NodeFilter

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Uma interface NodeFilter representa um objeto usado para filtrar os nós (elementos), em uma iteração NodeIterator ou TreeWalker. Essas interfaces não conhecem nada sobre o DOM ou sobre como percorrer ou atravessar, elementos; elas apenas sabem como avaliar se um único nó atende aos requisitos do filtro fornecido ou não.

Nota: O navegador não fornece nenhum objeto que implemente essa interface. É esperado que o desenvolvedor escreva tal objeto, utilizando o método acceptNode() conforme as suas necessidades, podendo mesclar com objetos do tipo TreeWalker ou NodeIterator em sua implementação..

Properties

Essa interface não implementa, nem herda, nenhuma propriedade.

Methods

Essa interface não herda nenhum método.

NodeFilter.acceptNode()

Returns an unsigned short that will be used to tell if a given Node must be accepted or not by the NodeIterator or TreeWalker 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. For `TreeWalker`, child nodes are also rejected. For `NodeIterator`, this flag is synonymous with FILTER_SKIP.
`FILTER_SKIP`	Value to be returned by `NodeFilter.acceptNode()` for nodes to be skipped by the `NodeIterator` or `TreeWalker` object. The children of skipped nodes are still considered. This is treated as "skip this node but not its children".

Example

var 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
var node;

while ((node = nodeIterator.nextNode())) {
  alert(node.data);
}

Specifications

Specification
DOM # dom-document-createnodeiterator