Package com.streambase.sb.operator.parameter

Class SBExpressionPropertyDescriptor

java.lang.Object

java.beans.FeatureDescriptor

java.beans.PropertyDescriptor

com.streambase.sb.operator.parameter.SBPropertyDescriptor

com.streambase.sb.operator.parameter.SBExpressionPropertyDescriptor

public class SBExpressionPropertyDescriptor
extends SBPropertyDescriptor

A property descriptor that allows a user to define a property that supports StreamBase expressions. The user will always be presented with a text field to enter a StreamBase expression, and at runtime the server will evaluate the expression in the context of each tuple, and assign the result to the property associated with this descriptor. Studio will not call this property's setter during authoring.

Note that the Operator property may be of any Java primitive type, and the engine will attempt to coerce the result of the expression to the property. Care should be taken to ensure the expression evaluates to a type compatible with the property type used. For example:

• the expression text "max(input1.timeout,60.0)", given that timeout is a field of type double, is compatible with an Operator property of type double
• the expression text "input1.targetExecutionVenue", given that targetExecutionVenue is a field of type string, is compatible with an Operator property of type String

Properties can also be of type List or Tuple, but in those cases the read method for the property must have an SBExpressionPropertyType annotation to specify the exact StreamBase type of the property.

Since:

6.0, 6.6 support for properties of type "list" and "tuple"

See Also:

SBPropertyDescriptor, SBExpressionPropertyType

Nested Class Summary

Nested classes/interfaces inherited from class com.streambase.sb.operator.parameter.SBPropertyDescriptor

SBPropertyDescriptor.SingleValueSetter

Field Summary

Fields inherited from class com.streambase.sb.operator.parameter.SBPropertyDescriptor

_expressionInputPort, NOT_AN_EXPRESSION

Constructor Summary

Constructors

Constructor	Description
SBExpressionPropertyDescriptor(PropertyDescriptor pd, Class<?> beanClass, int expressionInputPort)	Copy a property descriptor.
SBExpressionPropertyDescriptor(String propertyName, Class<?> beanClass, int expressionInputPort)	Construct a property descriptor.
SBExpressionPropertyDescriptor(String propertyName, Class<?> beanClass, String readMethodName, String writeMethodName, int expressionInputPort)	Construct a property descriptor with non-standard read/write method names.

Method Summary

Methods inherited from class com.streambase.sb.operator.parameter.SBPropertyDescriptor

deprecated, description, displayName, getExpressionInputPort, getMaskDisplay, getMultiLine, getUIHints, isDeprecated, isExpression, isRequired, mask, multiline, optional, setDeprecated, setMaskStringDisplay, setMultiLine, setRequired, setUIHints

Methods inherited from class java.beans.PropertyDescriptor

createPropertyEditor, equals, getPropertyEditorClass, getPropertyType, getReadMethod, getWriteMethod, hashCode, isBound, isConstrained, setBound, setConstrained, setPropertyEditorClass, setReadMethod, setWriteMethod

Methods inherited from class java.beans.FeatureDescriptor

attributeNames, getDisplayName, getName, getShortDescription, getValue, isExpert, isHidden, isPreferred, setDisplayName, setExpert, setHidden, setName, setPreferred, setShortDescription, setValue, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

SBExpressionPropertyDescriptor

public SBExpressionPropertyDescriptor(String propertyName,
                                      Class<?> beanClass,
                                      String readMethodName,
                                      String writeMethodName,
                                      int expressionInputPort)
                               throws IntrospectionException

Construct a property descriptor with non-standard read/write method names.

Parameters:

propertyName - the name of the property

beanClass - the operator class containing the property

readMethodName - the name of the method used to read the property

writeMethodName - the name of the method used to write the property

expressionInputPort - the input port that this expression is valid against

Throws:

IntrospectionException - if introspection fails

SBExpressionPropertyDescriptor

public SBExpressionPropertyDescriptor(String propertyName,
                                      Class<?> beanClass,
                                      int expressionInputPort)
                               throws IntrospectionException

Construct a property descriptor.

Parameters:

propertyName - the name of the property

beanClass - the operator class containing the property

expressionInputPort - the input port that this expression is valid against

Throws:

IntrospectionException - if introspection fails

SBExpressionPropertyDescriptor

public SBExpressionPropertyDescriptor(PropertyDescriptor pd,
                                      Class<?> beanClass,
                                      int expressionInputPort)
                               throws IntrospectionException

Copy a property descriptor.

Parameters:

pd - a property descriptor to copy from

beanClass - the operator class containing the property

expressionInputPort - the input port that this expression is valid against

Throws:

IntrospectionException - if introspection fails