javascript

CHAPTER 7 ■ TRAVERSING AND MODIFYING THE DOM TREE
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Figure 7–10. Using traverseTree() to convert the text of our list items to lowercase
One final note on traverseTree(): although you stepped through child nodes by way of firstChild
and nextSibling, you could have done so with lastChild and previousSibling, too. Click the Refresh
icon in Firefox to revert the text in the elements to that from our markup, and then simply edit
traverseTree(), changing firstChild to lastChild and nextSibling to previousSibling. Click Run to
verify that traverseTree() works just as well traversing child nodes in reverse. More often than not, you
will traverse child nodes moving forward with nextSibling rather than in reverse with previousSibling.
function traverseTree(node, func) {
func(node);
node = node.lastChild;
while (node !== null) {
arguments.callee(node, func);
node = node.previousSibling;
}
}
var root = document.
childNodes[1].
childNodes[1].
childNodes[1].
childNodes[3];
traverseTree(root, function(node) {
if (node.nodeType === 3) {
node.data = node.data.toLowerCase();
}
});