How to set up Inject for a UIKit app?

Wrap your view controllers with Inject.ViewControllerHost() at the callsite, ensure InjectionIII is running, and add '-Xlinker -interposable' to Debug linker flags. Follow the README's step-by-step guide for details.

Inject or Xcode Previews for SwiftUI development?

Inject provides live reloading in running apps with real state, while Xcode Previews are for design-time mockups. Use Inject for testing integrated app logic, but Previews are simpler for isolated UI design.

Does Inject work with CocoaPods?

Yes, you can integrate Inject via CocoaPods by adding 'pod InjectHotReload' to your Podfile, as specified in the README's integration section.

Why is my Inject hot reloading not working?

Common issues include missing linker flags, InjectionIII app not running, or incorrect project selection in the app. Check the console logs for connection errors and verify build settings.

Can I use Inject in production builds safely?

Yes, Inject code is stripped in release builds, so it adds no overhead. However, ensure all setup steps like linker flags are qualified for Debug only to avoid issues.

How to add Inject to an existing SwiftUI view manually?

Import Inject, add '@ObserveInjection var inject' to your view struct, and call .enableInjection() at the end of your body definition. No need to remove it for production.

Inject — Hot Reloading for Swift Apps

What is Inject?

Inject is a hot reloading library for Swift applications that allows developers to edit running app code and see changes reflected in near real-time. It wraps the underlying InjectionIII tool to provide a seamless developer experience, eliminating the need for full recompilation and app restart cycles. This saves significant development time by reducing wait times and enabling rapid iteration.

Target Audience

Swift developers building iOS or macOS applications with UIKit, AppKit, or SwiftUI who want to accelerate their development workflow through live coding.

Value Proposition

Developers choose Inject because it requires minimal code changes, is production-safe with no-op behavior in release builds, and integrates effortlessly with existing Swift projects. Its thin wrapper design maximizes productivity without adding complexity.

Hot Reloading for Swift applications!

Use Cases

Best For

SwiftUI developers who want instant UI feedback without rebuilding
UIKit projects needing live updates to view controllers
Teams looking to reduce iOS/macOS app development cycle times
Prototyping Swift interfaces with rapid iteration
Maintaining large Swift codebases where rebuilds are time-consuming
Educational contexts for teaching Swift UI programming with immediate visual feedback

Not Ideal For

Projects using cross-platform frameworks like React Native or Flutter where Swift is not the primary language
Teams with strict build process controls that prohibit external tools or manual linker flag modifications
Applications requiring hot reloading on physical devices without a Mac or Xcode environment

Pros & Cons

Pros

SwiftUI Live Coding

Adding @ObserveInjection and .enableInjection() allows real-time UI updates without full recompilation, as demonstrated in the README's integration example.

UIKit/AppKit Support

ViewControllerHost and ViewHost wrap classes to enable hot reloading in imperative frameworks, facilitating rapid iteration on complex views without restarting the app.

Production-Safe Design

Code is inlined as a no-op and stripped by LLVM in non-debug builds, so developers don't need to remove Inject code for production releases.

Cons

Complex Initial Setup

Requires downloading the InjectionIII app, adding linker flags, and configuring build settings like EMIT_FRONTEND_COMMAND_LINES, which can be error-prone and time-consuming.

External Dependency Risks

As a thin wrapper over InjectionIII, Inject inherits its bugs and limitations, and updates to InjectionIII might break compatibility or require reconfiguration.

Automatic Script Risks

The optional build phase script modifies source code automatically, which could introduce unintended changes or conflicts in team environments, as warned in the README.

What is Inject?

Target Audience

Swift developers building iOS or macOS applications with UIKit, AppKit, or SwiftUI who want to accelerate their development workflow through live coding.

Value Proposition

Use Cases

Best For

SwiftUI developers who want instant UI feedback without rebuilding
UIKit projects needing live updates to view controllers
Teams looking to reduce iOS/macOS app development cycle times
Prototyping Swift interfaces with rapid iteration
Maintaining large Swift codebases where rebuilds are time-consuming
Educational contexts for teaching Swift UI programming with immediate visual feedback

Not Ideal For

Projects using cross-platform frameworks like React Native or Flutter where Swift is not the primary language
Teams with strict build process controls that prohibit external tools or manual linker flag modifications
Applications requiring hot reloading on physical devices without a Mac or Xcode environment

Pros & Cons

Pros

SwiftUI Live Coding

Adding @ObserveInjection and .enableInjection() allows real-time UI updates without full recompilation, as demonstrated in the README's integration example.

UIKit/AppKit Support

ViewControllerHost and ViewHost wrap classes to enable hot reloading in imperative frameworks, facilitating rapid iteration on complex views without restarting the app.

Production-Safe Design

Code is inlined as a no-op and stripped by LLVM in non-debug builds, so developers don't need to remove Inject code for production releases.

Cons

Complex Initial Setup

Requires downloading the InjectionIII app, adding linker flags, and configuring build settings like EMIT_FRONTEND_COMMAND_LINES, which can be error-prone and time-consuming.

External Dependency Risks

As a thin wrapper over InjectionIII, Inject inherits its bugs and limitations, and updates to InjectionIII might break compatibility or require reconfiguration.

Automatic Script Risks

The optional build phase script modifies source code automatically, which could introduce unintended changes or conflicts in team environments, as warned in the README.

Inject

What is Inject?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

Inject

What is Inject?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?