Package 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, Renderable

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 832302 2009-11-03 05:32:31Z wglass $

Field Summary

Fields

Modifier and Type	Field	Description
private ASTIndex	astIndex	non null Indicates if we are setting an index reference e.g, $foo[2], which basically means that the last syntax of the reference are brackets.
private boolean	computableReference
private boolean	escaped
private String	escPrefix
private static final int	FORMAL_REFERENCE
private String	identifier
private String	literal
private boolean	logOnNull
private String	morePrefix
private static final int	NORMAL_REFERENCE
private String	nullString
private int	numChildren
private static final int	QUIET_REFERENCE
private int	referenceType
private String	rootString
private static final int	RUNT
boolean	strictEscape	Indicates if we are using modified escape behavior in strict mode.
boolean	strictRef	Indicates if we are running in strict reference mode.
boolean	toStringNullCheck	Indicates if toString() should be called during condition evaluation just to ensure it does not return null.
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, templateName

Constructor Summary

Constructors

Constructor	Description
ASTReference(int id)
ASTReference(Parser p, int id)

Method Summary

Modifier and Type	Method	Description
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	getDollarBang()
private String	getNullString(InternalContextAdapter context)	This method helps to implement the "render literal if null" functionality.
private String	getRoot()
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)
static String	printClass(Class clazz)	Utility class to handle nulls when printing a class type
boolean	render(InternalContextAdapter context, Writer writer)	gets the value of the reference and outputs it to the writer.
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, getLocation, getRuntimeServices, getTemplateName, getType, isInvalid, jjtAddChild, jjtClose, jjtGetChild, jjtGetNumChildren, jjtGetParent, jjtOpen, jjtSetParent, literal, setFirstToken, setInfo, setInvalid, toString, toString

Methods inherited from class java.lang.Object

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

Field Details

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 String nullString

rootString

private String rootString

escaped

private boolean escaped

computableReference

private boolean computableReference

logOnNull

private boolean logOnNull

escPrefix

private String escPrefix

morePrefix

private String morePrefix

identifier

private String identifier

literal

private String literal

strictRef

public boolean strictRef

Indicates if we are running in strict reference mode.

astIndex

private ASTIndex astIndex

non null Indicates if we are setting an index reference e.g, $foo[2], which basically means that the last syntax of the reference are brackets.

strictEscape

public boolean strictEscape

Indicates if we are using modified escape behavior in strict mode. mainly we allow \$abc -> to render as $abc

toStringNullCheck

public boolean toStringNullCheck

Indicates if toString() should be called during condition evaluation just to ensure it does not return null. Check is unnecessary if all toString() implementations are known to have non-null return values. Disabling the check will give a performance improval since toString() may be a complex operation on large objects.

numChildren

private int numChildren

uberInfo

protected Info uberInfo

Constructor Details

ASTReference

public ASTReference(int id)

Parameters:

id -

ASTReference

public ASTReference(Parser p,
 int id)

Parameters:

p -

id -

Method Details

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.node.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

Specified by:

render in interface Renderable

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)

getNullString

private String getNullString(InternalContextAdapter context)

This method helps to implement the "render literal if null" functionality. VelocimacroProxy saves references to macro arguments (AST nodes) so that if we have a macro #foobar($a $b) then there is key "$a.literal" which points to the literal presentation of the argument provided to variable $a. If the value of $a is null, we render the string that was provided as the argument.

Parameters:

context -

Returns:

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)

printClass

public static String printClass(Class clazz)

Utility class to handle nulls when printing a class type

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

getRoot

private String getRoot()

getVariableValue

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

Parameters:

context -

variable -

Returns:

The evaluated value of the variable.

Throws:

MethodInvocationException

getDollarBang

public String getDollarBang()