NodeFilter
A NodeFilter
interface represents an object used to filter the nodes in a NodeIterator
or TreeWalker
. A NodeFilter
knows nothing about the document or traversing nodes; it only knows how to evaluate a single node against the provided filter.
Note: The browser doesn't provide any object implementing this interface. It is the user who is expected to write one, tailoring the acceptNode()
method to its needs, and using it with some TreeWalker
or NodeIterator
objects.
Properties
This interface neither implements nor inherits any properties.
Methods
This interface doesn't inherit any methods.
NodeFilter.acceptNode()
-
Returns an
unsigned short
that will be used to tell if a givenNode
must be accepted or not by theNodeIterator
orTreeWalker
iteration algorithm.This method is expected to be written by the user of a
NodeFilter
. Possible return values are:Constant Description FILTER_ACCEPT
Value returned by the NodeFilter.acceptNode()
method when a node should be accepted.FILTER_REJECT
Value to be returned by the
NodeFilter.acceptNode()
method when a node should be rejected. ForTreeWalker
, child nodes are also rejected.For
NodeIterator
, this flag is synonymous withFILTER_SKIP
.FILTER_SKIP
Value to be returned by
NodeFilter.acceptNode()
for nodes to be skipped by theNodeIterator
orTreeWalker
object.The children of skipped nodes are still considered. This is treated as "skip this node but not its children".
Example
const nodeIterator = document.createNodeIterator(
// Node to use as root
document.getElementById('someId'),
// Only consider nodes that are text nodes (nodeType 3)
NodeFilter.SHOW_TEXT,
// Object containing the function to use for the acceptNode method
// of the NodeFilter
{
acceptNode: function(node) {
// Logic to determine whether to accept, reject or skip node
// In this case, only accept nodes that have content
// other than whitespace
if (/\S/.test(node.data)) {
return NodeFilter.FILTER_ACCEPT
}
}
},
false
);
// Show the content of every non-empty text node that is a child of root
let node;
while ((node = nodeIterator.nextNode())) {
alert(node.data)
}
Specifications
Specification |
---|
DOM Standard # interface-nodefilter |
Browser compatibility
BCD tables only load in the browser
See also
- Related interfaces