NodeDescendants (STIL)

java.lang.Object
- uk.ac.starlink.util.NodeDescendants

```
public class NodeDescendants
extends java.lang.Object
```
Represents the set of Nodes in the tree rooted at a particular DOM Node. The tree includes the root node.
This supports two ways of traversing the tree, either using an iterator, or providing an object which visits each node in the tree in turn.
Note that the iterator() and visitTree(uk.ac.starlink.util.NodeDescendants.Visitor) methods below share state -- namely the state which this object represents -- so you should not use simultaneously the result of two such method calls on the same object.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static interface NodeDescendants.Visitor
The Visitor processes a single node in a tree.

Nested Classes
Modifier and Type	Class and Description
`static interface`	`NodeDescendants.Visitor` The `Visitor` processes a single node in a tree.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`SHOW_ALL` Indicates that all nodes should be included in a traversal of, or iteration through, a tree.
`static int`	`SHOW_ATTRIBUTE`
`static int`	`SHOW_CDATA_SECTION`
`static int`	`SHOW_COMMENT`
`static int`	`SHOW_DOCUMENT`
`static int`	`SHOW_DOCUMENT_FRAGMENT`
`static int`	`SHOW_DOCUMENT_TYPE`
`static int`	`SHOW_ELEMENT`
`static int`	`SHOW_ENTITY`
`static int`	`SHOW_ENTITY_REFERENCE`
`static int`	`SHOW_NOTATION`
`static int`	`SHOW_PROCESSING_INSTRUCTION`
`static int`	`SHOW_TEXT`

Constructor Summary

Constructors
Constructor and Description
`NodeDescendants(org.w3c.dom.Node node)` Creates a new `NodeDescendant` object.
`NodeDescendants(org.w3c.dom.Node node, int whatToShow)` Creates a new `NodeDescendant` object.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`java.util.Iterator<org.w3c.dom.Node>`	`iterator()` Obtains an iterator which iterates over the nodes in the set of descendants.
`void`	`reset()` Sets the object back to its initial state.
`void`	`reset(int whatToShow)` Sets the object back to its initial state, but with a (possibly) different constraint on which nodes are included in the set.
`java.lang.Object`	`visitTree(NodeDescendants.Visitor v)` Visits each of the nodes in the tree.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SHOW_ALL
```
public static final int SHOW_ALL
```
    Indicates that all nodes should be included in a traversal of, or iteration through, a tree. To visit only certain nodes, use one of the other SHOW... constants.
    Note: this mechanism is taken from the DOM2 Traversal specification, though it is not an implementation of that set of interfaces. As noted there, not all of the SHOW... values are useful, since not all of the associated Node types can appear as descendants of a Node, othe than in rather special circumstances. The constants are included here for completeness, however.
    
    See Also:
    
    NodeDescendants(Node,int), Constant Field Values
  - SHOW_ELEMENT
```
public static final int SHOW_ELEMENT
```
    See Also:
    
    Constant Field Values
  - SHOW_ATTRIBUTE
```
public static final int SHOW_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - SHOW_TEXT
```
public static final int SHOW_TEXT
```
    See Also:
    
    Constant Field Values
  - SHOW_CDATA_SECTION
```
public static final int SHOW_CDATA_SECTION
```
    See Also:
    
    Constant Field Values
  - SHOW_ENTITY_REFERENCE
```
public static final int SHOW_ENTITY_REFERENCE
```
    See Also:
    
    Constant Field Values
  - SHOW_ENTITY
```
public static final int SHOW_ENTITY
```
    See Also:
    
    Constant Field Values
  - SHOW_PROCESSING_INSTRUCTION
```
public static final int SHOW_PROCESSING_INSTRUCTION
```
    See Also:
    
    Constant Field Values
  - SHOW_COMMENT
```
public static final int SHOW_COMMENT
```
    See Also:
    
    Constant Field Values
  - SHOW_DOCUMENT
```
public static final int SHOW_DOCUMENT
```
    See Also:
    
    Constant Field Values
  - SHOW_DOCUMENT_TYPE
```
public static final int SHOW_DOCUMENT_TYPE
```
    See Also:
    
    Constant Field Values
  - SHOW_DOCUMENT_FRAGMENT
```
public static final int SHOW_DOCUMENT_FRAGMENT
```
    See Also:
    
    Constant Field Values
  - SHOW_NOTATION
```
public static final int SHOW_NOTATION
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - NodeDescendants
```
public NodeDescendants(org.w3c.dom.Node node)
```
    Creates a new NodeDescendant object. Equivalent to NodeDescendant(node, SHOW_ALL).
    
