Meta-programming is a great thing. If you easily get access to the data about the class structure then you can automate a few things. In the high level language I use, I define a class like 'Property' for example. Add an integer for street number, a string for street name and a reference to the owning debtor. I then auto generate a form that has a text box for street number and street name, a lookup box for the debtor reference and the code to save and load is all auto-generated. It knows that street number is an integer so its text box can only accept integers. If I declare a read only property it will also make sure the text box is read only.