2. Requirements

The design and specification of the SMIL DOM must meet the following set of requirements.

General requirements:

• Inherit DOM Level 2 core functionality - the SMIL DOM will be based upon the generic Core DOM foundation.
• Support constraints on DOM core functionality (e.g. mutation), especially at runtime.
• Support both SMIL documents as well as hybrid documents that integrate XML/HTML and SMIL functionality.
• Support and reflect the modularization of SMIL functionality. It must be possible to design hybrid documents combining XML/HTML and SMIL functionality, that can in turn support a hybrid or combined DOM.

SMIL specific requirements:

• Support SMIL specific elements. It must be possible to access and manipulate all SMIL elements within a SMIL document or a hybrid document that integrates XML and SMIL modules.
• Support SMIL specific attributes and methods. It must be possible to access and manipulate the SMIL attributes and methods on SMIL elements as well as XML/HTML elements in a hybrid documents.
• Support SMIL specific events, including:
  • Specification of statically defined SMIL events
  • Support for dynamically defined events
  • The ability to create and raise all the above events
• Support SMIL semantics. This includes various constraints on document structure, attribute values and method invocation.
• Define basic control interface for media player/renderers. Do not define a plug-in API, but rather just the timing and sync control interface.

It is not yet clear what all the requirements ([DOM Requirements]) on the SMIL DOM will be related to the modularization of SMIL functionality. While the HTML Working Group is also working on modularization of XHTML, a modularized HTML DOM is yet to be defined. In addition, there is no general mechanism yet defined for combining DOM modules for a particular profile.