AccessorMap.ExpressionTargetProxy

java.lang.Object
- uk.ac.ed.epcc.safe.accounting.expr.EvaluatePropExpressionVisitor
- - uk.ac.ed.epcc.safe.accounting.db.AccessorMap.ExpressionTargetProxy

All Implemented Interfaces:

ExpressionTarget, ExpressionTargetContainer, PropExpressionVisitor<java.lang.Object>, BasePropExpressionVisitor<java.lang.Object>, PropertyContainer, PropertyTarget, uk.ac.ed.epcc.webapp.Contexed

Enclosing class:

AccessorMap<X extends uk.ac.ed.epcc.webapp.model.data.DataObject & ExpressionTarget>
```
public class AccessorMap.ExpressionTargetProxy
extends EvaluatePropExpressionVisitor
implements ExpressionTargetContainer
```
Class to evaluate a PropExpression on a record. This acts as a proxy implementing most of ExpressionTargetContainer via the Accessors. Note that the getExpressionTargetFactory method is forwarded to the underlying object. Application classes will usually implement ExpressionTarget by holding a reference to one of these. This class can also implements a cache of result values that is populated by calling the evaluate method and cleared with the flush method. This allows a record to hold a copy of its own visitor and use it as a value cache.

Author:

spb

Constructor Summary

Constructors
Constructor and Description

AccessorMap.ExpressionTargetProxy(X r)

AccessorMap.ExpressionTargetProxy(X r, boolean use_cache)

Constructors
Constructor and Description
`AccessorMap.ExpressionTargetProxy(X r)`
`AccessorMap.ExpressionTargetProxy(X r, boolean use_cache)`

Method Summary

Methods
Modifier and Type	Method and Description
`<R> R`	`evaluateExpression(PropExpression<R> expr)` Evaluate an expression on the target object
`<R> R`	`evaluateExpression(PropExpression<R> expr, R def)` Evaluate expression with default.
`void`	`flush()`
`java.util.Set<PropertyTag>`	`getDefinedProperties()` Generate a set of all the properties defined in this container
`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.
`<T> T`	`getProperty(PropertyTag<T> tag, T def)` Get property with default.
`protected boolean`	`matches(RecordSelector sel)` Check if a `RecordSelector` matches the target object
`void`	`reset()`
`void`	`setAll(PropertyContainer source)` Copy all compatible properties from one container to another;
`<T> void`	`setOptionalProperty(PropertyTag<? super T> t, T value)` Set the specified property if it is supported
`<T> void`	`setProperty(PropertyTag<? super T> t, T value)` Set the specified property
`boolean`	`supports(PropertyTag<?> tag)` Is the specified property supported by the container.
`java.lang.Object`	`visitPropertyTag(PropertyTag<?> tag)`
`boolean`	`writable(PropertyTag<?> tag)` Is the specified property supported for write.

Methods inherited from class uk.ac.ed.epcc.safe.accounting.expr.EvaluatePropExpressionVisitor
getContext, visitBinaryPropExpression, visitCasePropExpression, visitConstPropExpression, visitConvetMillisecondToDateExpression, visitDeRefExpression, visitDoublePropExpression, visitDurationCastPropExpression, visitDurationPropExpression, visitDurationSecondPropExpression, visitIntPropExpression, visitLabelPropExpression, visitMilliSecondDatePropExpression, visitNamePropExpression, visitSelectPropExpression, visitStringPropExpression, visitTypeConverterPropExpression

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - AccessorMap.ExpressionTargetProxy
```
public AccessorMap.ExpressionTargetProxy(X r,
                                 boolean use_cache)
```
  - AccessorMap.ExpressionTargetProxy
```
public AccessorMap.ExpressionTargetProxy(X r)
```
- Method Detail
  - evaluateExpression
```
public <R> R evaluateExpression(PropExpression<R> 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:
    R - type of expression
    Parameters:
    expr - expression
    
    Returns:
    T
  - evaluateExpression
```
public <R> R evaluateExpression(PropExpression<R> expr,
                       R 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:
    R - type of expression
    Parameters:
    expr - expression
    def - default value
    
