Examples: Constraints

This section of the specification contains examples and scenarios. They illustrate a variety of ways that constraints can be used; they also provide examples of the DTD coding requirements for constraints and how constraints are integrated into document-type shells.

In this section:

  1. Example: Redefine the content model for the <topic> element
    In this scenario, an information architect for Acme, Incorporated wants to redefine the content model for the topic document type. She wants to omit the <abstract> element and make the <shortdesc> element required; she also wants to omit the <related-links> element and disallow topic nesting.
  2. Example: Constrain attributes for the <section> element
    In this scenario, an information architect wants to redefine the attributes for the <section> element. He wants to make the @id attribute required and omit the @spectitle attribute.
  3. Example: Constrain a domain module
    In this scenario, an information architect wants to use only a subset of the elements defined in the highlighting domain. She wants to use <b> and <i,> but not <line-through>, <overline>, <sup>, <sup>, <tt>, or <u>. She wants to integrate this constraint into the document-type shell for task.
  4. Example: Replace a base element with the domain extensions
    In this scenario, an information architect wants to remove the <ph> element but allow the extensions of <ph> that exist in the highlighting, programming, software, and user interface domains.
  5. Example: Apply multiple constraints to a single document-type shell
    You can apply multiple constraints to a single document-type shell. However, there can be only one constraint for a given element or domain.
Parent topic: Constraints