1. A method comprising: defining a document model, wherein the document model includes: a header model including a set of header methods to provide interaction capabilities to other portions of a system, one or more item models, including a set of item methods to provide interaction capabilities to other portions of the system, wherein the header model and the one or more item models each include an association with one or more component models, and wherein each component model includes: a set of component methods to provide interaction capabilities to other portions of the system, and component specific logic accessible through the component methods.