Related
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
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
Here's what to do:
Create a new Project in Objective-C
Create a new .swift file
A popup window will appear and ask "Would You like to configure an Objective-C bridging Header".
Choose Yes.
Click on your Xcode Project file
Click on Build Settings
Find the Search bar and search for Defines Module.
Change value to Yes.
Search Product Module Name.
Change the value to the name of your project.
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"
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.
If you're using Cocoapods and trying to use a Swift pod in an ObjC project you can simply do the following:
#import <FrameworkName>;
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.
Importing Swift file inside Objective-c can cause this error, if it doesn't import properly.
NOTE: You don't have to import Swift files externally, you just have to import one file which takes care of swift files.
When you Created/Copied Swift file inside Objective-C project. It would've created a bridging header automatically.
Check Objective-C Generated Interface Header Name at Targets -> Build Settings.
Based on above, I will import KJExpandable-Swift.h as it is.
Your's will be TargetName-Swift.h, Where TargetName differs based on your project name or another target your might have added and running on it.
As below my target is KJExpandable, so it's KJExpandable-Swift.h
First Step:-
Select Project Target -> Build Setting -> Search('Define') -> Define Module
update value No to Yes
"Defines Module": YES.
"Always Embed Swift Standard Libraries" : YES.
"Install Objective-C Compatibility Header" : YES.
Second Step:-
Add Swift file Class in Objective C ".h" File as below
#import <UIKit/UIKit.h>
#class TestViewController(Swift File);
#interface TestViewController(Objective C File) : UIViewController
#end
Import 'ProjectName(Your Project Name)-Swift.h' in Objective C ".m" file
//TestViewController.m
#import "TestViewController.h"
/*import ProjectName-Swift.h file to access Swift file here*/
#import "ProjectName-Swift.h"
If you have a project created in Swift 4 and then added Objective-C files, do it like this:
#objcMembers
public class MyModel: NSObject {
var someFlag = false
func doSomething() {
print("doing something")
}
}
Reference: https://useyourloaf.com/blog/objc-warnings-upgrading-to-swift-4/
There's one caveat if you're importing Swift code into your Objective-C files within the same framework. You have to do it with specifying the framework name and angle brackets:
#import <MyFramework/MyFramework-Swift.h>
MyFramework here is the "Product Module Name" build setting (PRODUCT_NAME = MyFramework).
Simply adding #import "MyFramework-Swift.h" won't work. If you check the built products directory (before such an #import is added, so you've had at least one successful build with some Swift code in the target), then you should still see the file MyFramework-Swift.h in the Headers directory.
Be careful with dashes and underscores, they can be mixed up and your Project Name and Target name won't be the same as SWIFT_MODULE_NAME.
Checkout the pre-release notes about Swift and Objective C in the same project
https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html#//apple_ref/doc/uid/TP40014216-CH10-XID_75
You should be importing
#import "SCLAlertView-Swift.h"
Search for "Objective-C Generated Interface Header Name" in the Build Settings of the target you're trying to build (let's say it's MyApp-Swift.h), and import the value of this setting (#import "MyApp-Swift.h") in the source file where you're trying to access your Swift APIs.
The default value for this field is $(SWIFT_MODULE_NAME)-Swift.h. You can see it if you double-click in the value field of the "Objective-C Generated Interface Header Name" setting.
Also, if you have dashes in your module name (let's say it's My-App), then in the $(SWIFT_MODULE_NAME) all dashes will be replaced with underscores. So then you'll have to add #import "My_App-Swift.h".
If you want to use Swift file into Objective-C class, so from Xcode 8 onwards you can follow below steps:
If you have created the project in Objective-C:
Create new Swift file
Xcode will automatically prompt for Bridge-Header file
Generate it
Import "ProjectName-Swift.h" in your Objective-C controller (import in implementation not in interface) (if your project has space in between name so use underscore "Project_Name-Swift.h")
You will be able to access your Objective-C class in Swift.
Compile it and if it will generate linker error like: compiled with newer version of Swift language (3.0) than previous files (2.0) for architecture x86_64 or armv 7
Make one more change in your
Xcode -> Project -> Target -> Build Settings -> Use Legacy Swift Language Version -> Yes
Build and Run.
