How can I import Swift code to Objective-C?

Question

I have written a library in Swift and I wasn't able to import it to my current project, written in Objective-C.

Are there any ways to import it?

#import "SCLAlertView.swift" - 'SCLAlertView.swift' file not found

Solution 1

You need to import ProductName-Swift.h. Note that it's the product name - the other answers make the mistake of using the class name.

This single file is an autogenerated header that defines Objective-C interfaces for all Swift classes in your project that are either annotated with @objc or inherit from NSObject.

Considerations:

• If your product name contains spaces, replace them with underscores (e.g. My Project becomes My_Project-Swift.h)

• If your target is a framework, you need to import <ProductName/ProductName-Swift.h>

• Make sure your Swift file is member of the target

Solution 2

Here's what to do:

1. Create a new Project in Objective-C

2. Create a new .swift file  

   • A popup window will appear and ask "Would You like to configure an Objective-C bridging Header".
   • Choose Yes.

3. Click on your Xcode Project file

4. Click on Build Settings

5. Find the Search bar and search for Defines Module.

6. Change value to Yes.

7. Search Product Module Name.

8. Change the value to the name of your project.

9. In App delegate, add the following : #import "YourProjectName-Swift.h"

---

Note: Whenever you want to use your Swift file you must be import following line :

#import "YourProjectName-Swift.h"

Solution 3

Instructions from the Apple website:

To import Swift code into Objective-C from the same framework

Under Build Settings, in Packaging, make sure the Defines Module setting for that framework target is set to Yes. Import the Swift code from that framework target into any Objective-C .m file within that framework target using this syntax and substituting the appropriate names:

#import "ProductName-Swift.h"

Revision:

You can only import "ProductName-Swift.h" in .m files.

The Swift files in your target will be visible in Objective-C .m files containing this import statement.

To avoid cyclical references, don’t import Swift into an Objective-C header file. Instead, you can forward declare a Swift class to use it in an Objective-C header. Note that you cannot subclass a Swift class in Objective-C.

Solution 4

If you're using Cocoapods and trying to use a Swift pod in an ObjC project you can simply do the following:

@import <FrameworkName>;

Solution 5

Go to build settings in your project file and search for "Objective-C Generated Interface Header Name. The value of that property is the name that you should include.

If your "Product Module Name" property (the one that the above property depends on by default) varies depending on whether you compile for test/debug/release/etc (like it does in my case), then make this property independent of that variation by setting a custom name.

View more solutions

Comments

[SleepsOnNewspapers]

love this project!

[Vin]

Answer to this question can be found in the Apple documentation itself: developer.apple.com/documentation/swift/… I recommend to read the documentation first before reading all the answers.

[Dark Matter]

Showed me this error: 'SCLAlertView-Swift.h' file not found.

[Bill]

Needs to be the project name, not the filename - see my answer.

[louielouie]

Thanks for the documentation link. That was useful for reference.

[louielouie]

Note that if you try to use the Swift filename in your import, you will get the error "Expected ';' after top level declarator". in your Swift file after "import Foundation".

[Ruben Martinez Jr.]

Wow, great catch! Small question: Is there anywhere I can see what that project name is? I tried what you suggested and am still getting errors so I'm worried I might have the project name wrong.

[Ruben Martinez Jr.]

EDIT: Note: for this to work, a project module name MUST be defined. See: stackoverflow.com/a/24064015/2085743

[Hola Soy Edu Feliz Navidad]

I just would like to add a note that if your project name has any white space or special character you have to replace them with underscores, like "My App" would be "My_App-Swift.h"

[Chris]

To quote from the provided link: The name of this header is your product module name followed by adding "-Swift.h". So it's not the class name as you wrote, but the name of your product module and that takes care of importing all swift files, not just a specific one

[Alphonse R. Dsouza]

Only import "ProductName-Swift.h" in .m files helped me. Adding same in .pch file was giving "Cannot find protocol declaration for 'CLLocationManagerDelegate'; did you mean 'NSLayoutManagerDelegate'?"

[Hardik Amal]

Hi @Bill how do i use swift library through cocoapod in my objective c project...?

[marchinram]

How does this work in a Framework target, can you just add #import <ProjectName/ProjectName-Swift.h> to the umbrella header?

[uchuugaka]

Why is this so hard and poorly documented?

[Raptor]

@HardikAmal you can still use, for example, #import "SCLAlertView-Swift.h" in Objective-C class, or @import <SCLAlertView>;

[Zack Braksa]

Changing the value of Defines module in Build settings to Yes is what fixed things for me!

[Alejandro Iván]

@AJit it doesn't directly, the documentation says that. The easiest way is to create an Objective-C class that translates in a format that Objective-C++ understands. developer.apple.com/library/ios/documentation/Swift/Conceptu‌​al/…

[Mohit]

Embedded Content Contains Swift : YES USE this also

[Amit Saxena]

@uchuugaka it's not that much hard. First time you can feel a bit pain and then later you would be getting mastery on it.

