OrchardCMS/OrchardCore

public class MyContentTypeDriver : ContentDisplayDriver
{
        private readonly ClassDetailsAccessor _classDetailsAccessor;
        // .... other services used

        public MyContentTypeDriver(ClassDetailsAccessor classDetailsAccessor, /* other injected services */) { _classDetailsAccessor = classDetailsAccessor }

        public override async Task<IDisplayResult> DisplayAsync(ContentItem model, BuildDisplayContext context)
        {
            if (!CanHandleModel(model))
            {
                return null;
            }

            // Allows a user to preview the class details instead of only retrieving the class details when
            // we access the content from the known url route.  The content preview functionality uses a
            // different route.
            if (_classDetailsAccessor.ClassDetails is null)
            {
                var classId = int.TryParse(_httpContextAccessor?.HttpContext?.Request.Query["classId"], out var id)
                    ? id
                    : 23798;
                _classDetailsAccessor.ClassDetails = await _classDetailsService.GetClassDetailsAsync(classId);
            }

            // We return a null shape since we did not render the content type
            return null;
        }

        public override bool CanHandleModel(ContentItem model)
        {
            return model.ContentType == "MyContentTypeTechnicalName";
        }
}