org.apache.velocity.runtime.parser.node
Class ASTReference

java.lang.Object
  |
  +--org.apache.velocity.runtime.parser.node.SimpleNode
        |
        +--org.apache.velocity.runtime.parser.node.ASTReference

All Implemented Interfaces:

Node

public class ASTReference

extends SimpleNode

This class is responsible for handling the references in VTL ($foo). Please look at the Parser.jjt file which is what controls the generation of this class.

Version:

$Id: ASTReference.java,v 1.43 2002/02/23 11:00:40 geirm Exp $

Author:

Jason van Zyl, Geir Magnusson Jr., Christoph Reck,

Field Summary

private boolean	computableReference
private boolean	escaped
private java.lang.String	escPrefix
private static int	FORMAL_REFERENCE
private java.lang.String	identifier
private java.lang.String	literal
private java.lang.String	morePrefix
private static int	NORMAL_REFERENCE
private java.lang.String	nullString
private int	numChildren
private static int	QUIET_REFERENCE
private int	referenceType
private java.lang.String	rootString
private static int	RUNT

Fields inherited from class org.apache.velocity.runtime.parser.node.SimpleNode

children, first, id, info, invalid, last, parent, parser, rsvc, state

Constructor Summary

ASTReference(int id)

ASTReference(Parser p, int id)

Method Summary

boolean	evaluate(InternalContextAdapter context) Computes boolean value of this reference Returns the actual value of reference return type boolean, and 'true' if value is not null
java.lang.Object	execute(java.lang.Object o, InternalContextAdapter context) gets an Object that 'is' the value of the reference
private java.lang.String	getRoot()
java.lang.String	getRootString() Returns the 'root string', the reference key
java.lang.Object	getVariableValue(Context context, java.lang.String variable)
java.lang.Object	init(InternalContextAdapter context, java.lang.Object data)
java.lang.Object	jjtAccept(ParserVisitor visitor, java.lang.Object data) Accept the visitor.
java.lang.String	literal() Override of the SimpleNode method literal() Returns the literal representation of the node.
boolean	render(InternalContextAdapter context, java.io.Writer writer) gets the value of the reference and outputs it to the writer.
void	setLiteral(java.lang.String literal) Routine to allow the literal representation to be externally overridden.
boolean	setValue(InternalContextAdapter context, java.lang.Object value) Sets the value of a complex reference (something like $foo.bar) Currently used by ASTSetReference()
java.lang.Object	value(InternalContextAdapter context)

Methods inherited from class org.apache.velocity.runtime.parser.node.SimpleNode

childrenAccept, dump, getColumn, getFirstToken, getInfo, getLastToken, getLine, getType, isInvalid, jjtAddChild, jjtClose, jjtGetChild, jjtGetNumChildren, jjtGetParent, jjtOpen, jjtSetParent, setFirstToken, setInfo, setInvalid, toString

Methods inherited from class java.lang.Object

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

Field Detail

NORMAL_REFERENCE

private static final int NORMAL_REFERENCE

FORMAL_REFERENCE

private static final int FORMAL_REFERENCE

QUIET_REFERENCE

private static final int QUIET_REFERENCE

RUNT

private static final int RUNT

referenceType

private int referenceType

nullString

private java.lang.String nullString

rootString

private java.lang.String rootString

escaped

private boolean escaped

computableReference

private boolean computableReference

escPrefix

private java.lang.String escPrefix

morePrefix

private java.lang.String morePrefix

identifier

private java.lang.String identifier

literal

private java.lang.String literal

numChildren

private int numChildren

Constructor Detail

ASTReference

public ASTReference(int id)

ASTReference

public ASTReference(Parser p,
                    int id)

Method Detail

jjtAccept

public java.lang.Object jjtAccept(ParserVisitor visitor,
                                  java.lang.Object data)

Accept the visitor.

Overrides:

jjtAccept in class SimpleNode

init

public java.lang.Object init(InternalContextAdapter context,
                             java.lang.Object data)
                      throws java.lang.Exception

Overrides:

init in class SimpleNode

getRootString

public java.lang.String getRootString()

Returns the 'root string', the reference key

execute

public java.lang.Object execute(java.lang.Object o,
                                InternalContextAdapter context)
                         throws MethodInvocationException

gets an Object that 'is' the value of the reference

Overrides:

execute in class SimpleNode

Parameters:

o - unused Object parameter

context - context used to generate value

render

public boolean render(InternalContextAdapter context,
                      java.io.Writer writer)
               throws java.io.IOException,
                      MethodInvocationException

gets the value of the reference and outputs it to the writer.

Overrides:

render in class SimpleNode

Parameters:

context - context of data to use in getting value

writer - writer to render to

evaluate

public boolean evaluate(InternalContextAdapter context)
                 throws MethodInvocationException

Computes boolean value of this reference Returns the actual value of reference return type boolean, and 'true' if value is not null

Overrides:

evaluate in class SimpleNode

Parameters:

context - context to compute value with

value

public java.lang.Object value(InternalContextAdapter context)
                       throws MethodInvocationException

Overrides:

value in class SimpleNode

setValue

public boolean setValue(InternalContextAdapter context,
                        java.lang.Object value)
                 throws MethodInvocationException

Sets the value of a complex reference (something like $foo.bar) Currently used by ASTSetReference()

Parameters:

context - context object containing this reference

value - Object to set as value

Returns:

true if successful, false otherwise

See Also:

ASTSetDirective

getRoot

private java.lang.String getRoot()

getVariableValue

public java.lang.Object getVariableValue(Context context,
                                         java.lang.String variable)

setLiteral

public void setLiteral(java.lang.String literal)

Routine to allow the literal representation to be externally overridden. Used now in the VM system to override a reference in a VM tree with the literal of the calling arg to make it work nicely when calling arg is null. It seems a bit much, but does keep things consistant. Note, you can only set the literal once...

Parameters:

literal - String to render to when null

literal

public java.lang.String literal()

Override of the SimpleNode method literal() Returns the literal representation of the node. Should be something like $.

Overrides:

literal in class SimpleNode