    Parameters:
    
    node - the node which is to be the root of the tree
  - NodeDescendants
```
public NodeDescendants(org.w3c.dom.Node node,
                       int whatToShow)
```
    Creates a new NodeDescendant object. This represents the set of Nodes in the tree rooted at the given Node.
    You can configure the set to include only certain nodes. If the whatToShow parameter is given as SHOW_ALL, then all nodes are returned. If the parameter has one of the other SHOW_... values, or more than one or'ed together (using |), then only the indicated node types are included in the set, and returned by any iterator or examined by any visitor.
    For example, if you create the NodeDescendant using the constructor:
```
 NodeDescendants tree = new NodeDescendants
     (mynode, NodeDescendants.SHOW_ALL);
 
```
    (which is equivalent to the NodeDescendants(Node) constructor), then the set represents all the nodes in the tree which are reachable from the node mynode by the getFirstChild and similar methods. If, however, the object was constructed with
```
 NodeDescendants tree = new NodeDescendants
     (mynode, 
     NodeDescendants.SHOW_TEXT|NodeDescendants.SHOW_CDATA_SECTION);
 
```
    then all Text and CDATA nodes would be included in the set, and only these would be returned by the iterator or visited by the visitor.
    Parameters:
    
    node - the node which is to be the root of the tree
    
    whatToShow - code indicating which node types should be included in the set
- Method Detail
  - reset
```
public void reset()
```
    Sets the object back to its initial state. This allows you to extract a second iterator either after an earlier one has finished, or before.
  - reset
```
public void reset(int whatToShow)
```
    Sets the object back to its initial state, but with a (possibly) different constraint on which nodes are included in the set.
    
    Parameters:
    
    whatToShow - code indicating which node types should be included in the set. See NodeDescendants(Node,int)
  - visitTree
```
public java.lang.Object visitTree(NodeDescendants.Visitor v)
```
    Visits each of the nodes in the tree. This method iterates through all the descendants of the given node, starting with that node, and presents each of them to the given NodeVisitor. If that object's visitNode method returns non-null, then the traversal is stopped and the returned object immediately returned as the value of this method. If the visitNode method always returns null and so the traversal completes, then the method returns null also.
    
    Parameters:
    
    v - a visitor which has each node presented to it in turn
  - iterator
```
public java.util.Iterator<org.w3c.dom.Node> iterator()
```
    Obtains an iterator which iterates over the nodes in the set of descendants. The traversal happens in depth-first order.
    
    Returns:
    
    an iterator which returns in turn the given node, then all of its descendants.

Class NodeDescendants

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SHOW_ALL

SHOW_ELEMENT

SHOW_ATTRIBUTE

SHOW_TEXT

SHOW_CDATA_SECTION

SHOW_ENTITY_REFERENCE

SHOW_ENTITY

SHOW_PROCESSING_INSTRUCTION

SHOW_COMMENT

SHOW_DOCUMENT

SHOW_DOCUMENT_TYPE

SHOW_DOCUMENT_FRAGMENT

SHOW_NOTATION

Constructor Detail

NodeDescendants

NodeDescendants

Method Detail

reset

reset

visitTree

iterator