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:

java.lang.Cloneable, 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:

$Id$

Field Summary

Fields

Modifier and Type	Field	Description
private java.lang.String	alternateNullStringKey
private ASTExpression	astAlternateValue	non null Indicates that an alternate value has been provided
private ASTIndex	astIndex	non null Indicates if we are setting an index reference e.g, $foo[2], which basically means that the last syntax of the reference are brackets.
private boolean	checkEmpty
private boolean	computableReference
private boolean	escaped
private java.lang.String	escPrefix
private static int	FORMAL_REFERENCE
private java.lang.String	identifier
private boolean	logOnNull
private boolean	lookupAlternateLiteral
private java.lang.String	morePrefix
private static int	NORMAL_REFERENCE
private java.lang.String	nullString
private int	numChildren
private static int	QUIET_REFERENCE
private int	referenceType
private java.lang.String	rootString
private static int	RUNT
boolean	strictEscape	Indicates if we are using modified escape behavior in strict mode.
boolean	strictRef	Indicates if we are running in strict reference mode.
protected Info	uberInfo
private boolean	warnInvalidNullReferences	Whether to trigger an event for invalid null references, that is when a value is present in the context or parent object but is null
private boolean	warnInvalidQuietReferences	Whether to trigger an event for invalid quiet references
private boolean	warnInvalidTestedReferences	Whether to trigger an event for invalid tested references - as in #if($foo)

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

children, column, first, firstImage, id, info, invalid, last, lastImage, line, literal, log, parent, parser, rsvc, state, template

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
java.lang.Object	execute(java.lang.Object o, InternalContextAdapter context)	gets an Object that 'is' the value of the reference
private java.lang.String	getNullString(InternalContextAdapter context)	This method helps to implement the "render literal if null" functionality.
private java.lang.String	getRoot()
java.lang.String	getRootString()	Returns the 'root string', the reference key
java.lang.Object	getRootVariableValue(InternalContextAdapter context)
java.lang.Object	init(InternalContextAdapter context, java.lang.Object data)
java.lang.Object	jjtAccept(StandardParserVisitor visitor, java.lang.Object data)
static java.lang.String	printClass(java.lang.Class<?> clazz)	Utility class to handle nulls when printing a class type
boolean	render(InternalContextAdapter context, java.io.Writer writer)	gets the value of the reference and outputs it to the writer.
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, cleanupParserAndTokens, clone, clone, dump, dump, dump, getColumn, getFirstToken, getFirstTokenImage, getInfo, getLastToken, getLastTokenImage, getLine, getLocation, getParser, getRuntimeServices, getTemplate, getTemplateName, getType, isInvalid, jjtAddChild, jjtClose, jjtGetChild, jjtGetNumChildren, jjtGetParent, jjtOpen, jjtSetParent, literal, saveTokenImages, setFirstToken, setInfo, setInvalid, toString, toString

Methods inherited from class java.lang.Object

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

alternateNullStringKey

private java.lang.String alternateNullStringKey

rootString

private java.lang.String rootString

escaped

private boolean escaped

computableReference

private boolean computableReference

logOnNull

private boolean logOnNull

lookupAlternateLiteral

private boolean lookupAlternateLiteral

escPrefix

private java.lang.String escPrefix

morePrefix

private java.lang.String morePrefix

identifier

private java.lang.String identifier

checkEmpty

private boolean checkEmpty

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.

astAlternateValue

private ASTExpression astAlternateValue

non null Indicates that an alternate value has been provided

strictEscape

public boolean strictEscape

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

numChildren

private int numChildren

warnInvalidQuietReferences

private boolean warnInvalidQuietReferences

Whether to trigger an event for invalid quiet references

Since:

2.2

warnInvalidNullReferences

private boolean warnInvalidNullReferences

Whether to trigger an event for invalid null references, that is when a value is present in the context or parent object but is null

Since:

2.2

warnInvalidTestedReferences

private boolean warnInvalidTestedReferences

Whether to trigger an event for invalid tested references - as in #if($foo)

Since:

2.2

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 java.lang.Object jjtAccept(StandardParserVisitor visitor,
                                  java.lang.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.StandardParserVisitor, java.lang.Object)

init

public java.lang.Object init(InternalContextAdapter context,
                             java.lang.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 java.lang.String getRootString()

Returns the 'root string', the reference key

Returns:

the root string.

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 - Object parameter, unused per se, but non-null by convention inside an #if/#elseif evaluation

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,
                      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

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:

java.io.IOException

MethodInvocationException

See Also:

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

getNullString

private java.lang.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 java.lang.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 java.lang.String printClass(java.lang.Class<?> clazz)

Utility class to handle nulls when printing a class type

Parameters:

clazz -

Returns:

class name, or the string "null"

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

Throws:

MethodInvocationException

See Also:

ASTSetDirective

getRoot

private java.lang.String getRoot()

getRootVariableValue

public java.lang.Object getRootVariableValue(InternalContextAdapter context)

Parameters:

context -

Returns:

The evaluated value of the variable.

Throws:

MethodInvocationException