The TreeWalker.whatToShow read-only property returns an unsigned long being a bitmask made of constants describing the types of Node that must to be presented. Non-matching nodes are skipped, but their children may be included, if relevant. The possible values are:
Constant
Numerical value
Description
NodeFilter.SHOW_ALL
-1 (that is the max value of unsigned long)
Shows all nodes.
NodeFilter.SHOW_ATTRIBUTE
2
Shows attribute Attr nodes. This is meaningful only when creating a TreeWalker with an Attr node as its root; in this case, it means that the attribute node will appear in the first position of the iteration or traversal. Since attributes are never children of other nodes, they do not appear when traversing over the document tree.
Shows Entity nodes. This is meaningful only when creating a TreeWalker with an Entity node as its root; in this case, it means that the Entity node will appear in the first position of the traversal. Since entities are not part of the document tree, they do not appear when traversing over the document tree.
Shows Notation nodes. This is meaningful only when creating a TreeWalker with a Notation node as its root; in this case, it means that the Notation node will appear in the first position of the traversal. Since entities are not part of the document tree, they do not appear when traversing over the document tree.