#import <TargetName-Swift.h>
you will see when you enter from keyboard #import < and after automaticly Xcode will advice to you.
only some tips about syntax, about Xcode everything has been said
you cannot import 'pure" functions, only classes, even if marked "public", so:
public func f1(){
print("f1");
}
will NOT be called in ANY way.
If You write classes., add inheritance from NSObject, other will NOT be usable.
if it inherits from NSObject, as below:
class Utils : NSObject{
static func aaa()->String{
return "AAA"
}
#objc static func bbb()->String{
return "BBB"
}
#objc private static func ccc()->String{
return "CCC"
}
}
in OBJC:
aaa() NOT called: "No known class method for selector 'aaa'"
bbb() ok
ccc() NOT called: "No known class method for selector 'aaa'"
Find the .PCH file inside the project. and then add #import "YourProjectName-Swift.h" This will import the class headers. So that you don't have to import into specific file.
#ifndef __IPHONE_3_0
#warning "This project uses features only available in iPhone SDK 3.0 and later."
#endif
#ifdef __OBJC__
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
#import "YourProjectName-Swift.h"
#endif
In Swift, how does one call Objective-C code?
Apple mentioned that they could co-exist in one application, but does this mean that one could technically re-use old classes made in Objective-C whilst building new classes in Swift?
Using Objective-C Classes in Swift
If you have an existing class that you'd like to use, perform Step 2 and then skip to Step 5. (For some cases, I had to add an explicit #import <Foundation/Foundation.h to an older Objective-C File.)
Step 1: Add Objective-C Implementation -- .m
Add a .m file to your class, and name it CustomObject.m.
Step 2: Add Bridging Header
When adding your .m file, you'll likely be hit with a prompt that looks like this:
Click Yes!
If you did not see the prompt, or accidentally deleted your bridging header, add a new .h file to your project and name it <#YourProjectName#>-Bridging-Header.h.
In some situations, particularly when working with Objective-C frameworks, you don't add an Objective-C class explicitly and Xcode can't find the linker. In this case, create your .h file named as mentioned above, then make sure you link its path in your target's project settings like so:
Note:
It's best practice to link your project using the $(SRCROOT) macro so that if you move your project, or work on it with others using a remote repository, it will still work. $(SRCROOT) can be thought of as the directory that contains your .xcodeproj file. It might look like this:
$(SRCROOT)/Folder/Folder/<#YourProjectName#>-Bridging-Header.h
Step 3: Add Objective-C Header -- .h
Add another .h file and name it CustomObject.h.
Step 4: Build your Objective-C Class
In CustomObject.h
#import <Foundation/Foundation.h>
#interface CustomObject : NSObject
#property (strong, nonatomic) id someProperty;
- (void) someMethod;
#end
In CustomObject.m
#import "CustomObject.h"
#implementation CustomObject
- (void) someMethod {
NSLog(#"SomeMethod Ran");
}
#end
Step 5: Add Class to Bridging-Header
In YourProject-Bridging-Header.h:
#import "CustomObject.h"
Step 6: Use your Object
In SomeSwiftFile.swift:
var instanceOfCustomObject = CustomObject()
instanceOfCustomObject.someProperty = "Hello World"
print(instanceOfCustomObject.someProperty)
instanceOfCustomObject.someMethod()
There is no need to import explicitly; that's what the bridging header is for.
Using Swift Classes in Objective-C
Step 1: Create New Swift Class
Add a .swift file to your project, and name it MySwiftObject.swift.
In MySwiftObject.swift:
import Foundation
#objc(MySwiftObject)
class MySwiftObject : NSObject {
#objc
var someProperty: AnyObject = "Some Initializer Val" as NSString
init() {}
#objc
func someFunction(someArg: Any) -> NSString {
return "You sent me \(someArg)"
}
}
Step 2: Import Swift Files to ObjC Class
In SomeRandomClass.m:
#import "<#YourProjectName#>-Swift.h"
The file:<#YourProjectName#>-Swift.h should already be created automatically in your project, even if you can not see it.
