1. A method implemented in computer-executable instructions that, when executed by a computer processor, sets a rule associated with a user interface component in a data model, the method comprising: instantiating a runtime object that implements computational logic of the user interface component; if the user interface component is a rule user, allocating a namespace to rules of the user interface component in the data model; applying rules of the user interface component through the execution of a rule handler; merging the rule associated with the user interface component into the data model, the rule being merged into the data model in a namespace that is separate from a namespace associated with a different component; and in response to a modification to the data model: receiving a variable describing a location in the data model that was modified; and if the rules in the data model were modified, executing the rule handler to ensure integrity of the data model relative to the user interface component; wherein the modification to the data model is represented in a plurality of objects, each object providing an XBind that references a location in an XML document where a modification to the data model occurred.