com.werken.xpath
Class ContextSupport

java.lang.Object
  extended by 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)


Copyright ? 2000 bob mcwhirter and The Werken & Sons Company. All Rights Reserved.