RELAX NG

Spreadsheets

The final transformation I’ll show here is much more widely used than you might think. Spreadsheets are familiar, very convenient to store, can manipulate large lists of information items, and have been used as a modeling tool for many years. The UBL OASIS Technical Committee (see http://www.oasis-open.org/committees/ubl/), which is in charge of a set of core components to be used by B2B applications and frameworks such as ebXML, has moved in this direction. Although this project uses a UML methodology, the release note of their 0.70 version states: “The current spreadsheet matrix used by UBL has proved the most versatile and manageable in developing a logical model of the UBL Library.”

Recent spreadsheet software can work with XML formats, so generating RELAX NG schemas from such a tool is really easy.

Tip

There is no standard way to represent XML documents in a spreadsheet. Thus the benefit of spreadsheets is their flexibility: you can define layouts specific to each application.

Coming back to our library, we can formalize it in an OpenOffice spreadsheet as shown in Figure 14-7.

Figure 14-7. The library document structure, described in a spreadsheet

Figure 14-7 is basically nothing more than a catalog of each information item with just enough information to generate a schema. The benefit of using a spreadsheet is that it’s easy to read and, when the catalog gets bigger, ...