Step 3: Use your class
MySwiftObject * myOb = [MySwiftObject new];
NSLog(#"MyOb.someProperty: %#", myOb.someProperty);
myOb.someProperty = #"Hello World";
NSLog(#"MyOb.someProperty: %#", myOb.someProperty);
NSString * retString = [myOb someFunctionWithSomeArg:#"Arg"];
NSLog(#"RetString: %#", retString);
Notes:
If Code Completion isn't behaving as you expect, try running a quick build with ⌘⇧R to help Xcode find some of the Objective-C code from a Swift context and vice versa.
If you add a .swift file to an older project and get the error dyld: Library not loaded: #rpath/libswift_stdlib_core.dylib, try completely restarting Xcode.
While it was originally possible to use pure Swift classes (Not descendents of NSObject) which are visible to Objective-C by using the #objc prefix, this is no longer possible. Now, to be visible in Objective-C, the Swift object must either be a class conforming to NSObjectProtocol (easiest way to do this is to inherit from NSObject), or to be an enum marked #objc with a raw value of some integer type like Int. You may view the edit history for an example of Swift 1.x code using #objc without these restrictions.
See Apple's guide to Using Swift with Cocoa and Objective-C. This guide covers how to use Objective-C and C code from Swift and vice versa and has recommendations for how to convert a project or mix and match Objective-C/C and Swift parts in an existing project.
The compiler automatically generates Swift syntax for calling C functions and Objective-C methods. As seen in the documentation, this Objective-C:
UITableView *myTableView = [[UITableView alloc] initWithFrame:CGRectZero style:UITableViewStyleGrouped];
turns into this Swift code:
let myTableView: UITableView = UITableView(frame: CGRectZero, style: .Grouped)
Xcode also does this translation on the fly — you can use Open Quickly while editing a Swift file and type an Objective-C class name, and it'll take you to a Swift-ified version of the class header. (You can also get this by cmd-clicking on an API symbol in a Swift file.) And all the API reference documentation in the iOS 8 and OS X v10.10 (Yosemite) developer libraries is visible in both Objective-C and Swift forms (e.g. UIView).
Here are step-by-step instructions for using Objective-C code (in this case, a framework provided by a third-party) in a Swift project:
Add any Objective-C file to your Swift project by choosing File -> New -> New File -> Objective-C File. Upon saving, Xcode will ask if you want to add a bridging header. Choose 'Yes'.
(source: derrrick.com)
In simple steps:
A prompt appears, and then click on OK... If it does not appear, then we create it manually like in the following... Create one header file from iOS source and give the name ProjectName-Bridging-Header (example: Test-Bridging-Header), and then go to build setting in the Swift compiler code -> Objective-C bridge add Objective-C bridge name ..(Test/Test-Bridging-Header.h). Yeah, that's complete.
Optionally, delete the Objective-C file you added (named "anything" in the GIF image above). You don't need it any more.
Open the bridging header file -- the filename is of the form [YourProject]-Bridging-Header.h. It includes an Xcode-provided comment. Add a line of code for the Objective-C file you want to include, such as a third-party framework. For example, to add Mixpanel to your project, you will need to add the following line of code to the bridging header file:
#import "Mixpanel.h"
Now in any Swift file you can use existing Objective-C code, in the Swift syntax (in the case of this example, and you can call Mixpanel SDK methods, etc.). You need to familiarize yourself with how Xcode translates Objective-C to Swift. Apple's guide is a quick read. Or see this answer for an incomplete summary.
Example for Mixpanel:
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
Mixpanel.sharedInstanceWithToken("your-token")
return true
}
That's it!
Note: If you remove the bridging header file from your project, be sure to go into Build Settings and remove the value for "Objective-C Bridging Header" under "Swift Compiler - Code Generation".
