Package com.google.auto.value.processor.escapevelocity

Class ExpressionNode

java.lang.Object

com.google.auto.value.processor.escapevelocity.Node

com.google.auto.value.processor.escapevelocity.ExpressionNode

Direct Known Subclasses:

ConstantExpressionNode, ExpressionNode.BinaryExpressionNode, ExpressionNode.NotExpressionNode, ReferenceNode

abstract class ExpressionNode
extends Node

A node in the parse tree representing an expression. Expressions appear inside directives, specifically #set, #if, #foreach, and macro calls. Expressions can also appear inside indices in references, like $x[$i].

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	ExpressionNode.BinaryExpressionNode	Represents all binary expressions.
(package private) static class	ExpressionNode.NotExpressionNode	A node in the parse tree representing an expression like !$a.

Field Summary

Fields inherited from class com.google.auto.value.processor.escapevelocity.Node

lineNumber, resourceName

Constructor Summary

Constructors

Constructor	Description
ExpressionNode(String resourceName, int lineNumber)

Method Summary

Modifier and Type	Method	Description
(package private) int	intValue(EvaluationContext context)	The integer result of evaluating this expression.
(package private) boolean	isDefinedAndTrue(EvaluationContext context)	True if this is a defined value and it evaluates to true.
(package private) boolean	isTrue(EvaluationContext context)	True if evaluating this expression yields a value that is considered true by Velocity's rules.
private static String	show(Object value)	Returns a string representing the given value, for use in error messages.

Methods inherited from class com.google.auto.value.processor.escapevelocity.Node

cons, emptyNode, evaluate, evaluationException, evaluationException

Methods inherited from class java.lang.Object

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

Constructor Details

ExpressionNode

ExpressionNode(String resourceName,
 int lineNumber)

Method Details

isTrue

boolean isTrue(EvaluationContext context)

True if evaluating this expression yields a value that is considered true by Velocity's rules. A value is false if it is null or equal to Boolean.FALSE. Every other value is true.

Note that the text at the similar link here states that empty collections and empty strings are also considered false, but that is not true.

isDefinedAndTrue

boolean isDefinedAndTrue(EvaluationContext context)

True if this is a defined value and it evaluates to true. This is the same as isTrue(com.google.auto.value.processor.escapevelocity.EvaluationContext) except that it is allowed for this to be undefined variable, in which it evaluates to false. The method is overridden for plain references so that undefined is the same as false. The reason is to support Velocity's idiom #if ($var), where it is not an error if $var is undefined.

intValue

int intValue(EvaluationContext context)

The integer result of evaluating this expression.

Throws:

EvaluationException - if evaluating the expression produces an exception, or if it yields a value that is not an integer.

show

private static String show(Object value)

Returns a string representing the given value, for use in error messages. The string includes both the value's toString() and its type.