TreeWalker.whatToShow

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.
NodeFilter.SHOW_CDATA_SECTION 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 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 16 Shows EntityReference nodes.
NodeFilter.SHOW_NOTATION 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.

Syntax

nodeTypes = treeWalker.whatToShow;

Example

var treeWalker = document.createTreeWalker(
    document.body,
    NodeFilter.SHOW_ELEMENT + NodeFilter.SHOW_COMMENT + NodeFilter.SHOW_TEXT,
    { acceptNode: function(node) { return NodeFilter.FILTER_ACCEPT; } },
    false
);
if( (treeWalker.whatToShow == NodeFilter.SHOW_ALL) ||
    (treeWalker.whatToShow % (NodeFilter.SHOW_COMMENT*2)) >= NodeFilter.SHOW_COMMENT) {
    // treeWalker will show comments
}

Specifications

Specification Status Comment
DOM
The definition of 'TreeWalker.whatToShow' in that specification.		 Living Standard No change from Document Object Model (DOM) Level 2 Traversal and Range Specification
Document Object Model (DOM) Level 2 Traversal and Range Specification
The definition of 'TreeWalker.whatToShow' in that specification.		 Obsolete Initial definition.

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
whatToShowChrome Full support 1Edge Full support 12Firefox Full support 4IE Full support 9Opera Full support 9Safari Full support 3WebView Android Full support 3Chrome Android Full support YesFirefox Android Full support 4Opera Android Full support 10.1Safari iOS Full support 3Samsung Internet Android Full support Yes

Legend

Full support
Full support

See also