You can read the nice post Swift & Cocoapods. Basically, we need to create a bridging header file and put all Objective-C headers there. And then we need to reference it from our build settings. After that, we can use the Objective-C code.
let manager = AFHTTPRequestOperationManager()
manager.GET(
"http://example.com/resources.json",
parameters: nil,
success: { (operation: AFHTTPRequestOperation!,
responseObject: AnyObject!) in
println("JSON: " + responseObject.description)
},
failure: { (operation: AFHTTPRequestOperation!,
error: NSError!) in
println("Error: " + error.localizedDescription)
})
Also have a look at Apple's document Using Swift with Cocoa and Objective-C as well.
I wrote a simple Xcode 6 project that shows how to mix C++, Objective-C and Swift code:
https://github.com/romitagl/shared/tree/master/C-ObjC-Swift/Performance_Console
In particular, the example calls an Objective-C and a C++ function from the Swift.
The key is to create a shared header, Project-Bridging-Header.h, and put the Objective-C headers there.
Please download the project as a complete example.
One more thing I would like to add here:
I am very thankful for #Logan's answer. It helps a lot to create a bridge file and setups.
But after doing all these steps I'm still not getting an Objective-C class in Swift.
I used the cocoapods library and integrated it into my project. Which is pod "pop".
So if you are using Objective-C pods in Swift then there may be a chance that you can not able to get or import the classes into Swift.
The simple thing you have to do is:
Go to <YOUR-PROJECT>-Bridging-Header file and
Replace the statement #import <ObjC_Framework> to #import ObjC_Framework
For example: (Pop library)
Replace
#import <pop/POP.h>
with
#import pop;
Use clang import when #import is not working.
Quote from the documentation:
Any Objective-C framework (or C library) that’s accessible as a module
can be imported directly into Swift. This includes all of the
Objective-C system frameworks—such as Foundation, UIKit, and
SpriteKit—as well as common C libraries supplied with the system. For
example, to import Foundation, simply add this import statement to the
top of the Swift file you’re working in:
import Foundation
This import makes all of the Foundation APIs—including NSDate, NSURL,
NSMutableData, and all of their methods, properties, and
categories—directly available in Swift.
Just a note for whoever is trying to add an Objective-C library to Swift: You should add -ObjC in Build Settings -> Linking -> Other Linker Flags.
After you created a Bridging header, go to Build Setting => Search for "Objective-C Bridging Header".
Just below you will find the ""Objective-C Generated Interface Header Name" file.
Import that file in your view controller.
Example: In my case: "Dauble-Swift.h"
Mixing Objective-C and Swift
Hight level diagram:
Same Target
//Objective-C exposes API for Swift through <target_name>-Bridging-Header.h
.swift uses .h.m = Swift consumer, Objective-C producer = <target_name>-Bridging-Header.h
//Swift exposes API for Objective-C through <target_name>-Swift.h
.h.m uses .swift = Objective-C consumer, Swift producer = <target_name>-Swift.h
Swift consumer, Objective-C producer
Add a new header .h and Implementation .m files - Cocoa class file(Objective-C)
For example <MyFileName>.h and <MyFileName>.m
Configure bridging header
When you see Would you like to configure an Objective-C bridging header click - Yes
<target_name>-Bridging-Header.h will be generated automatically
Build Settings -> Objective-C Bridging Header(SWIFT_OBJC_BRIDGING_HEADER)
Add Class to Bridging-Header
In <target_name>-Bridging-Header.h add a line #import "<MyFileName>.h"
After that you can use from Swift Objective-C's MyFileName.h,MyFileName.m
P.S. If you should add an existing Objective-C file into Swift project add Bridging-Header.h beforehand and import it
Objective-C consumer, Swift producer
Add a <MyFileName>.swift and extends NSObject
Import Swift Files to ObjC Class
Add #import "<target_name>-Swift.h" into your Objective-C file
Expose public Swift code by #objc [About]
After that you are able to use from Objective-C Swift's <MyFileName>.swift
[<product_name>-Swift.h file not found]
Different Targets
[.modulemap] and [umbrella.h] are used for exposing Objective-C for Swift. And Swift.h for exposing Swift code for Objective-C
[Vocabulary]
Click on the New file menu, and chose file select language Objective. At that time it automatically generates a "Objective-C Bridging Header" file that is used to define some class name.
