importing swift framework into a objective-c project

Question

I am importing swift framework into objective-c project like this:

@import MyFramework;

The problem is that only some of the classes are recognized by the class i am importing the framework.

The class which is recognized:

public class RecognizedClass:UIViewController, WKNavigationDelegate, WKScriptMessageHandle 
 { ... } 

The class which is not:

public class VeediUtils
{ ... } 

They are both public so why the first is recognized in the workspace and the other not?

Also i see in the header file MyFramework-Swift.h that a class

@interface RecognizedClass : UIViewController <WKNavigationDelegate, WKScriptMessageHandler>

Appear while the other dont

Why is that?

Also to point that this same procedure work when i am importing swift framework to swift project

Answer 1

If you previously configured Project for integrating with Swift and want to use Swift Dynamic Framework, you have to import it like this way (replace {value} with appropriate names depending on your Project):

#import <{MyFramework}/{MyFrameworkMainClass}-Swift.h>  
#import "{YourProjectTargetName}-Swift.h"

EDIT:

If your framework has Defines Module set to true , then you can import it like this:

@import MyFramework;

Answer 2

To access a swift class in objc, that is not inherited from NSObject you need to:

@objc public class VeediUtils

A Swift class or protocol must be marked with the @objc attribute to be accessible and usable in Objective-C. This attribute tells the compiler that this piece of Swift code can be accessed from Objective-C. If your Swift class is a descendant of an Objective-C class, the compiler automatically adds the @objc attribute for you.

https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html

Answer 3

You have to add @objc to the declaration of the VeediUtils class, or make it inherit from NSObject . Otherwise it won't be visible to Objective-C.

In your case, RecognizedClass is recognized because it is a subclass of UIViewController , which is a subclass of NSObject .

Answer 4

Using Swift Classes in Objective-C

If you are going to import code within an App Target (Mixing Objective-C and Swift in one project) you should use the next import line #import "<#YourProjectName#>-Swift.h" to expose Swift code to Objective-C code ^{[Mixing Swift and Objective-C code in a project]}

In this post I will describe how to import Swift framework to Objective-C code

Objective-C consumer -> Swift dynamic framework

Xcode version 10.2.1

Create a Swift framework

Follow Create Swift framework

Expose Swift API. To use Swift's functions from Objective-C ^[About]

Objective-C consumer

Follow Using Swift framework

Import module to the Objective-C client code ^{[module_name]}

@import module_name;

[More examples here]

Answer 5

Using Swift Classes in Objective-C

If you are going to import code within an App Target (Mixing Objective-C and Swift in one project) you should use the next import line #import "<#YourProjectName#>-Swift.h" to expose Swift code to Objective-C code ^{[Mixing Swift and Objective-C code in a project]}

In this post I will describe how to import Swift framework to Objective-C code

Objective-C consumer -> Swift dynamic framework

Xcode version 10.2.1

Create a Swift framework

Create a framework project or create a framework target

File -> New -> Project... -> Cocoa Touch Framework
//or
Project editor -> Add a Target -> Cocoa Touch Framework

Two files will be generated:

1. Info.plist - Build Settings -> Info.plist File
2. <product_name>.h - Build Phases -> Headers . It is umbrella header file ^[About]

Add files .swift

Select `.swift` file -> Select File Inspectors Tab -> Target Membership -> Select the target
//or
Project editor -> select a target -> Build Phases -> Compile Sources -> add files

Expose Swift API. To use Swift's functions from Objective-C ^[About]

Build library - ⌘ Command + B or Product -> Build

Note: Be sure that you build the framework for the same process architecture as the client code.

Find generated output ^{[Build location]}

Products group -> <product_name>.framework -> Show in Finder

The framework includes

• Info.plist
• Modules folder with:
  • module.modulemap ^{[About] [Custom modulemap]} This file was autogenerated because Build Settings -> Defines Module -> YES
  • <product_name>.swiftmodule folder with
    • .swiftdoc - docs
    • .swiftmodule - public interface/definitions
• Headers folder with:
  • files from Headers section. There are public interfaces/definitions
  • <product_name>-Swift.h - Xcode-generated header file ^[About]

Using Swift framework

Drag and drop the binary into the Xcode project ^[About]

Embed binaries ^{[Library not loaded] [Link vs Embed]}

Project editor -> select a target -> General -> Embedded Binaries -> path to `<product_name>.framework` file

I will automatically add the framework to:

1. Project editor -> select a target -> General -> Linked Frameworks and Libraries
2. Project editor -> select a target -> Build Phases -> Embed Frameworks
3. Project editor -> select a target -> Build Phases -> Link Binary With Libraries

Add Framework Search paths ^{[Module not found] [Recursive path]}

Project editor -> select a target -> Build Settings -> Search Paths -> Framework Search paths -> add path to the parent of `<product_name>.framework` file

Import module to the Objective-C client code ^{[module_name]}

@import module_name;

More examples here