com.werken.xpath
Class ContextSupport

java.lang.Object
  com.werken.xpath.ContextSupport

public class ContextSupport
extends java.lang.Object

ContextSupport maintains information to aid in the execution of the XPath against a context node.

It separates the knowledge of functions, variables and namespace-bindings from the context node to be walked.

Author:

bob mcwhirter (bob @ werken.com)

Constructor Summary

ContextSupport()
Construct a semantically empty ContextSupport

ContextSupport(NamespaceContext nsContext, FunctionContext functionContext, VariableContext variableContext)
Construct a semantically initialized ContextSupport

Method Summary

Function	getFunction(java.lang.String name) Retrieve a named function
java.lang.Object	getVariableValue(java.lang.String name) Resolve a variable binding
void	setFunctionContext(FunctionContext functionContext) Set the FunctionContext implementation
void	setNamespaceContext(NamespaceContext nsContext) Set the NamespaceContext implementation
void	setVariableContext(VariableContext variableContext) Set the VariableContext implementation
java.lang.String	translateNamespacePrefix(java.lang.String prefix) Translate a namespace prefix into a URI

Methods inherited from class java.lang.Object

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

Constructor Detail

ContextSupport

public ContextSupport()

Construct a semantically empty ContextSupport

ContextSupport

public ContextSupport(NamespaceContext nsContext,
                      FunctionContext functionContext,
                      VariableContext variableContext)

Construct a semantically initialized ContextSupport

Parameters:

nsContext - The NamespaceContext implementation

functionContext - The FunctionContext implementation

variableContext - The VariableContext implementation

Method Detail

setNamespaceContext

public void setNamespaceContext(NamespaceContext nsContext)

Set the NamespaceContext implementation

Parameters:

nsContext - The NamespaceContext implementation

setFunctionContext

public void setFunctionContext(FunctionContext functionContext)

Set the FunctionContext implementation

Parameters:

functionContext - The FunctionContext implementation

setVariableContext

public void setVariableContext(VariableContext variableContext)

Set the VariableContext implementation

Parameters:

variableContext - The FunctionContext implementation

translateNamespacePrefix

public java.lang.String translateNamespacePrefix(java.lang.String prefix)

Translate a namespace prefix into a URI

Using the NamespaceContext implementation, translate the prefix used in a component of an XPath into its expanded namespace URI.

Parameters:

prefix - The namespace prefix

Returns:

The URI matching the prefix

See Also:

setNamespaceContext(com.werken.xpath.NamespaceContext)

getFunction

public Function getFunction(java.lang.String name)

Retrieve a named function

Retrieve the named function object, or null if no such function exists. Delegates to the FunctionContext implementation provided, if any.

Parameters:

name - The name of the function sought.

Returns:

The Function matching the specified name.

See Also:

setFunctionContext(com.werken.xpath.FunctionContext)

getVariableValue

public java.lang.Object getVariableValue(java.lang.String name)

Resolve a variable binding

Retrieve the currently bound value of the named variable, or null if no such binding exists. Delegates to the VariableContext implementation provided, if any.

Parameters:

name - The name of the variable sought.

Returns:

The currently bound value of the variable, or null.

See Also:

setVariableContext(com.werken.xpath.VariableContext)