2. Document Object Model (Core) Level 1

2.6 Auxiliary types

These types are "helpers" which can appear in various parts of the DOM. Some of them occur quite frequently in common usage; others are limited to the Document Type Definition section of the document, and thus may be of little interest to typical DOM users. Those types are marked accordingly.

2.6.1 NodeIterator

The NodeIterator object is used for iterating over a set of nodes specified by a "filter". Iterators are described in detail in the book Design Patterns, pages 257-271, from which the following sections are quoted:

Intent

Provide a way to access elements of an aggregate object sequentially without exposing its underlying representation.

Applicability

Use the Iterator pattern

• to access an aggregate object's content without exposing its internal representation.
• to support multiple traversals of aggregate objects.
• to provide a uniform interface for traversing different aggregate structures (that is, to support polymorphic iteration).

2.6.2 AttributeList

The AttributeList object represents a collection of Attribute objects, indexed by attribute name.

2.6.3 DocumentContext

The DocumentContext object is repository for meta-data about a document, such as source, creation date, and other creation context information. This object will be fully specified in the level two DOM specification.

2.6.4 DOM

The DOM object provides document basic operations such as creating new top-level HTML or XML documents, or making inquiries about specific supported versions of HTML and XML within a particular document object model implementation.

2.6.5 Range

The Range object [Being discussed for possible inclusion in a later draft of level one] represents a part of the document, potentially including markup.