DevFright

Learn How to Create iOS Apps

How to Setup Apple HealtKit in Your App

by Leave a Comment

Since the launch of the Apple Health app and HealthKit framework in September 2014, iPhone and Apple Watch users have had a simple way of storing all of their health related data. In Apple’s words “HealthKit provides a central repository for health and fitness data on iPhone and Apple Watch”.

Although the Health app has a simple UI and can provide health and fitness data to the user, the real power is made available when app developers interface with the HealthKit framework and build apps that specialise in certain areas.

Todays tutorial will focus on adding HealthKit to your app and preparing your app to be able to write and query data from Apple Health. This is part of a series of HealthKit tutorials that we will make with the next tutorial focusing on querying data. In future posts we will look at the HKSampleQuery, HKStatisticsCollectionQuery, to name a couple. [Read more…]

How to Use the UserNotifications Framework Delegate Protocol

by 2 Comments

In a previous tutorial, we looked at how to send a local notification. Using the basic code provided by Apple you can trigger notifications to fire almost immediately as well as at a specified date and time in the future. In this tutorial we’ll expand on this by looking at the associated delegate protocol; UNUserNotificationCenterDelegate; which allows us to detect which notification was swiped, and also detect when a notification is triggered when the app is in the foreground. To begin, download the project from here which we created in the last tutorial.

[Read more…]

How to Use the UserNotifications Framework

by Leave a Comment

Updated to work with Xcode 13 and Swift 5.

The UserNotifications framework was introduced with iOS 10 and has been designed to work with iOS, tvOS, and watchOS, and replaces UILocalNotification from the UIKit framework. UILocalNotification and other variants were deprecated in iOS 10.

If you want to send a notification to the lock screen of an iPhone, using the UserNotifications framework is now the way to go.

In this tutorial we’ll look at how to get a basic notification on to the lock screen. In the next tutorial, we’ll look at all the other parts that we do not cover here such as being able to put a notification on screen based on location; without using the CoreLocation framework, and we’ll also look at how to handle specific notifications so that we know which one was tapped or swiped.

[Read more…]

UIAlertController Tutorial

by 4 Comments

When needing to put an alert on the view of your app the previous way to handle this was with a UIAlertView or UIActionSheet. Both of these were deprecated in iOS 8 which means if you are targeting newer versions of iOS, which you should be in many cases, you now need to use UIAlertController. If you want to see how alerts worked in iOS 8 or below, you can find an example in the Location Authorization tutorial we made a few years ago.

The UIAlertController

UIAlertController became available in the iOS 8.0 SDK. Rather than go through the differences between this class and the previously used classes we’ll just look at what can be done with the UIAlertController. [Read more…]

How to Let Users Change the App Icon with setAlternateIconName – Tutorial

by Leave a Comment

When iOS 10.3 was launched it provided developers with the ability to let users change the icon in the app. In this fairly short tutorial I’ll show you how it’s done.

To begin, create a new project in Xcode. An iOS/Single View is a good place to start. Make sure you select Swift as the language. The same function can also be created with Objective-C, but this tutorial focuses on the Swift way.

setAlternateIconName Tutorial

We now need add some keys to Info.plist for the app. In particular, add the following: [Read more…]

HealthKit Tutorial – How to Fetch Weight Data with Swift

by Leave a Comment

In the last tutorial here I showed you how to create a line graph with PaintCode. In this tutorial we’ll use that line graph to plot some data. To do this we’ll get body mass (weight) data from HealthKit and plot it on the graph. By the end of this tutorial, you’ll see that although it was great to fetch the data from HealthKit and plot it on a graph, the app isn’t really that useful. In part 3, we will add more features that allow you to write data to HealthKit.

You can begin by downloading the basic tutorial where we left off last time found here.

Allowing the Points and Colours to Be Changed

As the current tutorial stands you can only display a static graph which is really of no use. Lets begin adding in the modifications that allow us to adjust the points and colours as needed.

To allow changes to be made we need to make a few modifications to the LineView class. We need to create some public variables. Open up LineView.swift and add the following just below the class definition:

// Set the UIColors here. Defaults are .red and .gray
public var lineColour: UIColor = .red
public var pointColour: UIColor = .red
public var horizontalLineColour: UIColor = .gray

// The value of the top line on the graph (defaulted to 10)
public var height: CGFloat = 10.0

// Points on the graph
public var point0: CGFloat = 8.0
public var point1: CGFloat = 1.0
public var point2: CGFloat = 2.0
public var point3: CGFloat = 3.0
public var point4: CGFloat = 4.0
public var point5: CGFloat = 5.0
public var point6: CGFloat = 6.0

// Line width is defaulted to 2.0
public var lineWidth: CGFloat = 2.0
[Read more…]

How to use the Google Maps iOS SDK with a Storyboard

by Leave a Comment

The default map view for iOS, since 2012, is Apple Maps. However, you are still able to use Google Maps in your project thanks to the Google Maps SDK. Both solutions are robust, and in many cases Apple Maps might be sufficient for your needs, but for those who need or prefer using Google Maps, read on.

This tutorial will focus on integrating the Google Maps SDK in to your iOS project. I will also show you how to add Google Maps in a storyboard.

To keep the tutorial simple, we will create a project that opens a view that displays a Google Map. It will show your current location, allow you to pan and rotate as well as zoom in and out. [Read more…]

How to Create a Line Graph with PaintCode

by 1 Comment

I have been a user of PaintCode since June 2012 when I downloaded version 1.1.1. PixelCut recently launched a new version, version 3, that brings Swift 3 compatibility to the mix amongst a few other features. The current version is priced at £99 which seems reasonable for the amount of time saved when creating resolution independent images for your app. Lets take a look and see what you can do with PaintCode.

The idea behind PaintCode is that you draw shapes in vector form, and then provide optional adjustments by using a simple expression language to add movement or changes to those shapes. Throw in some variables for colours, size, position etc… and then import that in to your app by way of a StyleKit and you have a real simple way of creating clean looking icons, charts, and other items to be used in your app. When the StyleKit is added to your Xcode project you can make calls to the class and use UIDraw to put your drawings on screen. The benefit is that you get resolution independent images that can look crystal clear at any size. This prevents the need to export @1x, @2x, or @3x and then regenerate if an @4x appears. Likewise, cutting down on the assets and putting them in code can be a great benefit for controlling the size of the app.

This tutorial demonstrates how you can make a line graph with PaintCode for your iOS app. This tutorial will form part of another tutorial which will demonstrate in more detail how to make the line graph usable within an app. [Read more…]

MKMapView and MKMapViewDelegate Introduction in Swift

by 6 Comments

If you need to show a map to your users in iOS, one way to accomplish this is to use the MKMapView class. Mix this with the MKMapViewDelegate and you have the ability to detect movement on the map, detect the state of the map such as failure loading it as well as several other items you can monitor.

In this tutorial we’ll add a map to the view, allow the current location of the phone to be zoomed to, and allow the user to switch between the different map types which are available meaning Standard, Satellite, and Hybrid. We will also learn how to implement a delegate method and have the map move each time the user moves.

MKMapView Tutorial

The first step is to create a Single View Application by opening Xcode and creating the new project. You can follow this tutorial if you are unsure how to create a new project. Make sure you select the language as Swift. You can uncheck unit tests, core data, and other optional extras.

Navigate to Main.storyboard and drag out a UIToolBar and seat it at the bottom of the view. Click the UIBarButtonItem (named Item) and rename the text attribute to “Current Location”. Drag out a Segment control and put that on the toolbar also. You might choose to use a flexible spacer between the button on the left and the segment to force them to the left and right edges of the toolbar. [Read more…]