Document: createNodeIterator() method

Syntax

createNodeIterator(root)
createNodeIterator(root, whatToShow)
createNodeIterator(root, whatToShow, filter)

Parameters

root

The root node at which to begin the NodeIterator's traversal.

whatToShow Optional

An optional unsigned long representing a bitmask created by combining the constant properties of NodeFilter. It is a convenient way of filtering for certain types of node. It defaults to 0xFFFFFFFF representing the SHOW_ALL constant.

Constant	Numerical value	Description
NodeFilter.SHOW_ALL	0xFFFFFFFF	Shows all nodes.
NodeFilter.SHOW_ATTRIBUTE	0x2	Shows Attr nodes.
NodeFilter.SHOW_CDATA_SECTION	0x8	Shows CDATASection nodes.
NodeFilter.SHOW_COMMENT	0x80	Shows Comment nodes.
NodeFilter.SHOW_DOCUMENT	0x100	Shows Document nodes.
NodeFilter.SHOW_DOCUMENT_FRAGMENT	0x400	Shows DocumentFragment nodes.
NodeFilter.SHOW_DOCUMENT_TYPE	0x200	Shows DocumentType nodes.
NodeFilter.SHOW_ELEMENT	0x1	Shows Element nodes.
NodeFilter.SHOW_ENTITY Deprecated	0x20	Legacy, no longer effective.
NodeFilter.SHOW_ENTITY_REFERENCE Deprecated	0x10	Legacy, no longer effective.
NodeFilter.SHOW_NOTATION Deprecated	0x800	Legacy, no longer effective.
NodeFilter.SHOW_PROCESSING_INSTRUCTION	0x40	Shows ProcessingInstruction nodes.
NodeFilter.SHOW_TEXT	0x4	Shows Text nodes.

Note: The NodeFilter.SHOW_ATTRIBUTE constant is only effective when the root is an attribute node. Since the parent of any Attr node is always null, TreeWalker.nextNode() and TreeWalker.previousNode() will never return an Attr node. To traverse Attr nodes, use Element.attributes instead.

filter Optional

A callback function or an object with an acceptNode() method. The function or method will be called for each node in the subtree based at root which is accepted as included by the whatToShow flag to determine whether or not to include it in the list of iterable nodes. The method should return one of NodeFilter.FILTER_ACCEPT, NodeFilter.FILTER_REJECT, or NodeFilter.FILTER_SKIP. See the Example.

For createNodeIterator, the values NodeFilter.FILTER_REJECT and NodeFilter.FILTER_SKIP are equivalent. This node will not be included in the list of iterable nodes, but its children will continue to be iterated over.

Return value

A new NodeIterator object.

Examples

const nodeIterator = document.createNodeIterator(
  document.body,
  NodeFilter.SHOW_ELEMENT,
  (node) =>
    node.nodeName.toLowerCase() === "p"
      ? NodeFilter.FILTER_ACCEPT
      : NodeFilter.FILTER_REJECT,
);
const pars = [];
let currentNode;

while ((currentNode = nodeIterator.nextNode())) {
  pars.push(currentNode);
}

The same, but using an object with an acceptNode() method:

const nodeIterator = document.createNodeIterator(
  document.body,
  NodeFilter.SHOW_ELEMENT,
  {
    acceptNode(node) {
      return node.nodeName.toLowerCase() === "p"
        ? NodeFilter.FILTER_ACCEPT
        : NodeFilter.FILTER_REJECT;
    },
  },
);
const pars = [];
let currentNode;

while ((currentNode = nodeIterator.nextNode())) {
  pars.push(currentNode);
}

Specifications

Browser compatibility