uk.ac.ed.epcc.safe.accounting.expr

Class DerivedPropertyMap

java.lang.Object

uk.ac.ed.epcc.safe.accounting.properties.PropertyMap

uk.ac.ed.epcc.safe.accounting.expr.DerivedPropertyMap

All Implemented Interfaces:

ExpressionTarget, PropertyContainer, PropertyTarget

public class DerivedPropertyMap
extends PropertyMap
implements ExpressionTarget

A PropertyMap that can also define derived properties. stored properties always take precidence even when a derived definition exists

Author:

spb

Constructor Summary

Constructors

Constructor and Description
DerivedPropertyMap(uk.ac.ed.epcc.webapp.AppContext c)

Method Summary

Methods

Modifier and Type	Method and Description
<T extends java.lang.Number> void	addDerived(PropertyTag<T> tag, PropExpression<? extends T> expr)
void	addDerived(PropExpressionMap map)
<T> T	evaluate(java.lang.Class<T> target, PropExpression texpr) evaluate a derived property expression.
<T> T	evaluateExpression(PropExpression<T> expr) Evaluate an expression on the target object
<T> T	evaluateExpression(PropExpression<T> expr, T def) Evaluate expression with default.
<T> T	getNonDerivedProperty(PropertyTag<T> key)
Parser	getParser() Get a Parser used to parse expressions for this target.
<T> T	getProperty(PropertyTag<T> key) Get the specified property from the container.
java.util.Set<PropertyTag>	propertySet()

Methods inherited from class uk.ac.ed.epcc.safe.accounting.properties.PropertyMap

getDefinedProperties, getProperty, setAll, setContainer, setOptionalProperty, setProperty, size, supports, writable

Methods inherited from class java.lang.Object

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

Methods inherited from interface uk.ac.ed.epcc.safe.accounting.properties.PropertyTarget

getProperty

Constructor Detail

DerivedPropertyMap

public DerivedPropertyMap(uk.ac.ed.epcc.webapp.AppContext c)

Method Detail

addDerived

public <T extends java.lang.Number> void addDerived(PropertyTag<T> tag,
                                           PropExpression<? extends T> expr)
                throws PropertyCastException

Throws:

PropertyCastException

addDerived

public void addDerived(PropExpressionMap map)

getProperty

public <T> T getProperty(PropertyTag<T> key)

Description copied from interface: PropertyContainer

Get the specified property from the container. THe InvalidPropertyException should only be thrown if the supports method would have returned false for the requested property.

Specified by:

getProperty in interface PropertyContainer

Overrides:

getProperty in class PropertyMap

Type Parameters:

T - type of property

Parameters:

key - PropertyTag identifying property

Returns:

value current value of property (may be null if not set).

getNonDerivedProperty

public <T> T getNonDerivedProperty(PropertyTag<T> key)

propertySet

public java.util.Set<PropertyTag> propertySet()

Overrides:

propertySet in class PropertyMap

evaluate

public <T> T evaluate(java.lang.Class<T> target,
             PropExpression texpr)
           throws java.lang.Exception

evaluate a derived property expression. To prevent infinite recursion due to self referential property definitions this call has a limited recursion depth.

Throws:

java.lang.Exception

Type Parameters:

T - Type of expression

Parameters:

target - target class

texpr - expression to evaluate

Returns:

Number value

getParser

public Parser getParser()

Description copied from interface: ExpressionTarget

Get a Parser used to parse expressions for this target.

Specified by:

getParser in interface ExpressionTarget

Returns:

Parser

evaluateExpression

public <T> T evaluateExpression(PropExpression<T> expr)
                     throws InvalidPropertyException

Description copied from interface: ExpressionTarget

Evaluate an expression on the target object

Specified by:

evaluateExpression in interface ExpressionTarget

Throws:

InvalidPropertyException

Type Parameters:

T - type of expression

Parameters:

expr - expression

Returns:

T

evaluateExpression

public <T> T evaluateExpression(PropExpression<T> expr,
                       T def)

Description copied from interface: ExpressionTarget

Evaluate expression with default. If the expression does not resolve then return the default value

Specified by:

evaluateExpression in interface ExpressionTarget

Type Parameters:

T - type of expression

Parameters:

expr - expression

def - default value

Returns:

T