The present invention enables a three-pane page flow editor optimized for viewing and editing a page flow. It provides a visual representation of nodes and the connections among them, enabling the ability to read and edit connections between nodes in a local area of the page flow without the overlaps between lines and crossovers once the page flow grows complex in real applications. In addition, a declarative validation rule editor is operable to create and manage a plurality of declarative validation rules of the page flow and their associated messages at design time which can be used by the page flow runtime to keep the user from entering and/or submitting bad or invalid data into the page flow. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.