Objective-C to Swift – How to Migrate Your Project?

Wondering how to migrate your project from Objective-C to Swift? 

This article will answer the most popular and exciting questions about Objective-C to Swift project migration. 

How can you convert your project from Objective-C to Swift?

I will now describe the steps to migrate your project from Objective-C to Swift.

Step #1: Induct a competent conversion team

I assume you will not change your ’user interface‘ (UI). Other assumptions are that you are not adding new features and you will continue to use your existing ’Mobile Backend as a Service‘ (MBaaS) account.

You need a team of iOS developers with Objective-C and Swift skills. The team should also have testers. Finally, you need a project manager (PM). I recommend you form an Agile team, and our guide, “How to build an Agile development team?” can help you.

Step #2: Identify the portions of the app for converting Objective-C to Swift

First, determine which part of your Objective-C code you will convert. You can leave some parts of the app with Objective-C code intact. Apple allows Objective-C and Swift codes in the same app.

Following are a few examples of codes that you don’t need to convert to a new Swift code:

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• 3^rd party libraries;
• Helper and extension objective-C classes;
• Some Objective-C runtime aspects like ’Objective-C message send;
• Any low-level code depends on the C/C++ code.

Read more about this in “Should I convert everything to Swift?”.

Step #3: Prepare your Objective-C app for code porting

You should ensure that your Objective-C has optimal compatibility with Swift. To do this, you need to first modernize your current Objective-C codebase.

Does your current code base use nullability annotations? If not, you need to modernize it first. A modern Objective-C code base will interact better with Swift. Read “Migrating your Objective-C code to Swift” for more details.

Step #4: Objective-C to Swift conversion using tools

This is a key step in your project for migrating apps from Objective-C to Swift. There are several ways to accomplish this. You can use available tools for this conversion project. Let‘s dive in!

Tool #1: iSwift

iSwift lets you convert your existing Objective-C code to Swift. It’s an intuitive tool. They offer you a ’Swift 4-in-1 Pro bundle‘, which includes the iSwift conversion tool. It also includes a ’Swift cookbook‘ to aid you in writing Swift. Finally, there‘s ’Run Swift‘ to help you with testing.

Tool #2: Swiftify

Swiftify is easy to use. Web developers can use it, moreover, they provide an interactive playground to run Swift online. Developers can generate Swift documentation and also learn Swift easily. Access their tool here. Contact them to know how much the tool will cost you.

Tool #3: ’Advanced Project Converter‘ from Swiftify

Swiftify also has an ’Advanced Project Converter, ‘which is also called “ObjectiveC2Swift”. This has several advantages, e.g., it comes with ’Swiftify for Xcode, ‘which makes the code conversion easier.

The ’Advanced Project Converter‘ has other features, e.g., you can select a group of files to convert, add new Swift files to the project folder automatically, etc.

Read “Converting your project to Swift with Swiftify‘s advanced project converter,” which can guide you through the code conversion process. Check their pricing plans here.

Alternative step #5: Migrate your Code Manually

This is an alternative to using a tool to convert your project code. You can hire highly skilled developers. They can take a custom development approach.

To do so, your project team will need to build a new codebase in Swift from scratch after studying the Objective-C code. They will need to test it thoroughly. The team should do this on a file-by-file basis. This means that they will convert one ’class’ at a time.

Developers will need to create a new Swift ’class‘ using Xcode. They then import all relevant system frameworks. Subsequently, programmers will need to fill up the Objective-C bridging header, to get the Objective-C code for that ’class‘.

Read “Convert Objective-C app to Swift with minimum effort” to find more detailed instructions.

Coders will need to make their new Swift class accessible to Objective-C. It should be usable with Objective-C. The code migration involves the Objective-C header files, then the Objective-C modules, and finally, conversion into Swift APIs.

Follow through with the implementation and troubleshooting to ensure a successful migration.

Step #6: Test the converted code

Whether you use tools for conversion or manually convert the code, you need to test the app. Xcode offers a comprehensive UI testing framework for Swift where you can use test scripts.

The ’new project wizard in ‘Xcode guides you through the test, e.g., it asks whether you will include unit tests and UI tests. You can also record the UI test. Read “Understanding UI testing using iOS, Xcode 9 and Swift” for guidance.

Planning a bigger Objective-C to Swift conversion project?

If you have a complex requirement for migrating apps, you might need professional help. The project might be too critical for your business.

Swift is a premium skill, and the lead time for hiring could be high. This may impact your project schedule. Therefore, you may need to engage a software development company.

Check our guide, “How to find the best software development company?” to prepare for such requirements.

You can also outsource professional software developers from the field-expert software developers community at DevTeam.Space to complete your app migration project successfully. Write to us your initial requirements, and one of our account managers will get back to you with more details.

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