uk.ac.sheffield.jast.filter

Class ValueFilter

java.lang.Object

uk.ac.sheffield.jast.filter.Filter

uk.ac.sheffield.jast.filter.MaskFilter

uk.ac.sheffield.jast.filter.ValueFilter

public class ValueFilter
extends MaskFilter

ValueFilter is a simple filter selecting nodes that have a given value. A ValueFilter accepts a subset of Content nodes, whose associated value is equal to a reference value. Nodes with values are the union of the Element, Attribute, Text and Data node types; and may be restricted to a subset of these types.

ValueFilter has an accept(Content) method, which returns true, if the Content node is an acceptable type and the comparison of the node's value against the reference value succeeds. The node's value is extracted using the getText() method. Comparison succeeds if this text value is equal to the reference pattern, according to String comparison. ValueFilter is less general than RestrictFilter, which supports a variety of restrictions including equality, but is more efficient, since it does not need to convert values into other primitive types.

Version:

2.5

Author:

Anthony J H Simons

Field Summary

Fields

Modifier and Type	Field and Description
private java.lang.String	value The reference value for this ValueFilter.

Fields inherited from class uk.ac.sheffield.jast.filter.MaskFilter

mask

Fields inherited from class uk.ac.sheffield.jast.filter.Filter

ALLCONTENT, NAMENODES, PARENTNODES, PROPERTYNODES, VALUENODES, XPATHNODES, XPATHTEXT

Constructor Summary

Constructors

Constructor and Description
ValueFilter(java.lang.String value) Creates a ValueFilter that filters for nodes having the given value.
ValueFilter(java.lang.String value, int contentType) Creates a ValueFilter for nodes of the given content-type having the given value.

Method Summary

Modifier and Type	Method and Description
boolean	accept(Content node) Reports whether a given Content node is accepted by this ValueFilter.
protected ValueFilter	andNodeFilter(NodeFilter other) Creates a Filter that is the conjunction of this ValueFilter and a NodeFilter.

Methods inherited from class uk.ac.sheffield.jast.filter.MaskFilter

getMask

Methods inherited from class uk.ac.sheffield.jast.filter.Filter

and, andIndexFilter, not, or, orNodeFilter, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

value

private java.lang.String value

The reference value for this ValueFilter.

Constructor Detail

ValueFilter

public ValueFilter(java.lang.String value)

Creates a ValueFilter that filters for nodes having the given value.

Parameters:

value - the reference value to match.

ValueFilter

public ValueFilter(java.lang.String value,
                   int contentType)

Creates a ValueFilter for nodes of the given content-type having the given value.

Parameters:

value - the reference value to match.

contentType - a bit-mask specifying one or more content-types.

Method Detail

accept

public boolean accept(Content node)

Reports whether a given Content node is accepted by this ValueFilter. Used when searching through lists of Content to restrict which nodes are acceptable. A node is accepted if it has textual content, which is equal to the reference value.

Overrides:

accept in class MaskFilter

Parameters:

node - a Content node.

Returns:

true, if the node is accepted, otherwise false.

andNodeFilter

protected ValueFilter andNodeFilter(NodeFilter other)

Creates a Filter that is the conjunction of this ValueFilter and a NodeFilter. Returns a new ValueFilter accepting the same value, but combining the bit-masks of this and the other NodeFilter using bitwise-AND. This is more efficient than the general approach using an AndFilter.

Overrides:

andNodeFilter in class Filter

Parameters:

other - the other NodeFilter.

Returns:

a new Filter.