Working with Xcode configuration files

In this article on creating and managing multiple app environments in Xcode, we learned, how to set up environments such as debug, staging, and release when developing an iOS app.

In this article, we'll explore an approach by using Xcode configuration files (.xcconfig) to define environment-specific values.

Let's dive in.

Architecture & Design Patterns for iOS

This book is a practical guide to essential architectural principles and design patterns for iOS development. It covers strategies for building maintainable apps with Swift and SwiftUI, including dependency injection, navigation, common patterns, and modularization.

LEARN MORE

Creating configuration files

The first step is to create a .xcconfig file for each build configuration by selecting File → New → File and using the Configuration Settings File template.

For example, we could create:

• Debug.xcconfig
• Staging.xcconfig
• Release.xcconfig

By default, each file starts empty.

Connecting configuration files to build configurations

We can activate the configuration files in the Info tab of our project:

Connecting configuration files.

Here, we can select the corresponding .xcconfig file for each configuration.

Adding values to configuration files

Now, we can define values such as feature flags or app display names. For example:

Debug.xcconfig

APP_DISPLAY_NAME = ExampleApp Debug
FEATURE_X_ENABLED = YES

Staging.xcconfig

APP_DISPLAY_NAME = ExampleApp Staging
FEATURE_X_ENABLED = YES

Release.xcconfig

APP_DISPLAY_NAME = ExampleApp
FEATURE_X_ENABLED = NO

💡 Note: Don't use quotation marks for strings, even if they contain spaces. Values like YES and NO are treated as strings. Also, Xcode may interpret // in http:// as a comment—use https:/$()/dev.api.com as a workaround.

Accessing configuration values in code

To read these values in code, we first reference them in our Info.plist:

<key>FEATURE_X_ENABLED</key>
<string>$(FEATURE_X_ENABLED)</string>

Then access them in Swift:

Bundle.main.object(forInfoDictionaryKey: "FEATURE_X_ENABLED")