I want to have a way to import my Swift Cocoapods globally in every class, how can I achieve this?
I tried a lot of things and they didn't work. Here are some ways I haven't tried and thought may be possible if found a way to work them:
Have a general import statement like UIKit and put everything in there. (Edit: This failed)
Somehow put Swift frameworks in the Obj-C briding header and import the stuff in there.
You should be able to import it globally by adding #_exported before the import.
#_exported import MyPodModuleName
However, like the other answer mentions, doing that for an entire module is not recommended, because it introduces implicit coupling between modules.
Hence instead try something like:
import Foundation
#_exported import class MyModuleName.MyClassName
#_exported import class MyModuleName.MyOtherClass
It's strongly discouraged in Swift because that would introduce implicit coupling between modules.
However, you can make a certain symbol available globally by declaring a typealias in the module that imports the other module:
import ModuleName
public typealias ClassName = ModuleName.ClassName
As of Swift4:
Being in a Swift project
Want to have another Swift project globally
imported (and using cocoapods)
I just managed to do that by adding the following line to my bridging header:
#import <PodName/PodName-Swift.h>
How good/bad this practise is? Not sure, but I just wanted some extensions globally available in my project. this did the trick.
There is no way to do this. And this is not a bug, this is a language feature (so far, as speaking of Swift 2.2).
Swift uses modules (Apple introduced them in Xcode 5 for Objective-C) and each file is an semantic unit, so you need to explicitly inform Xcode which modules are exposed to defined file.
Not only there is no support for your described behaviour, but you shouldn't also try to bypass it. Using unnecessary (unused) modules could theoretically produce slower code (taking into account that compiler uses this information to its optimisation process).
You can manually achieve the same functionality by:
Creating the Objective-C Bridging Header file;
Adding #import <UIKit/UIKit.h> to the Objective-C Bridging Header file (so that you don't need to repeat this for every single .swift file).
for pods you have to do like #import <SwiftyJSON/SwiftyJSON-umbrella.h>
A reason you wouldn't want to do this:
Imagine if both your frameworks would use the same method name, it would make things ambiguous for the compiler.The compiler won't know which method it should run.
To find out more see this question
Related
I'm building a mixed language framework. I mainly have Swift files, and a few Objective-C ones.
One of the Objective-C files is a crypto class that uses CommonCrypto.
It seems that I can't import it for some reason, even though that I can import it in a Objective-C framework.
Can someone explain to me why that is?
All the other solutions that I found talk about how to use CommonCrypto in Swift when I need to use it in Objective-C in a Swift framework.
P.S:
I tried adding the import in the umbrella header file like so:
#import <CommonCrypto/CommonCrypto.h>
the error: Include of non-modular header inside framework module 'name of header'
This answer did not fix the problem: answer
I've encountered this very problem myself. Here's how you resolve it:
Create a module map file (here's my file).
Copy the latest CommonCrypto.h header.
Create a directory CommonCrypto for both these files.
Copy the directory (via drag-and-drop) to your project.
Add the directory path under SWIFT_INCLUDE_PATHS for your target framework.
This should allow you to use import CommonCrypto wherever you want (for Swift, not Objective-C).
Edit: Seems like I misread the question initially. You want to use CommonCrypto in Objective-C and then use that from Swift. Here's some advice: don't #import CommonCrypto in your public headers, but rather just internally. Wrap all your crypto-structures so that there's no public dependency for CommonCrypto whatsoever, and then just use it from Swift via the default bridging procedure.
I have a mixed Swift and Objective-C project. To access a Swift public API in Objective-C, the API consumer currently has to import "MyModule-Swift.h". I already have a Objective-C umbrella header called "MyModule.h". But, importing "MyModule.h" is not going to work for the Swift APIs. I tried importing "MyModule-Swift.h" in the umbrella header, but it doesn't find it (I'm assuming since it is generated on the fly by Xcode).
Any suggestions so that an API consumer can always import "MyModule.h" to use public APIs written in Swift/Objective-C will be really appreciated.
====================================================================
Edit: I apologize for not taking the time to properly frame the question. I have a framework called MyModule.
I have a Objective-C class called ABUser,
#interface ABUser: NSObject
- (void)walk;
#end
I wanted to add new behavior to this class using Swift, so I defined an extension
extension ABUser {
func swiftWalk()
}
Now, say I wanted to access the swiftWalk method defined on ABUser from an Objective-C app, I would have to #import <MyModule/MyModule-Swift.h>. #import <MyModule/MyModule.h> would work if I wanted to use the walk method. This is assuming the umbrella header MyModule.h imports ABUser.h.
I always wanted the Objective-C app to #import <MyModule/MyModule.h> and never have to worry about whether an API was written in Objective-C or Swift in the framework. So, I tried importing MyModule-Swift.h in the umbrella header MyModule.h. But, my Objective-C app didn't compile if do that. Not sure, if this is because MyModule-Swift.h is generated by Xcode on the fly during the build process.
Edit 2: Added a sample project to reproduce this issue here: https://github.com/priteshshah1983/MyObjectiveCApp
The relevant code is in ViewController.m. The build will fail with the master branch. To get it work, checkout the working branch.
The reason that using #import MyModule; worked, is that "modules are a packaging together of the framework executable and it's headers" (from this SO post).
