Expose an Objective-C class to JavaScriptCore, with automatic JavaScript constructor generation.

javascriptcore-constructor-test.m

// cc -framework JavaScriptCore -fobjc-arc -o javascriptcore-constructor-test javascriptcore-constructor-test.m

#include <JavaScriptCore/JavaScriptCore.h>

@protocol TestInterface <JSExport>

- (instancetype)initWithString:(NSString *)string;

@property (readonly) NSString *string;

@end

@interface TestClass : NSObject <TestInterface>
@end

@implementation TestClass

@synthesize string = _string;

- (instancetype)initWithString:(NSString *)string
{
    if (!(self = [super init]))
        return nil;

    _string = [string copy];

    return self;
}

@end

int main(int argc, char **argv)
{
    JSContext *context = [[JSContext alloc] init];
    context[@"TestClass"] = [TestClass class];
    JSValue *result = [context evaluateScript:@"(new TestClass(\"Hello, world!\")).string"];
    NSLog(@"Result: %@", result);
    return 0;
}

This works on iOS 7.1 and 8.0, outputing "Result: Hello, world!".