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com.bea.p13n.expression.operator
Class If

java.lang.Object
com.bea.p13n.expression.internal.ComplexExpressionImpl
com.bea.p13n.expression.operator.Operator
com.bea.p13n.expression.operator.If

All Implemented Interfaces

Expression, com.bea.p13n.expression.ExpressionEvents, Serializable, Cloneable

public final class If

extends Operator

Implementation of the If operator. The If operator consists of three parts, the condition, the true action and the false action. If the condition evaluates to true the true action is evaluated otherwise the false condition is evaluated.
Input 1: A Boolean object or Expression returning a Boolean object.
Input 2: An Expression
Input 3 (optional): An Expression.
Returns: The result of evaluating the true or false expression.

See Also

Serialized Form

Field Summary

Fields inherited from interface com.bea.p13n.expression.ExpressionEvents

EVENT_ADD_SUBEXPRESSION, EVENT_CLEAR_CACHE, EVENT_INTERNAL_MAX, EVENT_REMOVE_SUBEXPRESSION, EVENT_SET_CACHE_ENABLED, EVENT_SET_CACHED_VALUE, EVENT_SET_PARENT, EVENT_SET_SOURCE, EVENT_SET_SUBEXPRESSION, EVENT_SET_USER_DATA

Constructor Summary

If()
Constructs an empty operator and operands can be added later by calling addSubExpression() on this.

If(Object logical, Object trueEx, Object falseEx)
Constructs this operator for the given operands.

Method Summary

Object	getFalseExpression()
Object	getLogicalExpression()
Class[]	getParameterSignature() Returns the parameter signature for this Expression.
Object	getTrueExpression()

Methods inherited from class com.bea.p13n.expression.operator.Operator

leftHandSide, operand, rightHandSide

Methods inherited from class com.bea.p13n.expression.internal.ComplexExpressionImpl

addListener, addSubExpression, clearCache, clone, createProxyExpression, equals, getCachedValue, getParent, getSource, getSubExpression, getSubExpressionCount, getUserData, hashCode, isCached, isCacheEnabled, isEqualitySubExpression, notifyListeners, removeAllSubExpressions, removeListener, removeSubExpression, removeSubExpression, setCachedValue, setCacheEnabled, setParent, setSource, setSubExpression, setUserData, toString, write

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

If

public If()

Constructs an empty operator and operands can be added later by calling addSubExpression() on this.

If

public If(Object logical,
          Object trueEx,
          Object falseEx)

Constructs this operator for the given operands.

Parameters

logical - A Boolean object or expression returning a Boolean object.

trueEx - An expression that is executed if logical returns Boolean true object.

falseEx - An expression that is executed if logical returns Boolean false object.

Method Detail

getLogicalExpression

public Object getLogicalExpression()

getTrueExpression

public Object getTrueExpression()

getFalseExpression

public Object getFalseExpression()

getParameterSignature

public Class[] getParameterSignature()

Description copied from interface: Expression

Returns the parameter signature for this Expression. Because the sub-expressions within the Expression are typically arguments or operands, some type validation is performed by examining the class types of the sub-expressions against the Expression's parameter signature.
The tests that are performed are:
1. The number of sub-expressions must equals the number of parameter entries.
2. The class type of any sub-expression (or the result of evaluating the sub-expresssion) must equal the class type of the corresponding parameter entry.
3. Any null parameter entries are ignored and are considered optional sub-expressions.

Returns

the Class array containing the parameter signature.

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