In other words, when you #import MyModule;, Objective-C automatically imports all the swift and Objective-C headers related to the module, while you cannot include the swift header from the umbrella header. I suggest you take a look at the differences between #import and #import in the linked SO answer.
It turns out that using #import MyModule; instead of #import <MyModule/Module.h> allows using walk and swiftWalk methods as expected from the Objective-C app.
I honestly don't understand the details, but I hope this helps someone else. Please feel free to explain!
I was wondering what could be used instead of pch in swift.
Is there any alternative to pch or way to get rid of import in swift so that we don't need to do this for all classes.
I don't want to carry around/import all the time. What could be the best substitute of pch in swift.
You cannot define "Macros" in swift, so there is no ".pch" file for swift.
Also, Swift doesn't have separate "Header (.h) and Implementation (.m)", so there is no need of predefined headers which are needed to compile.
For more information refer to this question, Why .pch file not available in swift?
Class Import Problem:
In Swift, you don't need to write "import" statement for your project classes everywhere. You can access the project classes just by creating their objects.
Pods:
If you are using pods then it's necessary to import frameworks in
every class where you are using.
Third Party Swift Frameworks:
For external Frameworks/Modules, you can create a bridging header file
and replace the below line with your framework/module name:
#import ModuleName;
Reference: Implicitly import specific Swift module
There is no Swift equivalent for Objective-C .pch files.
Module is alternative for it.
I have a framework (let's call it MyKit) written in Objective-C that I'm extending with some Swift classes. I'm trying to get my head around it using this documentation: https://developer.apple.com/library/ios/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html#//apple_ref/doc/uid/TP40014216-CH10-XID_77
As far as I understand, I'm not supposed to have a bridging header class, and instead put all my includes in the umbrella header file (that I understand to be ).
So I write in MyKit.h:
#import <MyKit/ModelObjectA.h>
#import <MyKit/ModelObjectB.h>
#import <MyKit/ControllerObjectC.h>
I don't list ControllerObjectD.swift, even though it goes into here as well? Or should I include
#import <MyKit/ControllerObjectD-Swift.h>
?
ControllerObjectD uses ModelObjectA and ModelObjectB. Now that I don't have a bridge headerfile, I get compile errors in it because it cannot find these objects.
The documentation says "Swift will see every header you expose publicly in your umbrella header." and this is true when I import the framework into other projects, but the framework project cannot compile because it doesn't see it. I have turned on the "Define Modules" build setting.
Is there something I've misunderstood about the umbrella header, perhaps? Where can I say "hi project, this is the umbrella header file"? The framework compiles if I set the umbrella header file as bridging header, but that sounds like I've come back to the beginning this way?
Cheers
Nik
I believe your problem may be down to the Access Modifiers in your Swift class, however I've written a short guide and sample project to help you:
Sample project can be found here
There are two parts to having a mixed language framework:
Importing Objective-C into Swift
Importing Swift into Objective-C
1. Importing Objective-C into Swift
This is, for example, if you have an Objective-C class named Player that you want to add to a swift class called Game.
According to the documentation, you need to do these two steps to import the Player object into the Game object.
Under Build Settings, in Packaging, make sure the Defines Module setting for that framework target is set to Yes.
In your umbrella header file, import every Objective-C header you want to expose to Swift.
#import <Framework/Player.h>
Make sure your Player header file in Objective-C is marked for public target membership in the framework:
Following these steps, it's possible to import the Player Objective-C class into the Game Swift Class:
import UIKit
public class Game: NSObject {
public let player: Player
public init(player: Player) {
self.player = player
super.init();
}
}
2. Importing Swift into Objective-C
For importing the Swift Game class into the Player object, we can follow a similar procedure.
As before; 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/ProductModuleName-Swift.h>
In my case, this works as:
#import <SwiftObjC/SwiftObjC-Swift.h>
and I assume, for you:
#import <MyKit/MyKit-Swift.h>
Therefore, make sure that all the properties, methods and classes you want to access are defined as public in your swift file or else they won't be visible to Objective-C .
I have uploaded my sample project showing how this all works on GitHub https://github.com/elliott-minns/SwiftObjCTestFramework
I hope this helps you with your problem.
I think you need to do bridging-header to access your obj-c code in swift.
More in the link
https://developer.apple.com/library/ios/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html
so it is a file with your imports from obj-c transfering to swift. names are very important so care about that. hope it helps
p.s. also you need to add this header path to your project settings
From the Documentation at Apple: A Swift class must be a descendant of an Objective-C class to be accessible and usable in Objective-C. For more information about what you can access from Objective-C and how the Swift interface is imported, see Swift Type Compatibility.
So your public swift class needs to extend NSObject for example.
Is there a way to import all files from a framework, and not just the specific headers you want? This may seem inefficient, but I was just curious if this was possible?
Apple's convention is to use a header within the framework which has the same name as the framework:
#import <Foundation/Foundation.h> // << imports all public headers of Foundation.framework
If the framework in question does not include such a file, you can always write your own.
Even better, you can use modules, which use the syntax: #import Foundation;. This is similar to #import <Foundation/Foundation.h>, but uses a much improved compilation model.
Note: Modules are presently supported in Xcode for Apple's frameworks, although support for user-defined module maps exists in clang. So, hopefully we can define our own modules soon.