1. A method performed on a computer processor, said method comprising: identifying a data object comprising a plurality of properties; for a first property within said plurality of properties, a calling routine issuing a first property request event comprising said first property; identifying a first value provider having a subscription for said first property request event and causing said first value provider to determine a first property value for said first property; receiving said first property value for said first property from said first value provider in response to said first property request event and issuing a first property changed event; receiving said first property changed event and processing said first property value in response to receiving said first property changed event; receiving a second value provider; and installing said second value provider, said second value provider providing a second value for said first property and issuing a second property changed event, said second value provider executing to provide said second value based on a property request event for said first property, said installation of said second value provider being performed without changing application code for said calling routine.