Rules and conditional publishing
In Elepub rule based publishing and conditional publishing are separate complementary features - once more opposed to conventional database publishing. Although both features provide something quite similar, they do this in a very different way.
Rule based formatting
Elepub objects are rule based. Every object can contain virtually any needed rule. Pages are built from such objects. Therefore, the format used for publishing can depend on such rules, which are either determined when a page is generated or, in electronic applications, much later in usage time when a page is presented.
This is especially useful when creating publications for Elecat, the CDF based (Catalog Data Format) electronic product catalog, which can interpret the rules inherent to Elepub objects and therefore format the particular layout as the rules say, i.e. situation dependent.
Of course, the powerful feature of exchanging contents on page (as explained here can also be used to completely hide certain data from a page and to show it only under certain conditions. This is what in Elepub is called conditional publishing, another Elepub feature unknown to conventional database publishing where this can only be achieved with great complications.
This Elepub feature enables many new opportunities like using the basically same layout for several output results and/or to better utilize one layout for different media each using the media's best capabilities. Some examples are:
- publish a paper version of a product catalog without prices
- publish the same catalog to electronic paper with prices included
- include references to a database or to a web server in layout for electronic use, while the same layout is used for paper output with disabled references