Patent ID: 7827591

Claim:
A method for causing a physical modification to a machine-readable medium having encoded thereon data representative of a hierarchy, the method comprising: making a Web page available for access by a user at a first client, the Web page including (i) locally-stored data representing the hierarchy and (ii) rules defining those modifications to a structure of the locally-stored data representing the hierarchy that any user is permitted to make to the data; receiving, from the user, instructions to modify the structure of the hierarchy in real-time; performing local rule enforcement at the first client by verifying that a proposed modification to the locally-stored data complies with the rules; and detecting at a server, in real-time, a modification to locally-stored data occurring at a second client; sending a call from the first client to the server to enforce rules involving multiple users based on detecting the modification to locally-stored data that occurred at the second client, the call being sent before the modified data has been saved to a master representation of the hierarchy on the server; and causing the physical modification of the machine-readable medium, the physical modification resulting in the master representation of the hierarchy.