mondrian.calc.impl
Class MemberValueCalc

java.lang.Object
  mondrian.calc.impl.AbstractCalc
      mondrian.calc.impl.GenericCalc
          mondrian.calc.impl.MemberValueCalc

All Implemented Interfaces:

BooleanCalc, Calc, DateTimeCalc, DimensionCalc, DoubleCalc, HierarchyCalc, IntegerCalc, LevelCalc, MemberCalc, StringCalc, TupleCalc, VoidCalc

public class MemberValueCalc
extends GenericCalc

Expression which evaluates a few member expressions, sets the dimensional context to the result of those expressions, then yields the value of the current measure in the current dimensional context.

The evaluator's context is preserved.

Note that a MemberValueCalc with 0 member expressions is equivalent to a ValueCalc; see also TupleValueCalc.

Since:

Sep 27, 2005

Author:

jhyde

Field Summary

Fields inherited from class mondrian.calc.impl.AbstractCalc

exp, type

Constructor Summary

MemberValueCalc(Exp exp, MemberCalc memberCalc, boolean nullCheck)
Creates a MemberArrayValueCalc.

Method Summary

static GenericCalc	create(Exp exp, MemberCalc[] memberCalcs, boolean nullCheck) Creates a ValueCalc, MemberValueCalc or MemberArrayValueCalc.
boolean	dependsOn(Hierarchy hierarchy) Returns whether this expression depends upon a given hierarchy.
Object	evaluate(Evaluator evaluator) Evaluates this expression.
Calc[]	getCalcs() Returns this expression's child expressions.

Methods inherited from class mondrian.calc.impl.GenericCalc

evaluateBoolean, evaluateDateTime, evaluateDimension, evaluateDouble, evaluateHierarchy, evaluateInteger, evaluateLevel, evaluateMember, evaluateString, evaluateTuple, evaluateVoid, numberToDouble

Methods inherited from class mondrian.calc.impl.AbstractCalc

accept, anyDepends, anyDependsButFirst, butDepends, collectArguments, getArguments, getName, getResultStyle, getType, isWrapperFor, simplifyEvaluator, unwrap

Methods inherited from class java.lang.Object

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

Methods inherited from interface mondrian.calc.Calc

accept, getResultStyle, getType, isWrapperFor, unwrap

Constructor Detail

MemberValueCalc

public MemberValueCalc(Exp exp,
                       MemberCalc memberCalc,
                       boolean nullCheck)

Creates a MemberArrayValueCalc.

Clients outside this package should use the create(mondrian.olap.Exp, mondrian.calc.MemberCalc[], boolean) factory method.

Parameters:

exp - Expression

memberCalc - Compiled expression

nullCheck - Whether to check for null values due to non-joining dimensions in a virtual cube

Method Detail

create

public static GenericCalc create(Exp exp,
                                 MemberCalc[] memberCalcs,
                                 boolean nullCheck)

Creates a ValueCalc, MemberValueCalc or MemberArrayValueCalc.

Parameters:

exp - Expression

memberCalcs - Array of members to evaluate

nullCheck - Whether to check for null values due to non-joining dimensions in a virtual cube

Returns:

Compiled expression to evaluate each member expression, set evaluator context to each resulting member, then evaluate the current context

evaluate

public Object evaluate(Evaluator evaluator)

Description copied from interface: Calc

Evaluates this expression.

Parameters:

evaluator - Provides dimensional context in which to evaluate this expression

Returns:

Result of expression evaluation

getCalcs

public Calc[] getCalcs()

Description copied from class: AbstractCalc

Returns this expression's child expressions.

Overrides:

getCalcs in class AbstractCalc

dependsOn

public boolean dependsOn(Hierarchy hierarchy)

Description copied from interface: Calc

Returns whether this expression depends upon a given hierarchy.

If it does not depend on the hierarchy, then re-evaluating the expression with a different member of this context must produce the same answer.

Some examples:

• The expression

  [Measures].[Unit Sales]

  depends on all dimensions except [Measures].
• The boolean expression

  ([Measures].[Unit Sales], [Time].[1997]) > 1000

  depends on all hierarchies except [Measures] and [Time].
• The list expression

  Filter([Store].[USA].Children, [Measures].[Unit Sales] < 50)

  depends upon all hierarchies except [Store] and [Measures]. How so? Normally the scalar expression would depend upon all hierarchies except [Measures], but the Filter function sets the [Store] context before evaluating the scalar expression, so it is not inherited from the surrounding context.

Specified by:

dependsOn in interface Calc

Overrides:

dependsOn in class AbstractCalc

Parameters:

hierarchy - Hierarchy

Returns:

Whether this expression's result depends upon the current member of the hierarchy