"Objective-C Bridging Header" under "Swift Compiler - Code Generation".
Create a .h file from NewFile -> Source -> header file
Then save the name of file Your_Target_Name-Bridging-Header.h People here gets common mistake by taking their project name but it should be the Project's Target's name if in case both are different, generally they are same.
Then in build settings search for Objective-C Bridging Header flag and put the address of your newly created bridging file, you can do it right click on the file -> show in finder -> drag the file in the text area then the address will be populated.
Using #import Your_Objective-C_file.h
In the swift file you can access the ObjC file but in swift language only.
In the Swift 4.2.1 project in Xcode 10.1 you can easily add Objective-C file. Follow the steps below to bridge Objective-C file to Swift project.
Step_01: Create new Xcode project using Swift language:
File > New > Project > objc.
Step_02: In Swift project add new Objective-C file:
File > New > File... > macOS > Objective-C File.
Step_03: If you add a new Objective-C file into Swift project at very first time, Xcode asks you:
Would you like to configure an Objective-C bridging header?
Step_04: Select the option:
Create Bridging Header.
Step_05: A corresponding file will be generated with a name:
Objc-Bridging-Header.h.
Step_06: Now, you need setup Bridge file path in bridge header. In Project Navigator click on project with name objc and then choose:
Build Settings > Objective-C Bridging Header > Objc-Bridging-Header.h.
Step_07: Drag-and-drop your Objc-Bridging-Header.h into that box to generate a file path.
Step_08: Open your Objc-Bridging-Header.h file and import the Objective-C file which you want to use in your Swift file.
#import "SpecialObjcFile.m"
Here's a content of SpecialObjcFile.m:
#import <Foundation/Foundation.h>
#interface Person: NSObject {
#public
bool busy;
}
#property
bool busy;
#end
Step_09: Now in your Swift file, you can use an Objective-C class:
override func viewDidLoad() {
super.viewDidLoad()
let myObjcContent = Person()
print(myObjcContent.busy)
}
Logans answer works fine except in latest Swift 5 it gives some compiler error. Here is the fix for people who are working on Swift 5.
Swift 5
import Foundation
class MySwiftObject : NSObject {
var someProperty: AnyObject = "Some Initializer Val" as AnyObject
override init() {}
func someFunction(someArg:AnyObject) -> String {
let returnVal = "You sent me \(someArg)"
return returnVal
}
}
Making any Swift class subclass of NSObject makes sense also I prefer for using any Swift class to be seen in Objective-C classes like:
#objc(MySwiftClass)
#objcMembers class MySwiftClass {...}
Apple has provided official guide in this doc:
how-to-call-objective-c-code-from-swift
Here is the relevant part:
To import a set of Objective-C files into Swift code within the same app target, you rely on an Objective-C bridging header file to expose those files to Swift. Xcode offers to create this header when you add a Swift file to an existing Objective-C app, or an Objective-C file to an existing Swift app.
If you accept, Xcode creates the bridging header file along with the file you were creating, and names it by using your product module name followed by "-Bridging-Header.h". Alternatively, you can create a bridging header yourself by choosing File > New > File > [operating system] > Source > Header File
Edit the bridging header to expose your Objective-C code to your Swift code:
In your Objective-C bridging header, import every Objective-C header you want to expose to Swift.
In Build Settings, in Swift Compiler - Code Generation, make sure the Objective-C Bridging Header build setting has a path to the bridging header file. The path should be relative to your project, similar to the way your Info.plist path is specified in Build Settings. In most cases, you won't need to modify this setting.
Any public Objective-C headers listed in the bridging header are visible to Swift.
Two way Approach to use objective-c objective-c
1
Create bridge-header.h file in Xcode Project
import .h file in bridge-Header file
Set path of bridge-Header in Build settings.
Clean the Project
2
Create objective-c files in project(it automatically set path in Build Settings for you )
import .h file in bridge-Header file
Now good to go
Thanks
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
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
Here's what to do:
Create a new Project in Objective-C
Create a new .swift file
A popup window will appear and ask "Would You like to configure an Objective-C bridging Header".
