1. A method for web application navigation control, comprising: updating navigation data models used in navigation constraints with received data from an end-user or system, the data models being stored on a computer storage medium; without needing a centralized application-specific controller, automatically selecting from a collection of extensible navigation rules associated with each page of a plurality of pages the extensible navigation rules; evaluating the navigation constraints associated only with the pages potentially changing their ready state to execute from among the plurality of pages in an entire application to determine which pages are ready to run, wherein determining which pages are ready to run is based on updated data from the navigation data models; and selecting a preferred page to be actually navigated to next from among a set of all available and ready pages.