This page maps the classes in the xg package to the Java interfaces in the Document Object Model (DOM). There is a reasonable correlation (it would be a worry if there wasn't!). Although xg currently supports only one of the DOM interfaces, it is intended to gradually implement them, and so slowly move towards DOM compliance (though full DOM compliance is not a strong goal and may never be achieved). Compliance to DOM is currently measured against the W3C Working Draft 18 March 1998.

DOM Level 1 Core
 
 

DOM Interface	xg Class	Notes on compliance
DOM	No direct equivalent - the closest being the xe package	Does not comply.
DocumentContext	No direct equivalent	Does not comply.
DocumentFragment	No direct equivalent	Does not comply. Potentially a useful addition for xe, in order to manipulate a selected portion of a document.
Document	xg_Document	Does not comply. xg_Document does not create other objects. While this is easy enough to do for fixed types, in the xe environment, we want to be able to instantiate objects of other types - functionality which is implemented at the xe level.
Node	xg_Node	Does not comply. Reasonably straightforward to implement, although xg_Node currently has no notion of 'current' node (and it sounds a rather untidy idea to have to do so).
NodeIterator	No direct equivalent	Does not comply.
TreeIterator	No direct equivalent	Does not comply.
Attribute	xg_Attribute	Complies. Note, however, that the current xe implementation only creates attributes if they are explicitly specified (ie. defaults are not created as defined in the DTD).
AttributeList	xg_AttList	Complies.
Element	xg_Element	Does not comply. Reasonably straightforward mapping, although with what look like a few fiddly differences (eg. DOM setAttribute equates to xg_Element.addAttribute, but its behaviour if an attribute with this name already exists is different). xg_Element has no equivalent to the normalize method.
Text	xg_Text	Does not comply. xg_Text has none of the DOM text manipulation functions, although these are easy to implement.
Comment	xg_Comment	Does not comply.
PI	xg_PI	Does not comply.

 

DOM Level 1 XML
 
 

DOM Interface	xg Class	Notes on compliance
XMLNode	xg_Node	Does not comply. xg_Node currently lacks the ability to relate to parts of the DTD which relate to it, and also does not properly handle entity references. As above, xg_Node has no notion of 'current' node (and no wish to!).
DocumentType	xg_Dtd	Does not comply. xg_Dtd is currently very simple, and is basically just a collection of its parts. In enhancing it to a level of reasonable usefulness, DOM compliance should be possible with little difficulty.
ElementDefinition	xg_ElementDecl	Does not comply. While able to parse an element declaration, xg does not properly record the details of what was parsed.
PCDATAToken	No direct equivalent	Does not comply.An equivalent needs to be added to xg in order to properly model element declarations, so DOM compliance could be added at this time.
ElementToken	No direct equivalent	Does not comply. As for PCDATAToken
ModelGroup	No direct equivalent	Does not comply. As for PCDATAToken
AttributeDefinition	xg_AttDecl	Does not comply. xg_AttDecl is currently too simple for practical use.
Notation	No direct equivalent	Does not comply.
EntityDeclaration	xg_EntityDecl	Does not comply.
EntityReference	xg_Reference	Does not comply. xg currently lacks proper support for references, including reference expansion.
CDATASection	xg_Cdata	Does not comply.