com.unity.uiwidgets/com.unity.uiwidgets/Runtime/Plugins/ios/uiwidgets_message_manager.mm

#include "uiwidgets_message_manager.h"

#define MAX_OBJECT_NAME_LENGTH 256
static char uiwidgetsMessageObjectName[MAX_OBJECT_NAME_LENGTH] = {0};

static char* MakeStringCopy (const char* string)
{
    if (string == NULL)
        return NULL;
    
    char* res = (char*)malloc(strlen(string) + 1);
    strcpy(res, string);
    return res;
}

void UIWidgetsMethodMessage(NSString* channel, NSString* method, NSArray *args)
{
    const char* msg = NULL;
    NSError *error;
    NSDictionary* dict = @{
                        @"channel": channel,
                        @"method": method,
                        @"args": args
                        };

    NSData* data = [NSJSONSerialization dataWithJSONObject:dict options:0 error:&error];
    NSString* text = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    msg = [text UTF8String];
    
    UnitySendMessage(uiwidgetsMessageObjectName, "OnUIWidgetsMethodMessage", msg);
}

extern "C"
{
    void UIWidgetsMessageSetObjectName(const char* name){
        strlcpy(uiwidgetsMessageObjectName, name, MAX_OBJECT_NAME_LENGTH);
    }
}