In a n-tier application:

#1 --------
My "business rule" classes will talk to the "data" classes.
My "presentation" classes will talk to the "business rules" classes

Can "presentation" classes talk to the "data" classes without passing through the business rules classes? Is it a good idea? Is it better if "presentation" classes always talk to the "business rules" classes and let they to deal with the "data" classes?



#2 --------

I create a business class to calculate work orders. This class talk to a data class to read data. This class actually read the tables. What happend if I want to use this business class in a form (where I have my data in views and those views have not been commited - the user still is in edit mode)? My data class will read data from the tables but the user has not save his/her changes so what he/she see is not what the business class is using. How should I handle this? Should I create another instance of the data class to work with views instead of tables?