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

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.FieldValue

All Implemented Interfaces:

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

public class FieldValue
extends AbstractExpression

The field-value operator takes A sub-expression with A record container value. The result is the value of the field with the specified fieldIdentifier. If there is no field with that identifier then the result of the operator is NULL.

Author:

Jiri Kajaba

See Also:

Cardinality, BaseType, Serialized Form

Field Summary

static java.lang.String	ATTR_IDENTIFIER_NAME Name of identifier attribute in xml schema.
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

FieldValue(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.
java.lang.String	getIdentifier() Gets value of identifier attribute.
BaseType[]	getProducedBaseTypes() Gets list of all possible produced baseTypes after evaluation (possible baseTypes of evaluated result).
java.lang.String	getSimpleName() Gets simple name of this node.
void	setIdentifier(java.lang.String identifier) Sets new value of identifier attribute.
protected ValidationResult	validateAttributes() Validates attributes of this node.

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

evaluate, getBaseType, getCardinality, getChildren, getFirstChild, getParent, getParentRequiredBaseTypes, getParentRequiredCardinalities, getProducedCardinalities, getProducedNumericalBaseTypes, getRequiredBaseTypes, 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, getSourceFile, getSourceNode, getSourceString, getSourceUrl, hasChildNodes, load, load, load, load, loadAttributes, readChild, readChildren, setParent, setSourceFile, setSourceNode, setSourceString, setSourceUrl, toXmlString, toXmlString, validateChildren

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, 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

ATTR_IDENTIFIER_NAME

public static final java.lang.String ATTR_IDENTIFIER_NAME

Name of identifier attribute in xml schema.

See Also:

Constant Field Values

Constructor Detail

FieldValue

public FieldValue(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

getSimpleName

public java.lang.String getSimpleName()

Description copied from interface: XmlNode

Gets simple name of this node. Simple name contains QTI class name and some additional information to help identify node (if these informations are available).

Simple name is not so important like QTI class name. It servers mostly for displaying informations and in messages.

For example: simple name can be assessmentTest:Test (QTI class name (assessmentTest) + identifier (Test)).

Specified by:

getSimpleName in interface XmlNode

Overrides:

getSimpleName in class AbstractNode

Returns:

simple name of this node

See Also:

XmlNode.getFullName()

getIdentifier

public java.lang.String getIdentifier()

Gets value of identifier attribute.

Returns:

value of identifier attribute

See Also:

setIdentifier(java.lang.String)

setIdentifier

public void setIdentifier(java.lang.String identifier)

Sets new value of identifier attribute.

Parameters:

identifier - new value of identifier attribute

See Also:

getIdentifier()

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

validateAttributes

protected ValidationResult validateAttributes()

Description copied from class: AbstractNode

Validates attributes of this node.

Overrides:

validateAttributes 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