DevFright

Learn How to Create iOS Apps

HealthKit Tutorial – How to Fetch Weight Data with Swift

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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

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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

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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

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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…]

iBeacons Tutorial in Swift

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When iOS 7 was announced in 2013, one of the items on the list of new API was iBeacon. The iBeacon API became part of the CoreLocation Framework by adding to the CLLocationManager class something called “Beacon Ranging”. Just like region monitoring based on location, known as GeoFencing, Apple also uses an iBeacon (or iBeacons for multiple beacons) as a region, and thus, when you come in to range of an iBeacon your iPhone can detect this and respond accordingly.

If you understand what an iBeacon is and what to do with them, you might want to jump the initial part of this post as the tutorial is further down the page. Click here to do so.

This tutorial is based on the previous iBeacon tutorial for Objective-C that I wrote in 2013. This new tutorial is based on the newer Swift programming language (version 3 at the time of writing).

What is an iBeacon?

An iBeacon is a bluetooth transmitter that emits a signal at a number of times per second (often 100ms or 10 times per second). It uses BLE (Bluetooth Low Energy) which means that a small battery, such as a coin cell, can power a device for a month or more. Using larger batteries the charge can last a year or longer.

The iBeacon is represented in iOS as a CLBeacon which has 3 properties to identify the iBeacon and another 3 to get information about the beacon. These properties are:

Identification
1. proximityUUID
2. major
3. minor

ProximityUUID is a unique identifier that you randomly generate for your business. An example of this could be a supermarket deploying 1000’s of beacons, but each of these would use the same UUID. This UUID does not need to be registered with Apple; you just randomly generate it when you create your app and then program each of your beacons with it. I will explain a little more about proximityUUID and how it relates to “region monitoring” later on in the tutorial. [Read more…]

Touch ID Tutorial – Objective-C

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The 5S was the first iPhone that integrated a fingerprint sensor in to the home button. When configuration is complete, it allows quick access to the iPhone by checking if your fingerprint matches one that is stored. If there’s a match, you get in and if not, it denies access.

When Touch ID was introduced in iOS 7 on the iPhone 5S, it was only available for Apple apps. When iOS 8 launched, they allowed 3rd party developers to also access this feature. In todays tutorial, we’ll take a look at how to integrate touch ID in to your iPhone app. Note that since the new iPad air and new iPad mini now include a touch ID sensor, this tutorial is also compatible with those devices although I will be testing with an iPhone 6.

Requirements

This tutorial requires that you have an iPhone 5S or newer or the latest iPad air or latest iPad mini (basically any iOS device with a touch ID sensor). You also need to be running iOS 8 or newer and also be using Xcode 6. Because we will be testing on an actual device rather than a simulator, you will also need to be enrolled in the iOS developer program and have paid the $99 yearly fee.

Creating the Project

First, load up Xcode 6 and go to create a new project. To save some steps setting up a default view, select the Single View Application (in the iOS section) and click Next. Give the project a name such as Touch ID and fill in the Organisation name, Organisation Identifier and set the other options as below. Note that the general way we select an organization identifier is by spelling out a name in reverse. In the case of our app development business which is mobient.co.uk, we reverse that by putting uk.co.mobient. In the Bundle Identifier line below, the Touch-ID (project name with hyphen automatically added) gets appended to the end.

New_Project [Read more…]

Please Welcome Martin to DevFright.com

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Although we have been quiet around here for the last few months, I would now like to welcome Martin to the DevFright team. Martin will be joining me in creating comprehensive iOS tutorials. In fact, he has already been posting tutorials for the last few weeks which include Localization in Xcode 6, Swift Action – UIAlertController as well as a few other tutorials about some of the less mentioned features of Xcode and iOS development. His author page which shows all his current posts can be found here.

Martin has been an iOS developer for a few years now and has experience building a number of apps as an indie developer. Those can be found at M45Apps.com for those of you who want to take a look at his quality of work.

I have been working with Martin for a few months now and we have teamed up to work on this website as well as provide app building services.

So you can get a feel of one of Martins apps, he recently launched Reflektere (Norwegian for Reflect I believe) which is available on the app store. We have 10 codes to give away for the first 10 users who comment (indicating that you want a code for a free download). Please use a valid email address to post your comment and we will pass the code to your email address so you can get a free copy of the app.

The Reflektere app uses a number of frameworks to allow it to store data, retrieve data, get location, set timers, pass notifications and eventually, we will add the iBeacon classes to it so you can get messages based on proximity to an iBeacon. All these types of technologies will be explained in detail over the coming months if we haven’t covered the subject already.

Moving on to Swift

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It’s been a while since I added tutorials to DevFright, but now that I have some work completed, it is time to get working again and creating some great and helpful tutorials for you. Due to that big announcement a bit ago at WWDC 2014, I have decided that I’ll now focus on providing Swift tutorials rather than continue the focus on Objective-C. I have thought about a mixture of both, but settled on just Swift as this is where Apple is now focussing on the coming months and years and it makes sense to switch over ready for when iOS 8 launches in a few months time.

If you have any specific tutorials you want to see, drop a note in the comments below and I’ll do my best to accommodate.

iOS Data Download Progress Bar Tutorial

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You have probably seen a number of times an app that shows the progress of a download. Today, we’ll look at one way how this is accomplished. In this tutorial I’ll show you how to create a progress bar that fills up as more data is downloaded. The data we’ll download will be an image downloaded from the internet.

iOS Progress Bar Tutorial

Lets begin by loading up Xcode and creating a Single View Application.

Call the project “Progress Bar” and leave the rest of the options as default. You can choose iPad or iPhone for this project although we’ll create it for the iPhone in this tutorial. When you get to the option on the next page asking if you want a GIT repository, you can either select or deselect it.

navigationWhen the project is ready to go, load up the storyboard by clicking on Main.storyboard in the navigation pane to the left. When the storyboard loads up, you will see just a single view that is currently empty. We need to add a few objects to it which will include a progress bar and an image view. All this simple app will do is load up a pre-defined URL and as the page loads, it will show the progress of the page load and when done, it will show the item on screen. [Read more…]

NSArray reverseObjectEnumerator Tutorial

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In the last tutorial, we looked at the sortedArrayUsingComparator method which allows you to run a comparison on objects in an array and rearrange the objects in the array. In this tutorial we will look at a simple method which can be used to reverse the order of the contents of an array. Just be aware that this tutorial is quite brief as the code is relatively simple to use… it’s just a single line if you already have an NSArray to use.

Lets say you have 5 NSStrings which are a,b,c,d,e. When we iterate through these they will come out in the order of a,b,c,d,e. What if we want to show this information in a table view, but in reverse order? i.e., e,d,c,b,a. We do this with the reverseObjectEnumerator method of NSArray. [Read more…]