org.qtitools.qti.node.expression.operator
Class Multiple

java.lang.Object
  org.qtitools.qti.node.AbstractNode
      org.qtitools.qti.node.AbstractObject
          org.qtitools.qti.node.expression.AbstractExpression
              org.qtitools.qti.node.expression.operator.Multiple

All Implemented Interfaces:

java.io.Serializable, Expression, ExpressionParent, XmlNode, XmlObject, Validatable

public class Multiple
extends AbstractExpression

The multiple operator takes 0 or more sub-expressions all of which must have either single or multiple cardinality. Although the sub-expressions may be of any base-type they must all be of the same base-type. The result is A container with multiple cardinality containing the values of the sub-expressions, sub-expressions with multiple cardinality have their individual values added to the result: containers cannot contain other containers.

For example, when applied to A, B and {C,D} the multiple operator results in {A,B,C,D}.

All sub-expressions with NULL values are ignored. If no sub-expressions are given (or all are NULL) then the result is NULL.

Author:

Jiri Kajaba

See Also:

Cardinality, BaseType, Serialized Form

Field Summary

static java.lang.String

CLASS_TAG Name of this class in xml schema.

Fields inherited from class org.qtitools.qti.node.expression.AbstractExpression

logger

Fields inherited from interface org.qtitools.qti.node.expression.Expression

DISPLAY_NAME

Fields inherited from interface org.qtitools.qti.node.XmlNode

INDENT, NEW_LINE, SIMPLE_NAME_INNER_SEPARATOR, SIMPLE_NAMES_SEPARATOR

Constructor Summary

Multiple(ExpressionParent parent)
Constructs expression.

Method Summary

protected Value	evaluateSelf(int depth) Evaluates this expression.
java.lang.String	getClassTag() Gets QTI class name of this node.
BaseType[]	getProducedBaseTypes() Gets list of all possible produced baseTypes after evaluation (possible baseTypes of evaluated result).
BaseType[]	getRequiredBaseTypes(int index) Gets list of all acceptable baseTypes which can child expression at given position produce.
protected ValidationResult	validateChildren() Validates children (body) of this node.

Methods inherited from class org.qtitools.qti.node.expression.AbstractExpression

evaluate, getBaseType, getCardinality, getChildren, getFirstChild, getParent, getParentRequiredBaseTypes, getParentRequiredCardinalities, getProducedCardinalities, getProducedNumericalBaseTypes, getRequiredCardinalities, getRequiredSameBaseTypes, getRequiredSameCardinalities, getSecondChild, getType, getValue, isAnyChildNull, isNull, isVariable, reset, toString, validate

Methods inherited from class org.qtitools.qti.node.AbstractObject

getParentItem, getParentResult, getParentTest, setParent

Methods inherited from class org.qtitools.qti.node.AbstractNode

attrToXmlString, bodyToXmlString, getAttributes, getFullName, getIndent, getNode, getNode, getNode, getNodeGroups, getParentRoot, getSimpleName, getSourceFile, getSourceNode, getSourceString, getSourceUrl, hasChildNodes, load, load, load, load, loadAttributes, readChild, readChildren, setParent, setSourceFile, setSourceNode, setSourceString, setSourceUrl, toXmlString, toXmlString, validateAttributes

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.qtitools.qti.node.XmlObject

getParentItem, getParentResult, getParentTest, setParent

Methods inherited from interface org.qtitools.qti.node.XmlNode

getAttributes, getFullName, getNodeGroups, getParentRoot, getSimpleName, getSourceFile, getSourceNode, getSourceString, getSourceUrl, hasChildNodes, load, load, load, load, setSourceFile, setSourceNode, setSourceString, setSourceUrl, toXmlString, toXmlString

Field Detail

CLASS_TAG

public static final java.lang.String CLASS_TAG

Name of this class in xml schema.

See Also:

Constant Field Values

Constructor Detail

Multiple

public Multiple(ExpressionParent parent)

Constructs expression.

Parameters:

parent - parent of this expression

Method Detail

getClassTag

public java.lang.String getClassTag()

Description copied from interface: XmlNode

Gets QTI class name of this node.

QTI class name has very important role during loading/saving nodes.

For example: Java class name is AssessmentTest; QTI class name is assessmentTest.

Specified by:

getClassTag in interface XmlNode

Specified by:

getClassTag in class AbstractNode

Returns:

QTI class name of this node

getRequiredBaseTypes

public BaseType[] getRequiredBaseTypes(int index)

Description copied from interface: ExpressionParent

Gets list of all acceptable baseTypes which can child expression at given position produce.

Result of this method can change in time.

Static example is expression or. Expression or accepts only boolean baseType for any index.

Dynamic example is expression match. Expression match accepts any baseType of its children. but this baseType must be same for all its children.

Specified by:

getRequiredBaseTypes in interface ExpressionParent

Overrides:

getRequiredBaseTypes in class AbstractExpression

Parameters:

index - position of child expression in this parent

Returns:

list of all acceptable baseTypes which can child expression at given position produce

getProducedBaseTypes

public BaseType[] getProducedBaseTypes()

Description copied from interface: Expression

Gets list of all possible produced baseTypes after evaluation (possible baseTypes of evaluated result). Result of this method can change in time.

Static example is expression or. Expression or can produce only boolean baseType and it cannot change.

Dynamic example is expression variable. Expression variable can produce any baseType before evaluation. After evaluation it produces baseType of its result (and it can change every evaluation call!).

Null expression, empty containers (multiple, ordered, record), or NULL values produces all baseTypes. So they are compatible with anything.

Specified by:

getProducedBaseTypes in interface Expression

Overrides:

getProducedBaseTypes in class AbstractExpression

Returns:

list of all possible produced baseTypes after evaluation

validateChildren

protected ValidationResult validateChildren()

Description copied from class: AbstractNode

Validates children (body) of this node.

Overrides:

validateChildren in class AbstractNode

Returns:

result of validation

evaluateSelf

protected Value evaluateSelf(int depth)

Description copied from class: AbstractExpression

Evaluates this expression. All children must be already evaluated. Contains no checks.

Specified by:

evaluateSelf in class AbstractExpression

Parameters:

depth - depth of this expression in expression tree (root's depth = 0)

Returns:

result of evaluation