XML Objectified: IDOMElement's Revisited

Despite our brief sojourn into the attributes list and its IDOMAttribute objects, we have not yet abandoned the IDOMElement object, since it is the object which reflects the XML element. To recap our latest feat, we've begun at the trunk (petfolio node), worked our way up to see each branch (pet node) and briefly peeked at the attributes associated with the latter node.

If you look closely at each pet branch in the earlier inspired illustration you'll see that each possesses five sub-branches. The leaves, in fact, are connected to each of these sub-branches. Similarly, the <pet> element in our example contains five child elements: <breed>, <color>, <age>, <weight>, and <description>. Each of these elements, then, is considered by the XML DOM to be another element node, meaning yet another IDOMNode object:

petbase.childNodes(1).childNodes(0).childNodes.length	yields	5
petbase.childNodes(1).childNodes(0).childNodes(0).nodeName	yields	"breed"
petbase.childNodes(1).childNodes(0).childNodes(1).nodeName	yields	"color"
petbase.childNodes(1).childNodes(0).childNodes(2).nodeName	yields	"age"
petbase.childNodes(1).childNodes(0).childNodes(3).nodeName	yields	"weight"
petbase.childNodes(1).childNodes(0).childNodes(4).nodeName	yields	"description"

Just to flex our syntactical muscles, then, let's take a quick peek at the units attribute of the weight node:

petbase.childNodes(1).childNodes(0).childNodes(3).attributes.getNamedItem("units")

yields

"lbs"

Whew -- if you need a Tylenol at this point that would be entirely understandable. We're way out on a limb now!

Our final goal in this lesson, then, is to reach out for that brass monkey -- the data within, the IDOMText object. The leaf nodes are within sight. In fact, each of the above nodes possesses only one child, the data itself: the leaf node.

petbase.childNodes(1).childNodes(0).childNodes(3).childNodes.length

yields

1

We know that the child node at this point is in fact a leaf node due to its nodeType, #3 NODE_TEXT, which cannot possess any children. Thus, it is an IDOMText object.

petbase.childNodes(1).childNodes(0).childNodes(3).childNodes(0).nodeType

yields

3

The end is near ... the nodeValue property will contain the data itself, the text content of the leaf which is a nodeType #3. Voila:

petbase.childNodes(1).childNodes(0).childNodes.length	yields	5
petbase.childNodes(1).childNodes(0).childNodes(0).firstChild.nodeValue	yields	"Domestic Shorthair"
petbase.childNodes(1).childNodes(0).childNodes(1).firstChild.nodeValue	yields	"black/tan tiger"
petbase.childNodes(1).childNodes(0).childNodes(2).firstChild.nodeValue	yields	"3"
petbase.childNodes(1).childNodes(0).childNodes(3).firstChild.nodeValue	yields	"1.75"
petbase.childNodes(1).childNodes(0).childNodes(4).firstChild.nodeValue	yields	"Ella is a smart, poised creature full of courage and vinegar."

Exciting stuff -- in the interest of prudence, we should note that the nodeValue property returns a string value, even if the data is numeric. In the above the leaf nodes with the data "3" and "1.75", these values are returned as strings. The length property, in contrast, is an integer.

XML Objectified: Attributes Considered
XML via the Document Object Model: A Preliminary Course
A Final Image...