B. Design Goals

Contents

    B.1. Requirements
        B.1.1. Granularity
        B.1.2. Composibility
        B.1.3. Ease of Use
        B.1.4. Compatibility
        B.1.5. Conformance

This appendix is informative

There are six major design goals for the modularization framework for XHTML:

[G1] Provide a means for the W3C and third parties to integrate XHTML into other XML languages.
[G2] Provide a means for the W3C to extend XHTML with new or optional features.
[G3] Provide a means for third parties to extend XHTML with domain-specific features.
[G4] Provide a means for third parties to integrate other XML languages into XHTML.
[G5] Improve the ability to create a close approximation to the HTML 4.0 DTDs.
[G6] Improve ease-of-use for DTD developers.

B.1. Requirements

The design goals listed in the previous section lead to a large number of requirements for the modularization framework. These requirements, summarized in this section, can be further classified according to the major features of the framework to be described.

B.1.1. Granularity

Collectively the requirements in this section express the desire that the modules defined within the framework hit the right level of granularity:

[R1.1] Semantic modules should promote and maintain content portability.
[R1.2] Semantic modules should promote platform profile standardization.
[R1.3] Semantic modules should be large enough to promote interoperability.
[R1.4] Semantic modules should be small enough to avoid the need for subsets.
[R1.5] Semantic modules should collect elements with similar or related semantics.
[R1.6] Semantic modules should separate elements with dissimilar or unrelated semantics.
[R1.7] Modules should be small enough to allow single element document type modules.

B.1.2. Composibility

The composibility requirements listed here are intended to ensure that the modularization framework be able to express the right set of target modules required by the communities that will be served by the framework:

[R2.1] The module framework should allow construction of semantic modules for XHTML 1.0.
[R2.2] The module framework should allow construction of semantic modules that closely approximate HTML 4.0.
[R2.3] The module framework should allow construction of semantic modules for other W3C Recommendations.
[R2.4] The module framework should allow construction of semantic modules for other XML document types.
[R2.5] The module framework should allow construction of semantic modules for a wide range of platform profiles.

B.1.3. Ease of Use

The modularization framework will only receive widespread adoption if it describes mechanisms that make it easy for our target audience to use the framework:

[R3.1] The module framework should make it easy for document type designers to subset and extend XHTML semantic modules.
[R3.2] The module framework should make it easy for document type designers to create semantic modules for other XML document types.
[R3.3] The module framework should make it easy for document authors to validate elements from different semantic modules.

B.1.4. Compatibility

The intent of this document is that the modularization framework described here should work well with the XML and other standards being developed by the W3C Working Groups:

[R4.1] The module framework should strictly conform to the XML 1.0 Recommendation.
[R4.2] The module framework should be compatibile with the XML linking specification.
[R4.3] The module framework should be compatibile with the XML stylesheet specification.
[R4.4] The module framework should be able to adopt new W3C recommendations where appropriate.
[R4.5] The module framework should not depend on W3C work in progress.
[R4.6] The module framework should not depend on work done outside W3C.

B.1.5. Conformance

The effectiveness of the framework will also be measured by how easy it is to test the behavior of modules developed according to the framework, and to test the documents that employ those modules for validation:

[R5.1] It should be possible to validate documents constructed using elements and attributes from semantic modules.
[R5.2] It should be possible to explicitly describe the behavior of elements and attributes from semantic modules.
[R5.3] It should be possible to verify the behavior of elements and attributes from semantic modules.
[R5.4] It should be possible to verify a compound document type as an XHTML document type.
[R5.5] Modules defined in accordance with the methods in this document shall not duplicate the names of elements or parameter entities defined in XHTML modules.