Retrospective
Exceptions during wrapping
- Logically homogenous pages may be physically heterogeneous
- Different ways of laying out the same information
- Errors masked by browsers
ULIXES syntax is difficult for beginners
- Alternatives
- Fill out forms corresponding to pre-determined ULIXES queries
- Developed POLYPHEMUS query interface
- User selects path for query by clicking on graphical representation of ADM page schemes
Push vs. Pull
- Either supported; hybrid model preferred
- Dealing with updates
- each DB update generates a mixed transaction that updates both the DB and any pushed (static) HTML pages
Managing internal sites
- PENELOPE-generated HTML includes description of page scheme and tags attributes
- Like XML but uses HTML comments