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 471381 2006-11-05 08:56:58Z wglass $

Author:

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

Field Summary

protected Info

uberInfo

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

children, first, id, info, invalid, last, log, 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
Object	execute(Object o, InternalContextAdapter context) gets an Object that 'is' the value of the reference
String	getRootString() Returns the 'root string', the reference key
Object	getVariableValue(Context context, String variable)
Object	init(InternalContextAdapter context, Object data)
Object	jjtAccept(ParserVisitor visitor, Object data)
String	literal() Override of the SimpleNode method literal() Returns the literal representation of the node.
boolean	render(InternalContextAdapter context, Writer writer) gets the value of the reference and outputs it to the writer.
void	setLiteral(String literal) Routine to allow the literal representation to be externally overridden.
boolean	setValue(InternalContextAdapter context, Object value) Sets the value of a complex reference (something like $foo.bar) Currently used by ASTSetReference()
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, toString

Methods inherited from class java.lang.Object

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

Field Detail

uberInfo

protected Info uberInfo

Constructor Detail

ASTReference

public ASTReference(int id)

Parameters:

id -

ASTReference

public ASTReference(Parser p,
                    int id)

Parameters:

p -

id -

Method Detail

jjtAccept

public Object jjtAccept(ParserVisitor visitor,
                        Object data)

Specified by:

jjtAccept in interface Node

Overrides:

jjtAccept in class SimpleNode

Returns:

The Node execution result object.

See Also:

SimpleNode.jjtAccept(org.apache.velocity.runtime.parser.ParserVisitor, java.lang.Object)

init

public Object init(InternalContextAdapter context,
                   Object data)
            throws TemplateInitException

Specified by:

init in interface Node

Overrides:

init in class SimpleNode

Returns:

The init result.

Throws:

TemplateInitException

See Also:

SimpleNode.init(org.apache.velocity.context.InternalContextAdapter, java.lang.Object)

getRootString

public String getRootString()

Returns the 'root string', the reference key

Returns:

the root string.

execute

public Object execute(Object o,
                      InternalContextAdapter context)
               throws MethodInvocationException

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

Specified by:

execute in interface Node

Overrides:

execute in class SimpleNode

Parameters:

o - unused Object parameter

context - context used to generate value

Returns:

The execution result.

Throws:

MethodInvocationException

See Also:

Node.execute(java.lang.Object, org.apache.velocity.context.InternalContextAdapter)

render

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

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

Specified by:

render in interface Node

Overrides:

render in class SimpleNode

Parameters:

context - context of data to use in getting value

writer - writer to render to

Returns:

True if rendering was successful.

Throws:

IOException

MethodInvocationException

See Also:

Node.render(org.apache.velocity.context.InternalContextAdapter, java.io.Writer)

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

Specified by:

evaluate in interface Node

Overrides:

evaluate in class SimpleNode

Parameters:

context - context to compute value with

Returns:

True if evaluation was ok.

Throws:

MethodInvocationException

See Also:

Node.evaluate(org.apache.velocity.context.InternalContextAdapter)

value

public Object value(InternalContextAdapter context)
             throws MethodInvocationException

Specified by:

value in interface Node

Overrides:

value in class SimpleNode

Returns:

The node value.

Throws:

MethodInvocationException

See Also:

SimpleNode.value(org.apache.velocity.context.InternalContextAdapter)

setValue

public boolean setValue(InternalContextAdapter context,
                        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

Throws:

MethodInvocationException

See Also:

ASTSetDirective

getVariableValue

public Object getVariableValue(Context context,
                               String variable)
                        throws MethodInvocationException

Parameters:

context -

variable -

Returns:

The evaluated value of the variable.

Throws:

MethodInvocationException

setLiteral

public void setLiteral(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 String literal()

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

Specified by:

literal in interface Node

Overrides:

literal in class SimpleNode

Returns:

A literal string.

See Also:

Node.literal()