iOS development

iOS requires that any app that you build and want to run on your phone or tablet must be signed with an Apple-issued certificate and provisioning profile. This manual explains the steps involved in bundling your game for iOS. During development, running your game through the development app is often preferred since it allows you to hot reload content and code wirelessly directly to your device.

Apple’s code signing process

The security associated with iOS apps consists of several components. You can get access to the required tools by singing up to the Apple’s iOS Developer Program. When you have enrolled, go to the Apple’s Developer Member Center.

Apple Member Center

The section Certificates, Identifiers & Profiles contains all the tools that you need. From here you can create, delete and edit:

Certificates
Apple-issued cryptographic certificates that identify you as a developer. You can create development or production certificates. Developer certificates allow you to test certain features such as the in-app purchase mechanism in a sandbox test environment. Production certificates are used to sign the final app for upload to the App Store. You need a certificate to sign apps before you can put them on your device for testing.
Identifiers
Identifiers for various uses. It is possible to register wildcard identifiers (i.e. some.prefix.*) which can be used with several apps. App IDs can contain Application Service information, like if the app enables Passbook integration, the Game Center, etc. Such App IDs cannot be wildcard identifiers. For Application Services to function, your application’s bundle identifier must match the App ID identifier.
Devices
Each development device needs to be registered with their UDID (Unique Device IDentifier, see below).
Provisioning Profiles
Provisioning profiles associate certificates with App IDs and a list of devices. They tell which app by what developer is allowed to be on what devices.

When signing your games and apps in Defold, you need a valid certificate and a valid provisioning profile.

Some of the things you can do on the Member Center homepage you can also perform from inside the Xcode development environment—if you have that installed.

Device identifier (UDID)
The UDID for an iOS device can be found by connecting the device to a computer via wifi or cable. Open Xcode and select Window ▸ Devices and Simulators. The serial number and identifier are displayed when you select your device.

xcode devices

If you don’t have Xcode installed you can find the identifier in iTunes. Click on the devices symbol and select your device.

itunes devices

  1. On the Summary page, locate the Serial Number.
  2. Click the Serial Number once so the field changes into UDID. If you click repeatedly, several pieces of information about the device will show up. Just continue to click until UDID shows.
  3. Right-click the long UDID string and select Copy to copy the identifier to the clipboard so you can easily paste it into the UDID field when registering the device on Apple’s Developer Member Center.

Developing using a free Apple developer account

Since Xcode 7, anyone can install Xcode and do on-device development for free. You don’t have to sign up for the iOS Developer Program. Instead, Xcode will automatically issue a certificate for you as a developer (valid for 1 year) and a provisioning profile for your app (valid for one week) on your specific device.

  1. Connect your device.
  2. Install Xcode.
  3. Add a new account to Xcode and sign in with your Apple ID.
  4. Create a new project. The simplest “Single View App” works fine.
  5. Select your “Team” (auto created for you) and give the app a bundle identifier.

Make a note of the bundle identifier as you must use the same bundle identifier in your Defold project.

  1. Make sure that Xcode has created a Provisioning Profile and Signing Certificate for the app.

  2. Build and launch the app on your device. The first time, Xcode will ask you to enable Developer mode and will prepare the device with debugger support. This may take a while.
  3. When you have verified that the app works, find it on your disk. You can see the build location in the Build report in the “Report Navigator”.

  4. Locate the app, right-click it and select Show Package Contents.

  5. Copy the file “embedded.mobileprovision” to some place on your drive where you will find it.

This provision file can be used together with your code signing identity to sign apps in Defold for one week.

When the provision expires, you need to build the app again in Xcode and get a new temporary provision file as described above.

Creating an iOS application bundle

When you have the code signing identity and provisioning profile, you are ready to create a stand alone application bundle for your game from the editor. Simply select Project ▸ Bundle... ▸ iOS Application... from the menu.

Signing iOS bundle

Select your code signing identity and browse for your mobile provisioning file. Select which architectures (32 bit, 64 bit and the iOS simulator) to bundle for as well as the variant (Debug or Release). You can optionally untick the Sign application checkbox to skip the signing process and then manually sign at a later stage.

