## org.w3c.dom.traversal
Interface NodeFilter

All Known Subinterfaces:
  LSSerializerFilter

public interface NodeFilter

Filters are objects that know how to "filter out" nodes. If a `NodeIterator` or `TreeWalker` is given a `NodeFilter`, it applies the filter before it returns the next node. If the filter says to accept the node, the traversal logic returns it; otherwise, traversal looks for the next node and pretends that the node that was rejected was not there.

The DOM does not provide any filters. `NodeFilter` is just an interface that users can implement to provide their own filters.

`NodeFilters` do not need to know how to traverse from node to node, nor do they need to know anything about the data structure that is being traversed. This makes it very easy to write filters, since the only thing they have to know how to do is evaluate a single node. One filter may be used with a number of different kinds of traversals, encouraging code reuse.

See also the Document Object Model (DOM) Level 2 Traversal and Range Specification.

Since:
  DOM Level 2

Field Summary
`static short` `FILTER_ACCEPT` Accept the node.
`static short` `FILTER_REJECT` Reject the node.
`static short` `FILTER_SKIP` Skip this single node.
`static int` `SHOW_ALL` Show all `Nodes`.
`static int` `SHOW_ATTRIBUTE` Show `Attr` nodes.
`static int` `SHOW_CDATA_SECTION` Show `CDATASection` nodes.
`static int` `SHOW_COMMENT` Show `Comment` nodes.
`static int` `SHOW_DOCUMENT` Show `Document` nodes.
`static int` `SHOW_DOCUMENT_FRAGMENT` Show `DocumentFragment` nodes.
`static int` `SHOW_DOCUMENT_TYPE` Show `DocumentType` nodes.
`static int` `SHOW_ELEMENT` Show `Element` nodes.
`static int` `SHOW_ENTITY` Show `Entity` nodes.
`static int` `SHOW_ENTITY_REFERENCE` Show `EntityReference` nodes.
`static int` `SHOW_NOTATION` Show `Notation` nodes.
`static int` `SHOW_PROCESSING_INSTRUCTION` Show `ProcessingInstruction` nodes.
`static int` `SHOW_TEXT` Show `Text` nodes.

Method Summary
`short` `acceptNode(Node n)` Test whether a specified node is visible in the logical view of a `TreeWalker` or `NodeIterator`.

Field Detail

### FILTER_ACCEPT

    public static final short FILTER_ACCEPT

  Accept the node. Navigation methods defined for `NodeIterator` or `TreeWalker` will return this node.

### FILTER_REJECT

    public static final short FILTER_REJECT

  Reject the node. Navigation methods defined for `NodeIterator` or `TreeWalker` will not return this node. For `TreeWalker`, the children of this node will also be rejected. `NodeIterators` treat this as a synonym for `FILTER_SKIP`.

### FILTER_SKIP

    public static final short FILTER_SKIP

  Skip this single node. Navigation methods defined for `NodeIterator` or `TreeWalker` will not return this node. For both `NodeIterator` and `TreeWalker`, the children of this node will still be considered.

### SHOW_ALL

    public static final int SHOW_ALL

  Show all `Nodes`.

### SHOW_ELEMENT

    public static final int SHOW_ELEMENT

  Show `Element` nodes.

### SHOW_ATTRIBUTE

    public static final int SHOW_ATTRIBUTE

  Show `Attr` nodes. This is meaningful only when creating an `NodeIterator` or `TreeWalker` with an attribute 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.

### SHOW_TEXT

    public static final int SHOW_TEXT

  Show `Text` nodes.

### SHOW_CDATA_SECTION

    public static final int SHOW_CDATA_SECTION

  Show `CDATASection` nodes.

### SHOW_ENTITY_REFERENCE

    public static final int SHOW_ENTITY_REFERENCE

  Show `EntityReference` nodes.

### SHOW_ENTITY

    public static final int SHOW_ENTITY

  Show `Entity` nodes. This is meaningful only when creating an `NodeIterator` or `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.

### SHOW_PROCESSING_INSTRUCTION

    public static final int SHOW_PROCESSING_INSTRUCTION

  Show `ProcessingInstruction` nodes.

### SHOW_COMMENT

    public static final int SHOW_COMMENT

  Show `Comment` nodes.

### SHOW_DOCUMENT

    public static final int SHOW_DOCUMENT

  Show `Document` nodes.

### SHOW_DOCUMENT_TYPE

    public static final int SHOW_DOCUMENT_TYPE

  Show `DocumentType` nodes.

### SHOW_DOCUMENT_FRAGMENT

    public static final int SHOW_DOCUMENT_FRAGMENT

  Show `DocumentFragment` nodes.

### SHOW_NOTATION

    public static final int SHOW_NOTATION

  Show `Notation` nodes. This is meaningful only when creating an `NodeIterator` or `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 notations are not part of the document tree, they do not appear when traversing over the document tree.

Method Detail

### acceptNode

    public short acceptNode(Node n)

  Test whether a specified node is visible in the logical view of a `TreeWalker` or `NodeIterator`. This function will be called by the implementation of `TreeWalker` and `NodeIterator`; it is not normally called directly from user code. (Though you could do so if you wanted to use the same filter to guide your own application logic.)
  Parameters:
    `n` - The node to check to see if it passes the filter or not.
  Returns:
    A constant to determine whether the node is accepted, rejected, or skipped, as defined above.

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