Using Objective C framework in capacitor plugin

Capacitor
1

I have to use Objective C framework in my capacitor plugin. I added the framework in the podspec file also added the bridging header right where the plugin swift files are (ios/Sources/Plugin/…). And I wrote the code to use objective c framework in the swift file. However, it isn’t working. I managed to use swift framework but not objective c framework there.

2

Can you share any code that you’ve written so far? It’s impossible for us to know what could be happening from just reading your description

3

Using Objective C Framework in Capacitor plugin in Swift

  1. Created the plugin
  2. Added the objective C framework in Project/ios/Sources/Frameworks/
  3. Defined bridging header and module map
  4. Added the framework path, framework header path, and modulemap path in the swift packagemanager - the Package.swift file -

Package.swift


import PackageDescription

let package = Package(
    name: "UnityLoader",
    platforms: [.iOS(.v13)],
    products: [
        .library(
            name: "UnityLoader",
            targets: ["UnityLoaderPlugin"])
    ],
    dependencies: [
        .package(url: "https://github.com/ionic-team/capacitor-swift-pm.git", branch: "main")
    ],
    targets: [
        .binaryTarget(
            name: "UnityFramework",
            path: "ios/Sources/Frameworks/UnityFramework.framework"
        ),
        .target(
            name: "UnityLoaderPlugin",
            dependencies: [
                .product(name: "Capacitor", package: "capacitor-swift-pm"),
                .product(name: "Cordova", package: "capacitor-swift-pm"),
                "UnityFramework"
            ],
            path: "ios/Sources/UnityLoaderPlugin",
            publicHeadersPath: "ios/Sources/Frameworks/UnityFramework.framework/Headers",
            cSettings: [
                .headerSearchPath("ios/Sources/Frameworks/UnityFramework.framework/Headers"),
                .define("FRAMEWORK_SEARCH_PATHS", to: "ios/Sources/Frameworks/UnityFramework.framework"),
                .define("MODULEMAP_FILE", to: "ios/Sources/Frameworks/UnityFramework.framework/Modules/module.modulemap")
            ]
        ),
        .testTarget(
            name: "UnityLoaderTests",
            dependencies: ["UnityLoaderPlugin"],
            path: "ios/Tests/UnityLoaderPluginTests")
    ]
)
  1. in the swift code used used this code to load the framework

UnityLoader.swift file

  @objc public func echo(_ value: String) -> String {

      print(value)
      var ufw: UnityFramework?
      if ufw == nil {
      let unityPath = Bundle.main.bundlePath + "/Frameworks/UnityFramework.framework"
      let bundle = Bundle(path: unityPath)
      bundle!.load()
      ufw = bundle!.principalClass?.getInstance()
      ufw?.setDataBundleId("com.unity3d.framework")
      ufw?.runEmbedded(withArgc: CommandLine.argc, argv: CommandLine.unsafeArgv, appLaunchOpts: nil)
      ufw?.showUnityWindow()     
      return value
}
  1. built the plugin

However, it doesn’t work it says cannot find unityframework headers or it says that could not build objective c framework. I even tried the same thing with Bridging Headers - basically made a bridging header file and added its path in the Package.swift but that didn’t work either.

Objective C framework in Capacitor plugin using Objective C

I have tried this with objective C as well but this doesn’t work either - it says cannot find an exported struct although it is there in the UnityFramework.h file

UnityFramework.h

typedef struct mach_header_64 MachHeader;

extern const struct mach_header_64 _mh_execute_header;

Things I did:

1.	 I created a new plugin project
2.	 Deleted the swift files and added objective c files with their header files
3.	Added the objective c framework in the  project director
6.	Added the reference to the objective c framework in the podspec file
7. In the source file for the plugin, I added the code to import stuff from UnityFramework and using 
  to load the unity instance.

UnityLoader.podspec

require 'json'

package = JSON.parse(File.read(File.join(__dir__, 'package.json')))
Pod::Spec.new do |s|
  s.name = ‘UnityLoader’
  s.version = package['version']
  s.summary = package['description']
  s.license = package['license']
  s.homepage = 'https://capacitorjs.com'
  s.author = package['author']
  s.source = { :git => 'https://github.com/ionic-team/capacitor-plugins.git', :tag => package['name'] + '@' + package['version'] }
`  s.source_files = 'ios/Plugin/**/*.{swift,h,m,c,cc,mm,cpp}', ‘./**/*.{swift,h,m,c,cc,mm,cpp}'`
  s.ios.deployment_target  = '13.0'
  s.dependency 'Capacitor'
  s.swift_version = '5.1'


  s.public_header_files = 'UnityFramework.framework/Headers/*.h'
  s.dependency 'UnityFramework'
  s.xcconfig = { 
    'FRAMEWORK_SEARCH_PATHS' => '"$(PODS_ROOT)/"'
  }
  s.vendored_frameworks = 'UnityFramework.framework'

end

UnityLoader.m

	

		#include <UnityFramework/Unityframework.h>
		UnityFramework* UnityFrameworkLoad(void) {
		    NSString* bundlePath = NULL;
		    bundlePath = [[NSBundle mainBundle] bundlePath];
		    bundlePath = [bundlePath stringByAppendingString:@"/Frameworks/UnityFramework.framework"];
		    
		    NSBundle* bundle = [NSBundle bundleWithPath:bundlePath];
		    if (![bundle isLoaded]) [bundle load];
		    
		    UnityFramework* ufw = [bundle.principalClass getInstance];
		    if (![ufw appController]) {
		        // Unity is not initialized
		[ufw setExecuteHeader:&_mh_execute_header];
		    }
		    return ufw;
		}

Then built the framework and imported it in ionic app but still it didn’t work.

I have also tried putting the framework in podspec and swift package manager both in both cases and it doesn’t work either. It says linking error coudn’t find basically that _mh_execute_header doesn’t exist here linking problem and stuff like that.