Choose Yes.
Click on your Xcode Project file
Click on Build Settings
Find the Search bar and search for Defines Module.
Change value to Yes.
Search Product Module Name.
Change the value to the name of your project.
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"
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.
If you're using Cocoapods and trying to use a Swift pod in an ObjC project you can simply do the following:
#import <FrameworkName>;
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.
Importing Swift file inside Objective-c can cause this error, if it doesn't import properly.
NOTE: You don't have to import Swift files externally, you just have to import one file which takes care of swift files.
When you Created/Copied Swift file inside Objective-C project. It would've created a bridging header automatically.
Check Objective-C Generated Interface Header Name at Targets -> Build Settings.
Based on above, I will import KJExpandable-Swift.h as it is.
Your's will be TargetName-Swift.h, Where TargetName differs based on your project name or another target your might have added and running on it.
As below my target is KJExpandable, so it's KJExpandable-Swift.h
First Step:-
Select Project Target -> Build Setting -> Search('Define') -> Define Module
update value No to Yes
"Defines Module": YES.
"Always Embed Swift Standard Libraries" : YES.
"Install Objective-C Compatibility Header" : YES.
Second Step:-
Add Swift file Class in Objective C ".h" File as below
#import <UIKit/UIKit.h>
#class TestViewController(Swift File);
#interface TestViewController(Objective C File) : UIViewController
#end
Import 'ProjectName(Your Project Name)-Swift.h' in Objective C ".m" file
//TestViewController.m
#import "TestViewController.h"
/*import ProjectName-Swift.h file to access Swift file here*/
#import "ProjectName-Swift.h"
If you have a project created in Swift 4 and then added Objective-C files, do it like this:
#objcMembers
public class MyModel: NSObject {
var someFlag = false
func doSomething() {
print("doing something")
}
}
Reference: https://useyourloaf.com/blog/objc-warnings-upgrading-to-swift-4/
There's one caveat if you're importing Swift code into your Objective-C files within the same framework. You have to do it with specifying the framework name and angle brackets:
#import <MyFramework/MyFramework-Swift.h>
MyFramework here is the "Product Module Name" build setting (PRODUCT_NAME = MyFramework).
Simply adding #import "MyFramework-Swift.h" won't work. If you check the built products directory (before such an #import is added, so you've had at least one successful build with some Swift code in the target), then you should still see the file MyFramework-Swift.h in the Headers directory.
Be careful with dashes and underscores, they can be mixed up and your Project Name and Target name won't be the same as SWIFT_MODULE_NAME.
Checkout the pre-release notes about Swift and Objective C in the same project
https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html#//apple_ref/doc/uid/TP40014216-CH10-XID_75
You should be importing
#import "SCLAlertView-Swift.h"
Search for "Objective-C Generated Interface Header Name" in the Build Settings of the target you're trying to build (let's say it's MyApp-Swift.h), and import the value of this setting (#import "MyApp-Swift.h") in the source file where you're trying to access your Swift APIs.
The default value for this field is $(SWIFT_MODULE_NAME)-Swift.h. You can see it if you double-click in the value field of the "Objective-C Generated Interface Header Name" setting.
Also, if you have dashes in your module name (let's say it's My-App), then in the $(SWIFT_MODULE_NAME) all dashes will be replaced with underscores. So then you'll have to add #import "My_App-Swift.h".
If you want to use Swift file into Objective-C class, so from Xcode 8 onwards you can follow below steps:
If you have created the project in Objective-C:
Create new Swift file
Xcode will automatically prompt for Bridge-Header file
Generate it
Import "ProjectName-Swift.h" in your Objective-C controller (import in implementation not in interface) (if your project has space in between name so use underscore "Project_Name-Swift.h")
You will be able to access your Objective-C class in Swift.
Compile it and if it will generate linker error like: compiled with newer version of Swift language (3.0) than previous files (2.0) for architecture x86_64 or armv 7
Make one more change in your
Xcode -> Project -> Target -> Build Settings -> Use Legacy Swift Language Version -> Yes
Build and Run.