    Returns:
    T
  - flush
```
public void flush()
```
  - setProperty
```
public <T> void setProperty(PropertyTag<? super T> t,
                   T value)
                 throws InvalidPropertyException
```
    Description copied from interface: PropertyContainer
    
    Set the specified property
    
    Specified by:
    
    setProperty in interface PropertyContainer
    
    Throws:
    
    InvalidPropertyException
    Type Parameters:
    T - type of property
    Parameters:
    t - PropertyTag identifying property
  - setOptionalProperty
```
public <T> void setOptionalProperty(PropertyTag<? super T> t,
                           T value)
```
    Description copied from interface: PropertyContainer
    
    Set the specified property if it is supported
    
    Specified by:
    
    setOptionalProperty in interface PropertyContainer
    
    Type Parameters:
    T - type of property
    Parameters:
    t - PropertyTag identifying property
  - visitPropertyTag
```
public java.lang.Object visitPropertyTag(PropertyTag<?> tag)
                                  throws java.lang.Exception
```
    Specified by:
    
    visitPropertyTag in interface BasePropExpressionVisitor<java.lang.Object>
    
    Throws:
    
    java.lang.Exception
  - reset
```
public void reset()
```
  - getProperty
```
public <T> T getProperty(PropertyTag<T> tag,
                T def)
```
    Description copied from interface: PropertyTarget
    
    Get property with default. If the property is not supported by the container of if no value has been set then the default value is returned.
    
    Specified by:
    
    getProperty in interface PropertyTarget
    
    Type Parameters:
    T - Type of property
    Parameters:
    tag - PropertTag identifying property
    def - default value
    
    Returns:
    property value or default.
  - supports
```
public boolean supports(PropertyTag<?> tag)
```
    Description copied from interface: PropertyContainer
    
    Is the specified property supported by the container. If the container is unconstrained this always returns true
    
    Specified by:
    
    supports in interface PropertyContainer
    
    Returns:
    boolean true if property supported
  - getProperty
```
public <T> T getProperty(PropertyTag<T> key)
              throws InvalidPropertyException
```
    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
    
    Throws:
    
    InvalidPropertyException
    Type Parameters:
    T - type of property
    Parameters:
    key - PropertyTag identifying property
    
    Returns:
    value current value of property (may be null if not set).
  - writable
```
public boolean writable(PropertyTag<?> tag)
```
    Description copied from interface: PropertyContainer
    
    Is the specified property supported for write. If the container is unconstrained this always returns true
    
    Specified by:
    
    writable in interface PropertyContainer
    
    Returns:
    boolean true if property can be written
  - getDefinedProperties
```
public java.util.Set<PropertyTag> getDefinedProperties()
```
    Description copied from interface: PropertyContainer
    
    Generate a set of all the properties defined in this container
    
    Specified by:
    
    getDefinedProperties in interface PropertyContainer
    
    Returns:
    Set
  - setAll
```
public void setAll(PropertyContainer source)
```
    Description copied from interface: PropertyContainer
    
    Copy all compatible properties from one container to another;
    
    Specified by:
    
    setAll in interface PropertyContainer
    
    Parameters:
    source - PropertyContainer
  - 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
  - matches
```
protected boolean matches(RecordSelector sel)
                   throws java.lang.Exception
```
    Description copied from class: EvaluatePropExpressionVisitor
    
    Check if a RecordSelector matches the target object
    
    Specified by:
    
    matches in class EvaluatePropExpressionVisitor
    
    Throws:
    
    java.lang.Exception
    
    Returns:

Class AccessorMap.ExpressionTargetProxy

Constructor Summary

Method Summary

Methods inherited from class uk.ac.ed.epcc.safe.accounting.expr.EvaluatePropExpressionVisitor

Methods inherited from class java.lang.Object

Constructor Detail

AccessorMap.ExpressionTargetProxy

AccessorMap.ExpressionTargetProxy

Method Detail

evaluateExpression

evaluateExpression

flush

setProperty

setOptionalProperty

visitPropertyTag

reset

getProperty

supports

getProperty

writable

getDefinedProperties

setAll

getParser

matches