when I want use swift file in objective c project and I declare an object from swift class, I get "Use of undeclared identifier" error.
the way that I pass:
coping swift file in project and type #objc before declare swift class
create header file in project manually
set "Defines module" in target to Yes
set objective-C bridging header in target to $(SRCROOT)/$(PRODUCT_MODULE_NAME)-Bridging-Header.h
declare #import "productModuleName-Bridging-Header.h" in objective-c file
use name_of_swift_class *s = [[name_of_swift_class alloc] init];
when I want use swift file in step 6 I get "Use of undeclared identifier" error. why?!!! do I have the mistake?
when I test this steps in new project I don't get error but in project that I want it return error.
thank you for your help
The problem is at Step 5 You should not be importing "productModuleName-Bridging-Header.h" instead you should be importing "productModuleName-Swift.h"
P.S- After making this change clean your project, clear your derived data and build it. It will work. Hope it helps :)
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 working on an objective-c project. I added a swift framework, which gave me errors.
When I touch "command" can find the file. When I use #import also can add "ChartLineView.swift".
But when I implement it as,
ChartLineView *cl = ....
I get an error, " Use of undeclared identifier LineChartView"
What could be wrong?
I guess your are having issue in importing swift library(added via cocoapods) in your Objective C project. Just go in your .m file and import the swift library like this.
#import LineChartView; // i suppose LineChartView is the swift library name.
I have installed cocoapods in a swift project and installed TSMessage through it. No problem there, but when I try to use it with this instruction:
TSMessage.showNotificationWithTitle("Success Notification !!!", type: .Success)
I get the error :
Use of unresolved identifier 'TSMessage'
I include it like this in my bridging header:
#import <TSMessages/TSMessage.h>
Actually I finally found the answer in this article, you have to add import TSMessages at the top of the file where you want to use this class
My team has a few full Obj-C libraries we like te reuse in our projects. To do so, we usually set up a git submodule, and then add it to the xcode project as a sub-project (Using target dependency, link binary with library and updating the User Header Search Paths)
So far it's only been done in full Obj-C projects, and I'm now trying to use it in a Swift project but with very little success so far. I tried to add the briding-header file, referenced it in the project and filled it like so :
#import "MyLibraryHeader.h"
With the target header being in the User Header Search Paths.
It lets me build, but when using it in my Swift files:
let test = MyLib();
let secondTest = MyLib.classMethod1("some_arguments");
I get an EXC_BAD_INSTRUCTION on secondTest, and the following logs in the debugger:
(lldb) po test
error: <EXPR>:1:1: error: use of unresolved identifier 'test'
(lldb) po secondTest
error: Error in auto-import:
failed to get module 'MyProject' from AST context:
/Users/siegele/Sources/MyProject_iOS/MyProject/Classes/MyProject-Bridging-Header.h:12:9: error: 'MyLibraryHeader.h' file not found
#import "MyLibraryHeader.h"
^
failed to import bridging header '/Users/siegele/Sources/MyProject_iOS/MyProject/Classes/MyProject-Bridging-Header.h'
Found the following question with no answer : Xcode 6 crashing when using Objective-C subproject inside Swift
Any help would be appreciated.
I followed the HockeyApp tutorial that can be found here:
http://support.hockeyapp.net/kb/client-integration-ios-mac-os-x/integrate-hockeyapp-for-ios-as-a-subproject
In the end, I was on the right tracks but messed up the Header Search Paths:
Add subproject xcodeproj to the workspace
On the main project : Link binary with library, and add the subproject product library (Bonus points : add it as a target dependency too)
Update Header Search Paths (not User Header Search Paths) accordingly
Import your Library.h in the main project Bridging-Header.h file
What threw me off for a while is that the Swift Compiler setting for the Objective-C Bridging Header was not set automatically. Check the Build Settings for your target and ensure the "Objective-C Bridging Header" setting is not blank.