The TreeWalker object represents the nodes of a document subtree and a position within them.
Documentation TreeWalker by Mozilla Contributors, licensed under CC-BY-SA 2.5.
See also:
Variables
read onlyfilter:EitherType<Node ‑> Int, NodeFilter>
Returns a NodeFilter used to select the relevant nodes.
read onlyroot:Node
Returns a Node representing the root node as specified when the TreeWalker was created.
read onlywhatToShow:Int
Returns an unsigned long being a bitmask made of constants describing the types of Node that must 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 {{deprecated_inline}} |
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. |
NodeFilter.SHOW_CDATA_SECTION {{deprecated_inline}} |
8 |
Shows CDATASection nodes. |
NodeFilter.SHOW_COMMENT |
128 |
Shows Comment nodes. |
NodeFilter.SHOW_DOCUMENT |
256 |
Shows Document nodes. |
NodeFilter.SHOW_DOCUMENT_FRAGMENT |
1024 |
Shows DocumentFragment nodes. |
NodeFilter.SHOW_DOCUMENT_TYPE |
512 |
Shows DocumentType nodes. |
NodeFilter.SHOW_ELEMENT |
1 |
Shows Element nodes. |
NodeFilter.SHOW_ENTITY {{deprecated_inline}} |
32 |
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. |
NodeFilter.SHOW_ENTITY_REFERENCE {{deprecated_inline}} |
16 |
Shows EntityReference nodes. |
NodeFilter.SHOW_NOTATION {{deprecated_inline}} |
2048 |
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. |
NodeFilter.SHOW_PROCESSING_INSTRUCTION |
64 |
Shows ProcessingInstruction nodes. |
NodeFilter.SHOW_TEXT |
4 |
Shows Text nodes. |
Methods
firstChild():Node
Moves the current Node to the first visible child of the current node, and returns the found child. It also moves the current node to this child. If no such child exists, returns null and the current node is not changed.
Throws:
null | DOMError |
|---|
lastChild():Node
Moves the current Node to the last visible child of the current node, and returns the found child. It also moves the current node to this child. If no such child exists, null is returned and the current node is not changed.
Throws:
null | DOMError |
|---|
nextNode():Node
Moves the current Node to the next visible node in the document order, and returns the found node. It also moves the current node to this one. If no such node exists, returns null and the current node is not changed.
Throws:
null | DOMError |
|---|
nextSibling():Node
Moves the current Node to its next sibling, if any, and returns the found sibling. If there is no such node, null is returned and the current node is not changed.
Throws:
null | DOMError |
|---|
parentNode():Node
Moves the current Node to the first visible ancestor node in the document order, and returns the found node. It also moves the current node to this one. If no such node exists, or if it is before that the root node defined at the object construction, returns null and the current node is not changed.
Throws:
null | DOMError |
|---|
previousNode():Node
Moves the current Node to the previous visible node in the document order, and returns the found node. It also moves the current node to this one. If no such node exists, or if it is before that the root node defined at the object construction, returns null and the current node is not changed.
Throws:
null | DOMError |
|---|
previousSibling():Node
Moves the current Node to its previous sibling, if any, and returns the found sibling. If there is no such node, return null and the current node is not changed.
Throws:
null | DOMError |
|---|