XML Objectified: IDOMNode's

You may be wondering, incidentally, if you can tell the type of a particular node. For instance, what if you did not know ahead of time which of these two nodes was the processing instruction? Not a problem!

The IDOMNode object, which we now begin to explore more closely, possesses a property named nodeType. By inspecting the nodeType of a particular node we can learn what sort of data it may possess, and whether or not it is able to have any children of its own.

Returning to our example:

petbase.childNodes(0).nodeType	yields	7 (NODE_PROCESSING_INSTRUCTION)
petbase.childNodes(1).nodeType	yields	1 (NODE_ELEMENT)

The question begs ... how do you know what a node type 7 or 1 means? Simple, at Microsoft's XML DOM reference page for the nodeType property.

From these nodeType properties we have also learned two additional facts: the first node is, in addition to being an IDOMNode object, also an IDOMProcessingInstruction object. The second node, in contrast, is both an IDOMNode object and an IDOMElement object. As you can see, although each node is an IDOMNode object, it is also a more specific object depending upon its type. Below is a handy summary of the types of objects which an IDOMNode can be:

IDOMAttribute	Attribute object. Represents an attribute of an XML element.
IDOMCDATASection	Reflects "quoted" or "escaped" blocks of text so that that text is not interpreted as markup.
IDOMCharacterData	Text manipulation methods used by several objects.
IDOMComment	Content of an XML comment.
IDOMDocumentFragment	An object used when inserting data into the XML tree.
IDOMDocumentType	Information associated with the document type declaration, or DTD.
IDOMElement	Reflects an XML element, the most common object in an XML tree.
IDOMEntity	A parsed or unparsed entity in the XML document.
IDOMEntityReference	An entity reference node.
IDOMNotation	Contains a notation declared in the DTD or schema, such as the format of unparsed entities, the format of elements that bear a notation attribute, or the application to which a processing instruction is addressed.
IDOMProcessingInstruction	Reflects a "processing instruction," data intended for the XML processor contained in the document text.
IDOMText	The data: text content of an element or attribute.

Exploring the reference links attached to each object in the above table you will see that different types of objects support different sets of properties, methods, and so forth. This is perfectly logical -- a processing instruction node doesn't contain the same type of data as an element node, for example.

XML Objectified: IDOMDocument
XML via the Document Object Model: A Preliminary Course
XML Objectified: IDOMElement