Pros and cons of this approach


  • It works


  • Time consuming

    • Schema needs to be downloaded, converted, adjusted

    • This creates a branch of the original schemas which needs to be maintained and kept in sync with the source

    • Adding new language to our schema requires adjustments in the parent (XHTML) schema

  • Knowledge demanding

    • Only someone how knows very well a complex language like W3C XML Schema is able to create and maintain such compound schemas

  • Not reusable

    • We can't just reuse existing schemas for involved grammars (conversion, adjustments)

    • Our adjusted schemas are not easy to reuse for a different compound language. For example, in case XHTML should be embedded in SVG (other way around), we need to change a lot in our schemas and again create and maintain a branch.

  • Difficult to understand

    • Constraints for the Compound language are hard-coded within constraints for the individual languages.

    • This is difficult to read and understand