Repository of inheritable mother objects

ElePub comes with a well-equipped repository of generic and re-usable mother objects, containers, frames, tables, table cells and all other object types. You can easily modify and extent these objects to support your specific needs. Just create new mother objects with slightly changed attributes by inheriting from the existing ones.

When real pages are created, whether automatically by the page generator or manually designed, what really happens is that children from existing mother objects are created and placed in a container on some page. These newly created children re-use most of the attributes defined in their mother objects. They only slightly differ from their mothers in exactly those attributes, which are different from their particular mother object.

In this simplified example a mother frame for visualizing an article number is defined in the repository. Of course, the mother object has no own data but contains instead an object (data link object) creating a link into EleStore or, indirectly via the data link objects in EleStore, into your existing database.

When a real page is build, a child is created from this mother object and placed on this page (or rather inside a container, as you will see in the next chapter). This child typically only differs from its mother in some few attributes, always in the location on a page, often in size, and rarely in some few other attributes.

The child shows a data value because it not only inherits a data link from the mother frame, but also additionally receives an unique identifier (primary key) of a particular record in the database. This is why the article number shows up automatically on the real page whereas the mother object only has a data link object without an identifier (symbolized in the above drawing by the dotted line in the repository) and therefore is also without a real value.

Creating pages as a composed collection of inherited children of mother objects is the first practical usage of object inheritance in the publishing field. This can impossibly be achieved with today's DTP software but only through ElePub's own object-oriented page and visualization object structures. This is another reason why ElePub has its own pages and page editor and why ElePub can do entirely without DTP (unless 4-color separation is required).