How to declare inherited inbuilt protocol so that it can be imported from another framework or app?

Question

I am unable to call this swift file from a different app/framework as am getting the below error.

"Unknown class name 'WKScriptMessageHandler'"

This is the mySwift.swift which I have declared in a framework.

@objcMembers public class HSIWKJavascriptBridge : NSObject, WKScriptMessageHandler{
    public func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
        if message.name == "test", let messageBody = message.body as? String {
            print(messageBody)
        }
    }
}

swift compiler generated this code automatically while compiling.

@class WKUserContentController;
@class WKScriptMessage;

SWIFT_CLASS("_TtC5MyFwk21HSIWKJavascriptBridge")
@interface HSIWKJavascriptBridge : NSObject <WKScriptMessageHandler>
- (void)userContentController:(WKUserContentController * _Nonnull)userContentController didReceiveScriptMessage:(WKScriptMessage * _Nonnull)message;
- (nonnull instancetype)init OBJC_DESIGNATED_INITIALIZER;
@end

Now the error is WKScriptMessageHandler is not auto declared like

@class WKUserContentController;
@class WKScriptMessage;

due to which I am not able to use the framework.

score 0 · Accepted Answer · answered May 10 '19 at 08:44

I tried with your same HSIWKJavascriptBridge swift class in my Project setup. I was able to use this class in my Obj-C files without any problem.

Since WKScriptMessageHandler is a protocol, it will not be forward declared as other classes (WKUserContentController, WKScriptMessage) in swift compiler generated code.

Please make sure import WebKit is added in your Swift file.

How to declare inherited inbuilt protocol so that it can be imported from another framework or app?

1 Answers1