before the button will update frames. For example, select the text view. Press the align button alignment iconand center the text view by checking on Horizontally in Container and Vertically in Container.


Again don’t update frames, but click  Add 2 constraints. You’ll see an ambiguous constraint in red.


If you click the update frames button nothing happens. Until a frame has no ambiguity(i.e. no red constraint errors), you cannot update it. Most often that is setting a size. For the text box, set an absolute size in the pin menu pinMenuButton  of 175 points in both directions.


Add the constraints. The errors all turn to misplacements.


Once all misplacements, you can update the frame with update frames.


Priorities are not assumed with the new update frames button. When there is an ambiguity in size between two frames that depend on each other for size, you must specify the a priority for them or set a size.  Take for example these two buttons.


Pepperoni is pinned to the left margin, the label above it and the text view below it. Cheese is pinned 10 points from Pepperoni, aligned to the top of Pepperoni, and pinned 10 points from the right margin. We’d like to have two buttons that fill the available space.

The option used in Practical Auto Layout for these buttons is to make them the same size. Control drag from Pepperoni to Cheese. A menu appears.


Shift select Equal Width and Equal Heights, then hit the Add Constraints selection. The ambiguity changes to misplacements.


Select both the Pepperoni and Cheese buttons. Hit the Update Frame button update frames and two equally sized buttons appear


The other, more advanced option is to change priority of one of the buttons so they are not equal. Both are by default 250.  Going back to the original ambiguous layout,


changing the content hugging priority of Pepperoni from 250 to 251 tells auto layout for Pepperoni to keep its size and Cheese to stretch to make up the difference.


Priorities are covered in detail in Chapter 12 of Practical Autolayout for Xcode 8.

I’ll be updating the book shortly. Until then or if you cannot update your book,  consider this an errata to the versions now available.

practical-autolayout-x8-newsletterPurchase the book for  Kindle and iTunes  here: