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, toString, wait, wait, wait
 

Field Detail

NORMAL_REFERENCE

private static final int NORMAL_REFERENCE
See Also:
Constant Field Values

FORMAL_REFERENCE

private static final int FORMAL_REFERENCE
See Also:
Constant Field Values

QUIET_REFERENCE

private static final int QUIET_REFERENCE
See Also:
Constant Field Values

RUNT

private static final int RUNT
See Also:
Constant Field Values

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.

Specified by:
jjtAccept in interface Node
Overrides:
jjtAccept in class SimpleNode

init

public java.lang.Object init(InternalContextAdapter context,
                             java.lang.Object data)
                      throws java.lang.Exception
Specified by:
init in interface Node
Overrides:
init in class SimpleNode
java.lang.Exception

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

Specified by:
execute in interface Node
Overrides:
execute in class SimpleNode
Parameters:
o - unused Object parameter
context - context used to generate value
MethodInvocationException

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.

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
java.io.IOException
MethodInvocationException

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
MethodInvocationException

value

public java.lang.Object value(InternalContextAdapter context)
                       throws MethodInvocationException
Specified by:
value in interface Node
Overrides:
value in class SimpleNode
MethodInvocationException

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
MethodInvocationException
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 $.

Specified by:
literal in interface Node
Overrides:
literal in class SimpleNode


Copyright ? 2003 Apache Software Foundation. All Rights Reserved.