i am creating a plugin for reCaptcha version 2 (nop supports version1) and i want to overide the nopCommerce CaptchaValidator attribute, and implement in the OnActionExecuting the new version, what would be the best way to do it from a plugin?
I think it is no way. The CaptchaValidatorAttribute already inherit from ActionFilterAttribute. So i think you can inherit from ActionFilterAttribute and override OnActionExecuting to do your things. Make your captcha plugin actived first.