*** This class is subject to change. ***

com.sas.iquery.metadata.expr
Class ConstantExpression

com.sas.iquery.metadata.expr.ConstantExpression

All Implemented Interfaces:

Base, BusinessModelResourceReferencer, ModelItem, UsabilityInterface, com.sas.iquery.metadata.expr.ConstantExpressionInterface, ExpressionInterface, PropertyChangeListenee, java.beans.PropertyChangeListener, java.lang.Cloneable, java.util.EventListener

public class ConstantExpression
implements com.sas.iquery.metadata.expr.ConstantExpressionInterface

Specifies a constant value modeled as a string with an expression type. Since a ConstantExpression can contain a MissingValue, users of this class need to check if its value is a MissingValue before safely converting the value of a ConstantExpression to a number.

See Also:

isMissing()

Field Summary

static java.lang.String	EVENT_EXPRESSION_TYPE_CHANGED The event thrown when the expression type has changed values.
static java.lang.String	EVENT_VALUE_CHANGED The event thrown when the expression value has changed values.

Fields inherited from interface com.sas.iquery.metadata.business.ModelItem

EVENT_OBJECT_PROPERTY_CHANGED

Fields inherited from interface com.sas.iquery.metadata.business.Base

EVENT_OBJECT_DEFINITION_CHANGED

Constructor Summary

ConstantExpression()

ConstantExpression(java.lang.String value, int type)
Creates an ConstantExpression with the specified value and type.

Method Summary

int	getExpressionType() Return the integer form of the expression type.
java.lang.String	getValue() Return value of this constant in string form.
boolean	isMissing() Checks if this ConstantExpression's value is a SAS MissingValue
void	setExpressionType(int type) Sets the expression type with a value from class ExpressionTypes
void	setValue(java.lang.String value) Sets the value of this constant as a String object

Methods inherited from interface com.sas.iquery.metadata.business.BusinessModelResourceReferencer

getResources

Methods inherited from interface com.sas.iquery.metadata.PropertyChangeListenee

addListener, getListeners, removeListener

Methods inherited from interface com.sas.iquery.metadata.business.UsabilityInterface

getReasonsUnusable, isUsableInQuery

Field Detail

*** This field is subject to change. ***

EVENT_EXPRESSION_TYPE_CHANGED

public static final java.lang.String EVENT_EXPRESSION_TYPE_CHANGED

The event thrown when the expression type has changed values.

See Also:

Constant Field Values

*** This field is subject to change. ***

EVENT_VALUE_CHANGED

public static final java.lang.String EVENT_VALUE_CHANGED

The event thrown when the expression value has changed values.

See Also:

Constant Field Values

Constructor Detail

*** This constructor is subject to change. ***

ConstantExpression

public ConstantExpression()

*** This constructor is subject to change. ***

ConstantExpression

public ConstantExpression(java.lang.String value,
                          int type)

Creates an ConstantExpression with the specified value and type.

Parameters:

value - the value of the expression

type - the expression type with a value from class ExpressionTypes

Method Detail

*** This method is subject to change. ***

getExpressionType

public int getExpressionType()

Description copied from interface: ExpressionInterface

Return the integer form of the expression type.

Specified by:

getExpressionType in interface ExpressionInterface

Returns:

an expression type from the values in class ExpressionTypes

*** This method is subject to change. ***

setExpressionType

public void setExpressionType(int type)

Sets the expression type with a value from class ExpressionTypes

Specified by:

setExpressionType in interface com.sas.iquery.metadata.expr.ConstantExpressionInterface

Parameters:

type - a valid expression type

See Also:

ExpressionTypes

*** This method is subject to change. ***

getValue

public java.lang.String getValue()

Description copied from interface: ConstantExpressionInterface

Return value of this constant in string form.

Specified by:

getValue in interface com.sas.iquery.metadata.expr.ConstantExpressionInterface

Returns:

the value of this constant as a String object If this expression's type is numeric check to make sure the returned value does not represent a SAS MissingValue before safely converting it to a number

See Also:

isMissing()

*** This method is subject to change. ***

setValue

public void setValue(java.lang.String value)

Sets the value of this constant as a String object

Specified by:

setValue in interface com.sas.iquery.metadata.expr.ConstantExpressionInterface

Parameters:

value - string to use as the constant

*** This method is subject to change. ***

isMissing

public boolean isMissing()

Checks if this ConstantExpression's value is a SAS MissingValue

Returns:

true if this contains a MissingValue false otherwise

See Also:

QueryMissingValues, getValue()

*** This class is subject to change. ***