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

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.CustomOperator

All Implemented Interfaces:

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

public class CustomOperator
extends AbstractExpression

The custom operator provides an extension mechanism for defining operations not currently supported by this specification.

use the class attr to point to A java class (fully qualified) that implements Expression (and possibly extends AbstractExpression). If you do extend AbstractExpression, set the CLASS_TAG to "customOperator", or override relevant methods required for validation that might call getType() to stop unsupportedExpression exceptions at runtime.

Author:

Jonathon Hare

See Also:

Serialized Form

Field Summary

static java.lang.String	ATTR_CLASS_NAME Name of the class attribute in xml schema.
static java.lang.String	ATTR_DEFINITION_NAME Name of the definition 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

CustomOperator(ExpressionParent parent)
Constructs expression.

Method Summary

protected Value	evaluateSelf(int depth) Evaluates this expression.
java.lang.String	getClassAttr() Gets value of class attribute.
java.lang.String	getClassTag() Gets QTI class name of this node.
java.lang.String	getDefinition() Gets value of definition attribute.
BaseType[]	getProducedBaseTypes() Gets list of all possible produced baseTypes after evaluation (possible baseTypes of evaluated result).
Cardinality[]	getProducedCardinalities() Gets list of all possible produced cardinalities after evaluation (possible cardinalities of evaluated result).
BaseType[]	getRequiredBaseTypes(int index) Gets list of all acceptable baseTypes which can child expression at given position produce.
Cardinality[]	getRequiredCardinalities(int index) Gets list of all acceptable cardinalities which can child expression at given position produce.
protected void	loadAttributes(org.w3c.dom.Node node) Loads all attributes from given xml source.
void	setClassAttr(java.lang.String name) Sets value of class attribute.
void	setDefinition(java.lang.String name) Sets value of definition attribute.
ValidationResult	validate() Validates this object.

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

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

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, readChild, readChildren, setParent, setSourceFile, setSourceNode, setSourceString, setSourceUrl, toXmlString, toXmlString, validateAttributes, 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, 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

ATTR_CLASS_NAME

public static final java.lang.String ATTR_CLASS_NAME

Name of the class attribute in xml schema.

See Also:

Constant Field Values

ATTR_DEFINITION_NAME

public static final java.lang.String ATTR_DEFINITION_NAME

Name of the definition attribute in xml schema.

See Also:

Constant Field Values

Constructor Detail

CustomOperator

public CustomOperator(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

getClassAttr

public java.lang.String getClassAttr()

Gets value of class attribute.

Returns:

value of class attribute

setClassAttr

public void setClassAttr(java.lang.String name)

Sets value of class attribute.

getDefinition

public java.lang.String getDefinition()

Gets value of definition attribute.

Returns:

value of definition attribute

setDefinition

public void setDefinition(java.lang.String name)

Sets value of definition attribute.

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

getProducedCardinalities

public Cardinality[] getProducedCardinalities()

Description copied from interface: Expression

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

Static example is expression or. Expression or can produce only single cardinality and it cannot change.

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

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

Specified by:

getProducedCardinalities in interface Expression

Overrides:

getProducedCardinalities in class AbstractExpression

Returns:

list of all possible produced cardinalities after evaluation

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

getRequiredCardinalities

public Cardinality[] getRequiredCardinalities(int index)

Description copied from interface: ExpressionParent

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

For example delete expression returns single cardinality for index 0 and list of multiple and ordered cardinality for index 1.

Result of this method can change in time.

Static example is expression or. Expression or accepts only single cardinality for any index.

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

Specified by:

getRequiredCardinalities in interface ExpressionParent

Overrides:

getRequiredCardinalities in class AbstractExpression

Parameters:

index - position of child expression in this parent

Returns:

list of all possible cardinalities which can child expression at given position produce

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

validate

public ValidationResult validate()

Description copied from interface: Validatable

Validates this object.

Specified by:

validate in interface Validatable

Overrides:

validate in class AbstractExpression

Returns:

validation result

loadAttributes

protected void loadAttributes(org.w3c.dom.Node node)

Description copied from class: AbstractNode

Loads all attributes from given xml source.

Overrides:

loadAttributes in class AbstractNode

Parameters:

node - xml source