[Sam B]

good answer but steps 7-8 are not needed in Xcode 7.3.1 and higher

[Maria]

Thanks! That really helps!

[itscoderslife]

Worked for me! Thanks.

[David T.]

Note that you have to derive from NSObject !!! you can't just straight up declare a class Blah in swift and have it work. it needs to be class Blah : NSObject

[inigo333]

Worth reading this answer for some cases: stackoverflow.com/questions/26328034/… Depending on what you are doing: #import <ProductName/ProductModuleName-Swift.h> #import <ProductModuleName-Swift.h> #import <NewTestApp/NewTestApp-Swift.h>

[Aamir]

I have used #import "SCLAlertView-Swift.h" in .m and I getting error: SCLAlertView-Swift.h not found, I did something wrong?

[Aamir]

@Bill now I have used #import "Wow_Dictionary-Swift.h", where Wow Dictionary is my project name. Now I am getting error Wow_Dictionary-Swift.h not found. Still something wrong?

[Bill]

@Aamir Actually, it's the target name, not the project name. Let me update my answer.

[Aamir]

@Bill my project name is same as target name.

[Philipp Otto]

The forward declaration (@class) of the class is a very good point! Thanks!

[Jaydeep Vyas]

I have skipped step NO. 6 even it is working for me... is this step really needed.??? my define module is set to NO

[fnc12]

I did this but I get 10 compile errors saying that No type or protocol UIApplicationDelegate and similar

[Ricardo]

What if you want import a Swift extension?

[jose920405]

In my case "ProductName-Swift.h" works perfect in xcode 7.3 but now works in xcode 8.3.2

[jose920405]

Not works for me in xcode 8.3.2. Works in previous versions

[rd_]

i am not getting this option of use legacy swift language version

[Roi Mulia]

Better than the approved. The dashes wasted 20 min I'll never get back haha.

[Esha]

Thanks a lot! you saved my day.

[John Franke]

Do you have to import it in your .m file?

[Bill]

@JohnOttenlips yes

[Darshan Mothreja]

@AlejandroIván I have UIView swift class will it work ? I am not able to import swift into objective c

[Sumit singh]

@jose920405 let me know what step you are following because the same steps for same Xcode version is working for me.

[lelelo]

This auto-generated file is now called TargetName-Bridging-Header.h though?

[Bill]

@lelelo No, that file is the opposite of this one. The bridging header is written by the developer and lets you bring Objective-C and C symbols into your Swift code. The Target-Swift.h file is automatically generated and lets your Objective-C/C code access Swift symbols.

[Martin-Gilles Lavoie]

The missing module was my issue for a test project. Furthermore, if your project name starts with a numerical, (eg, 1234.xcodeproj), it too will replace the first offending character with _, thus your module name will default to "_234" and thus your include will look like "_234-Swift.h".

[atulkhatri]

It's not necessarily the Target Name. It is actually Product Module Name which you have defined in Build Settings. You can have a look at the answer by Sumit Singh

[Adeel Miraj]

@Bill sorry to bother you but I have been trying to import the Swift header file but couldn't succeed. The issue is that I have 2 targets in my project. One of the Objective-C files requires to access the Swift header files of both the targets. How would I go about that?

[Bill]

Hi @Adeel You can create a new header file that #import's Target1-Swift.h and Target2-Swift.h and import that header into your Objective-C files.

[Adeel Miraj]

In the newly created header file it doesn't let me include either of the two. Moreover, if I exclude the objective-c file from one of the targets then the compiler stops complaining about the header file but starts complaining about one of objc class's subclass because that is included in both the targets.

[Tamás Sengel]

"Note that you cannot subclass a Swift class in Objective-C." Thank you for including this, it saved me from going crazy.

[NSPratik]

This works like a charm if we installed swift-made library through Cocoapods. Upvoted !!!

[Itachi]

I found a new way to find the correct generated header file name: go to your target -> Build Settings -> Search keywords Objective-C Generated Interface Header Name, bingo!

[Johannes]

Important note: You can change the module name for each target to make the name of the swift header the same for each target. Details here -> stackoverflow.com/a/27411394/956816

[SNarula]

In my code, after I updated it to Swift 4.2 from swift 3. It's not working

[Prashant Bhayani]

what error are you getting? I have used above code in Swift4.2 and its working fine.

[Chuck Boris]

Just want to add that YourProjectName in #import "YourProjectName-Swift.h" will be the name of project from step 8. Useful if your project name contains special characters and you are not sure how exactly you should format it.

[Mike]

will this work for structs. I dont believe that they can be derived from NSObject so I am guessing not. I am trying to do this with a constants class

[Prashant Bhayani]

Ok that’s great.

[user1046037]

The key is using the @objc attribute, wish you could make it in bold, because Apple's documentation doesn't state this properly. Or write it as steps.

[Iulian Nikolaiev]

Thanks a lot! This phrase "Make sure your Swift file is member of the target" saved my day!