You must untick the Sign application checkbox when testing your game on the iOS simulator. You will be able to install the application but it will not boot.

Press Create Bundle and you will then be prompted to specify where on your computer the bundle will be created.

ipa iOS application bundle

You specify what icon to use for the app, the launch screen storyboard and so forth in the game.project project settings file in the iOS section.

Creating a storyboard

You create a storyboard file using Xcode. Start Xcode and create a new project. Select iOS and Single View App:

Create project

Click Next and proceed to configure your project. Enter a Product Name:

Project settings

Click Create to finish the process. Your project is now created and we can proceed to create the storyboard:

The project view

Drag and drop an image to import it to the project. Next select Assets.xcassets and drop the image to Assets.xcassets:

Add image

Open LaunchScreen.storyboard and click on the plus button (+). Type “imageview” in the dialog to find the ImageView component.

Add image view

Drag the Image View component onto the storyboard:

Add to storyboard

Select the image you previously added to Assets.xcassets from the Image dropdown:

Position the image and make any other adjustments you need, perhaps adding a Label or some other UI element. When you are done select Product -> Build. Wait for the build process to finish.

The last step is to copy the compiled LaunchScreen.storyboardc file to your Defold project. Open Finder at the following location and copy the LaunchScreen.storyboardc file to your Defold project:

/Library/Developer/Xcode/DerivedData/YOUR-PRODUCT-NAME-cbqnwzfisotwygbybxohrhambkjy/Build/Intermediates.noindex/YOUR-PRODUCT-NAME.build/Debug-iphonesimulator/YOUR-PRODUCT-NAME.build/Base.lproj/LaunchScreen.storyboardc

Forum user Sergey Lerg has put together a video tutorial showing the process.

Once you have the storyboard file you can reference it from game.project.

Creating an icon asset catalog

This is required from Defold 1.2.175.

Using an asset catalog is Apple’s preferred way to manage your application’s icons. In fact it is the only way to provide the icon used in the App Store listing. You create an asset catalog in the same way as a storyboard, using Xcode. Start Xcode and create a new project. Select iOS and Single View App:

Create project

Click Next and proceed to configure your project. Enter a Product Name:

Project settings

Click Create to finish the process. Your project is now created and we can proceed to create the asset catalog:

The project view

Drag and drop images to the empty boxes representing the different supported icon sizes:

Add icons

Do not add any icons for Notifications, Settings or Spotlight.

When you are done, set the active scheme to “Build -> Any iOS Device (arm64)” and select Product -> Build. Wait for the build process to finish.

Build project

The last step is to copy the compiled Assets.car file to your Defold project. Open Finder at the following location and copy the Assets.car file to your Defold project:

/Library/Developer/Xcode/DerivedData/YOUR-PRODUCT-NAME-cbqnwzfisotwygbybxohrhambkjy/Build/Products/Debug-iphoneos/Icons.app/Assets.car

Once you have the asset catalog file you can reference it and the icons from game.project:

Add icon and asset catalog to game.project

The App Store icon does not have to be referenced from game.project. It is automatically extracted from the Assets.car file when uploading to iTunes Connect.

Installing an iOS application bundle

The editor writes an .ipa file which is an iOS application bundle. To install the file on your device, you can use Xcode (via the “Devices and Simulators” window). Other options are to use a command line tool such as ios-deploy or iTunes.

You can use the xcrun simctl command line tool to work with the iOS simulators available via Xcode:

# show a list of available devices
xcrun simctl list

# boot an iPhone X simulator
xcrun simctl boot "iPhone X"

# install your.app to a booted simulator
xcrun simctl install booted your.app

# launch the simulator
open /Applications/Xcode.app/Contents/Developer/Applications/Simulator.app

FAQ

Q: I am unable to install my Defold game using a free Apple Developer account.

A: Make sure that you are using the same bundle identifier in your Defold project as you used in the Xcode project when you generated the mobile provisioning profile.


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