I would like to use a Swift library in my Objective-C IOS app. I have the Swift library setup as a separate project, which builds fine in XCode. I can drag the generated Swift framework from the Swift project into the "Frameworks, Libraries and embedded content" list of my Objective-C project target. It appears with an "Embed & Sign" label.
The Apple description here: https://developer.apple.com/documentation/swift/importing-swift-into-objective-c states that
You can work with types declared in Swift from within the Objective-C
code in your project by importing an Xcode-generated header file. This
file is an Objective-C header that declares the Swift interfaces in
your target, and you can think of it as an umbrella header for your
Swift code. You don’t need to do anything special to create the
generated header—just import it to use its contents in your
Objective-C code.
When I look inside the swift .framework file, I can see the header file there. But when I import it in one of my Objective-c .m files, then the compiler says that the file is not found. I have tried both the
#import "Starscream-Swift.h"
and the
#import <Starscream/Starscream-Swift.h>
syntax.
How can I convince XCode to use the header file from the Swift framework? Do I need to copy that header somewhere, maybe? And what else do I need to think about to use a Swift library from an Objective-c IOS app?
I am using XCode version 13.4.1.
By the way, the Swift library I am trying to use is Starstream.
Xcode-generated header file is required when your own project has Objective-C and Swift classes mixed. When dealing with frameworks you either include the framework's umbrella header like this:
#import "SwiftFramework/SwiftFramework.h"
Or, more preferably, you import it with #import expression:
#import SwiftFramework;
Be advised, that only part that is exposed to Objective-C runtime is accessible from this framework (i.e. public/open classes inherited from NSObject or some other Cocoa classes)
Related
In an iOS application I have a subproject (not cocoapods) in which I have included a swift file and ObjC file (that is used by the swift file). XCode automatically created a bridging file but could not build it because apparantly bridging is not allowed in a framework. The workaround that I used was to add the objective-c header to the umbrella file and it worked. Now I need to use a swift class from ObjC. I have define module to set to YES, the generated file Framework-Swift.h . But when I try to import it in objective-c i get
Could not build Objective-C module
The closest I got after some googleing was this answer:
Ah gotcha. It looks like you're building a mixed Swift & Objective-C
pod - if that's the case, Xcode will try to import
within the generated -Swift.h header.
You'll need to create the header manually and add imports for the
Objective-C classes that you want to expose to Swift.
CocoaPods generates an umbrella header automatically and imports it
within the .modulemap, but Xcode doesn't use that when generating the
-Swift.h header
But I am unsure what header needs to be created manually.
Any ideeas or pointer about using swift in an objective-c framework ? In both ways ?
I also had similar issue when using Swift pods in my Swift project containing several targets. No Objective-C code at all. I tried to clear build folder, pods cache, derived data - nothing worked.
Solution:
Open the Build Settings for a target that contains your module code. Set the "Install Objective-C Compatibility Header" to "No"
There's a great and simple article that wraps up this case:
DEFINES_MODULE=YES
To use ObjC classes in Swift, create a bridging header and specify path to it in the build settings
To use Swift classes in ObjC, #import <ModuleName/ModuleName-Swift.h> in your *.m file (use #class SwiftClass; forward declaration in *.h file, if needed)
For swift classes and their members to be visible to objc
inherit your class from NSObject
prepend it with #objcMembers
make both the class and its members public
I have a Xcode project with Obiective-c files and swift files, Now i want to create a framework with both classes, Is this possible ?
Yes, this is straightforward and the process is documented by Apple. Please read "Swift and Objective-C in the Same Project" with thought and you'll be wiser (the section "Importing Code from Within the Same Framework Target" covers importing Objective-C in Swift from the same target, and the other way). Briefly…
For framework targets you don't need to create a bridging header to make your Objective-C importable to Swift, you just need to #import those headers you want visible to Swift in the framework's umbrella header. For that to work, the header needs to be marked public.
For Swift to be importable in Objective-C in the same framework target, make sure "Defines Module" is toggled on for the target, and in the files where you need to reference the Swift types, do an import in the style #import <ProductName/ProductModuleName-Swift.h>. If I recall this right, the Swift types / methods / properties you want to access from Objective-C will need to have been declared public for it to be accessible to Objective-C code even if it's in the same target.
I have created a dynamic framework with Swift language. In this framework I am using mailcore2-ios that was build by Objective-C code. So how can I use it in swift file of my framework?
I try "public" and add a header .h file to umbrella but it still not work, have so much error for other header file as the image what I attach.
Xcode does not allow the use of bridging headers in framework targets. You should use the methods described here : http://iosdeveloperzone.com/2014/10/03/using-commoncrypto-in-swift/
Trying to understand how I can use this in my swift project.
https://github.com/Grouper/FlatUIKit
I have copied the classes folder into my project but am not sure how to use the various .h and .m files. How would I go about using these files within my storyboard to use the custom appearances?
Did some searching and wasn't really able to understand the various threads that I found.
A bit of a broad question so I'll try to provide some basics and hopefully that helps.
If you are unaware, there is a whole book written by Apple about how to use objective-c with swift. it's available on iBooks for free Using Swift with Cocoa and Objective-C (Swift 2.1) by Apple Inc
Here is the online link
You will need to create an objective-c bridging header and import your code through the header.
Your bridging header would look like this:
#import "XYZCustomCell.h"
#import "XYZCustomView.h"
#import "XYZCustomViewController.h"
If they don't have any modules then you can use them in your swift code and it should see them. According to Apple:
Use your custom Objective-C code with the same Swift syntax you use with system classes.
let myCell = XYZCustomCell()
myCell.subtitle = "A custom cell"
If you are importing an Objective-c framework then it should already contain and umbrella header file that takes care of the bridging header stuff for you. then you just import the framework name into the class that you are planning on using.
import MyCustomFramework
Link to the apple docs here
For this, you can use a bridging header, which is used to expose Objective C code to swift. To do this, make a new header file in your project. Import the header files you would like to use in the new header file like this:
#import <FlatUIKit/FlatUIKit.h>
And then, in the build settings of your project, define the Objective-C bridging header to be the header file you just created. Now in any swift files that you would like to use the library in just import the classes like this:
import FlatUIKit
Hope this helps!
Usually I am using CocoaPods (with use_frameworks!) in order to manage my frameworks, but this PDF library (FastPdfKit) does not support CocoaPods, so i added it manually in "link binary with libraries" along with its dependencies. After that I let xcode create a bridging header for me (I created a .m file, and xcode created a bridging header automatically).
I imported the header in the bridging file like this #import <FastPdfKit/FastPdfKit.h>, but I can't acces any method/class from my swift files... (Use of undeclared type 'ReaderViewController' where ReaderViewController is a subclass of UIViewController in the framework).
I've also tried importing like this #import 'FastPdfKit.h" still gives the same errors.
To import Objective-C code into Swift from the same framework, go to Build Settings > Packaging and make sure the Defines Module setting for that framework target is set to “Yes”.