Updating local copy of shared data in a collaborative system

A multi-user collaborative system in which the contents as well as the current status of other user activity of a shared structured data object representing one or more related structured data objects in the form of data entries can be concurrently accessed by different users respectively at different workstations connected to a common link. The WYSIWIS user interface representation of the shared structured data object includes an ordered listing of such entries that are maintained by the structured data object and various attributes of each listed entry, inter alia, the type and class of entry; the revision number of the shared structured data object; the number of pages and revision number of each structured data object entry; the date of creation and last revision of each such entry; whether an entry can be accessed by a user and, if not, who has prevented such access; whether a local instance of an entry is present on a user's system; and a provision for miscellaneous notes or comments relative to each entry for view by other users. Means is provided for maintaining current information relative to the shared structured object and its entries on a user initiated demand updated basis invoked by a user operation, which operation requires updated information to properly implement the operation. Further, means is provided for locking up one or more data entries by an individual user and thereby prevent access of the locked entries by other users to prevent concurrent editing and other changes to the same entries by two or more users. In this connection, editing or modification cannot be performed by a user until the shared structured data object entry or entries have been locked up. Visual indication as to the locked state of entries and other information relative to the locking user and the time of lock is updated and displayed in the shared structured data object representation present at user workstations when a use invokes a user operation on the shared structured data object or its contents.