com.xmlmind.xml.xpath

Class DelegateExprContext

java.lang.Object

com.xmlmind.xml.xpath.DelegateExprContext

All Implemented Interfaces:

ExprContext

public abstract class DelegateExprContext
extends Object
implements ExprContext

An expression context which delegates all its operations to another ExprContext.

Field Summary

Fields

Modifier and Type	Field and Description
protected ExprContext	origContext

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	DelegateExprContext(ExprContext context)

Method Summary

Modifier and Type	Method and Description
XNode	findElementWithId(XNode node, String id) Used to implement the id() function in an expression.
XNode	getCurrent(XNode contextNode) Used to implement the current() function.
NodeIterator	getDocument(String uriRef, URL baseURL) Used to implement the document() function.
NodeIterator	getKeyedNodes(Name keyName, String keyValue, XNode node) Used to implement the key() function.
int	getLastPosition() Returns a number equal to the context position from this expression evaluation context.
int	getPosition() Returns a number equal to the context size from this expression evaluation context.
Variant	getVariableValue(Name name, XNode node) Returns the value of variable with specified name if any; null otherwise
boolean	isElementWithId(XNode node, String id) Used to implement the id() function in a pattern.

Methods inherited from class java.lang.Object

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

Field Detail

origContext

protected ExprContext origContext

Constructor Detail

DelegateExprContext

protected DelegateExprContext(ExprContext context)

Method Detail

getPosition

public int getPosition()
                throws EvalException

Description copied from interface: ExprContext

Returns a number equal to the context size from this expression evaluation context.

Specified by:

getPosition in interface ExprContext

Throws:

EvalException

getLastPosition

public int getLastPosition()
                    throws EvalException

Description copied from interface: ExprContext

Returns a number equal to the context position from this expression evaluation context.

Specified by:

getLastPosition in interface ExprContext

Throws:

EvalException

getVariableValue

public Variant getVariableValue(Name name,
                                XNode node)
                         throws EvalException

Description copied from interface: ExprContext

Returns the value of variable with specified name if any; null otherwise

Specified by:

getVariableValue in interface ExprContext

node - the context node. Generally not useful.

Throws:

EvalException

getCurrent

public XNode getCurrent(XNode contextNode)

Description copied from interface: ExprContext

Used to implement the current() function.

In practice, the single only useful implementation of this method is in private class WithCurrentExpr.

Specified by:

getCurrent in interface ExprContext

Parameters:

contextNode - the context node. For an outermost expression (an expression not occurring within another expression), the current node is always the same as the context node.

Returns:

the current node

findElementWithId

public XNode findElementWithId(XNode node,
                               String id)
                        throws EvalException

Description copied from interface: ExprContext

Used to implement the id() function in an expression.

Specified by:

findElementWithId in interface ExprContext

Parameters:

node - used to specify the document

id - searched ID value

Returns:

element in document specified by node having specified ID if any; null otherwise

Throws:

EvalException - if a problem occurs during the search

isElementWithId

public boolean isElementWithId(XNode node,
                               String id)
                        throws EvalException

Description copied from interface: ExprContext

Used to implement the id() function in a pattern.

Specified by:

isElementWithId in interface ExprContext

Parameters:

node - node possibly having an ID attribute

id - ID value to be matched against the possible ID attribute of node

Returns:

true if specified node has an ID attribute having specified value; false otherwise

Throws:

EvalException - if a problem occurs during the match

getDocument

public NodeIterator getDocument(String uriRef,
                                URL baseURL)
                         throws EvalException

Description copied from interface: ExprContext

Used to implement the document() function.

Specified by:

getDocument in interface ExprContext

Parameters:

uriRef - specifies nodes (using a fragment) in a document

baseURL - URL possibly used to resolve relative URL in uriRef; may be null

Returns:

nodes specified by uriRef

Throws:

EvalException - if a problem occurs during the operation

getKeyedNodes

public NodeIterator getKeyedNodes(Name keyName,
                                  String keyValue,
                                  XNode node)
                           throws EvalException

Description copied from interface: ExprContext

Used to implement the key() function.

Specified by:

getKeyedNodes in interface ExprContext

Parameters:

keyName - name of the key

keyValue - searched value

node - the context node.

Returns:

nodes belonging to the same document as node having specified key with specified value.

The returned nodes don't need to be sorted by document order.

Throws:

EvalException - if a problem occurs during the operation