#import <TargetName-Swift.h>
you will see when you enter from keyboard #import < and after automaticly Xcode will advice to you.
only some tips about syntax, about Xcode everything has been said
you cannot import 'pure" functions, only classes, even if marked "public", so:
public func f1(){
print("f1");
}
will NOT be called in ANY way.
If You write classes., add inheritance from NSObject, other will NOT be usable.
if it inherits from NSObject, as below:
class Utils : NSObject{
static func aaa()->String{
return "AAA"
}
#objc static func bbb()->String{
return "BBB"
}
#objc private static func ccc()->String{
return "CCC"
}
}
in OBJC:
aaa() NOT called: "No known class method for selector 'aaa'"
bbb() ok
ccc() NOT called: "No known class method for selector 'aaa'"
Find the .PCH file inside the project. and then add #import "YourProjectName-Swift.h" This will import the class headers. So that you don't have to import into specific file.
#ifndef __IPHONE_3_0
#warning "This project uses features only available in iPhone SDK 3.0 and later."
#endif
#ifdef __OBJC__
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
#import "YourProjectName-Swift.h"
#endif
I'm integrating Swift code into a large Objective-C project, but I'm running into problems when my Swift code refers to Objective-C classes. For example, suppose I have:
An Objective-C class called MyTableViewController
An Objective-C class called DeletionWorkflow
I declared a Swift class as follows:
class DeletionVC: MyTableViewController {
let deleteWorkflow: DeletionWorkflow
...
}
If I now try to use this class by importing ProjectName-Swift.h into Objective-C code, I get undefined symbol errors for both MyTableViewController and DeletionWorkflow.
I can fix the problem in that individual source file by importing DeletionWorkflow.h and MyTableViewController.h before I import ProjectName-Swift.h but this doesn't scale up to a large project where I want my Swift and Objective-C to interact often.
Is there a way to add forward class references to ProjectName-Swift.h so that these errors don't occur when I try to use Swift classes from Objective-C code in my app?
You can create another header file that forward declares or imports the necessary classes, and then imports ProjectName-Swift.h. For example, create a file named ProjectName-Swift-Fixed.h with the contents:
// ProjectName-Swift-Fixed.h
// Forward declarations for property classes
#class DeletionWorkflow;
// Imports for superclasses
#import "MyTableViewController.h";
#import "ProjectName-Swift.h"
Then, instead of #import "ProjectName-Swift.h" in your codebase, use #import "ProjectName-Swift-Fixed.h.
This is a little silly, but it sounds like your "workaround" is what Apple intended, at least for now. From the interoperability guide:
If you use your own Objective-C types in your Swift code, make sure to import the Objective-C headers for those types prior to importing the Swift generated header into the Objective-C .m file you want to access the Swift code from.
In this devforums thread, someone mentioned they already filed a bug in Radar. You probably should too.
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
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
Here's what to do:
Create a new Project in Objective-C
Create a new .swift file
A popup window will appear and ask "Would You like to configure an Objective-C bridging Header".
Choose Yes.
Click on your Xcode Project file
Click on Build Settings
Find the Search bar and search for Defines Module.
Change value to Yes.
Search Product Module Name.
Change the value to the name of your project.
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"
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.
If you're using Cocoapods and trying to use a Swift pod in an ObjC project you can simply do the following:
#import <FrameworkName>;
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.
Importing Swift file inside Objective-c can cause this error, if it doesn't import properly.
NOTE: You don't have to import Swift files externally, you just have to import one file which takes care of swift files.
When you Created/Copied Swift file inside Objective-C project. It would've created a bridging header automatically.
Check Objective-C Generated Interface Header Name at Targets -> Build Settings.
Based on above, I will import KJExpandable-Swift.h as it is.
Your's will be TargetName-Swift.h, Where TargetName differs based on your project name or another target your might have added and running on it.
As below my target is KJExpandable, so it's KJExpandable-Swift.h
First Step:-
Select Project Target -> Build Setting -> Search('Define') -> Define Module
update value No to Yes
"Defines Module": YES.
"Always Embed Swift Standard Libraries" : YES.
"Install Objective-C Compatibility Header" : YES.
Second Step:-
Add Swift file Class in Objective C ".h" File as below
#import <UIKit/UIKit.h>
#class TestViewController(Swift File);
#interface TestViewController(Objective C File) : UIViewController
#end
Import 'ProjectName(Your Project Name)-Swift.h' in Objective C ".m" file
//TestViewController.m
#import "TestViewController.h"
/*import ProjectName-Swift.h file to access Swift file here*/
#import "ProjectName-Swift.h"
If you have a project created in Swift 4 and then added Objective-C files, do it like this:
#objcMembers
public class MyModel: NSObject {
var someFlag = false
func doSomething() {
print("doing something")
}
}
Reference: https://useyourloaf.com/blog/objc-warnings-upgrading-to-swift-4/
There's one caveat if you're importing Swift code into your Objective-C files within the same framework. You have to do it with specifying the framework name and angle brackets:
#import <MyFramework/MyFramework-Swift.h>
MyFramework here is the "Product Module Name" build setting (PRODUCT_NAME = MyFramework).
Simply adding #import "MyFramework-Swift.h" won't work. If you check the built products directory (before such an #import is added, so you've had at least one successful build with some Swift code in the target), then you should still see the file MyFramework-Swift.h in the Headers directory.
Be careful with dashes and underscores, they can be mixed up and your Project Name and Target name won't be the same as SWIFT_MODULE_NAME.
Checkout the pre-release notes about Swift and Objective C in the same project
https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html#//apple_ref/doc/uid/TP40014216-CH10-XID_75
You should be importing
#import "SCLAlertView-Swift.h"
Search for "Objective-C Generated Interface Header Name" in the Build Settings of the target you're trying to build (let's say it's MyApp-Swift.h), and import the value of this setting (#import "MyApp-Swift.h") in the source file where you're trying to access your Swift APIs.
The default value for this field is $(SWIFT_MODULE_NAME)-Swift.h. You can see it if you double-click in the value field of the "Objective-C Generated Interface Header Name" setting.
Also, if you have dashes in your module name (let's say it's My-App), then in the $(SWIFT_MODULE_NAME) all dashes will be replaced with underscores. So then you'll have to add #import "My_App-Swift.h".
If you want to use Swift file into Objective-C class, so from Xcode 8 onwards you can follow below steps:
If you have created the project in Objective-C:
Create new Swift file
Xcode will automatically prompt for Bridge-Header file
Generate it
Import "ProjectName-Swift.h" in your Objective-C controller (import in implementation not in interface) (if your project has space in between name so use underscore "Project_Name-Swift.h")
You will be able to access your Objective-C class in Swift.
Compile it and if it will generate linker error like: compiled with newer version of Swift language (3.0) than previous files (2.0) for architecture x86_64 or armv 7
Make one more change in your
Xcode -> Project -> Target -> Build Settings -> Use Legacy Swift Language Version -> Yes
Build and Run.
#import <TargetName-Swift.h>
you will see when you enter from keyboard #import < and after automaticly Xcode will advice to you.
only some tips about syntax, about Xcode everything has been said
you cannot import 'pure" functions, only classes, even if marked "public", so:
public func f1(){
print("f1");
}
will NOT be called in ANY way.
If You write classes., add inheritance from NSObject, other will NOT be usable.
if it inherits from NSObject, as below:
class Utils : NSObject{
static func aaa()->String{
return "AAA"
}
#objc static func bbb()->String{
return "BBB"
}
#objc private static func ccc()->String{
return "CCC"
}
}
in OBJC:
aaa() NOT called: "No known class method for selector 'aaa'"
bbb() ok
ccc() NOT called: "No known class method for selector 'aaa'"
Find the .PCH file inside the project. and then add #import "YourProjectName-Swift.h" This will import the class headers. So that you don't have to import into specific file.
#ifndef __IPHONE_3_0
#warning "This project uses features only available in iPhone SDK 3.0 and later."
#endif
#ifdef __OBJC__
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
#import "YourProjectName-Swift.h"
#endif