blackboard.data
Class BbAttribute

java.lang.Object
  blackboard.data.BbAttribute

public class BbAttribute
extends java.lang.Object

The BbAttribute class is used to form the basis of the name/value pairs used for IBbObject based object properties. Beyond the basic name and value information, this object also provides additional information regarding the "state" of an attribute. This "state" information is internally controlled and should be useful in some special circumstances.

This object can not be directed instantiated or manipulated and therefore, the majority of interaction with it will be through its parent container BbAttributes.

Since:

Bb 6.0

Version:

$Revision: #1 $ $Date: 2007/06/27 $

Nested Class Summary

static class

BbAttribute.Type

Constructor Summary

protected

BbAttribute(BbAttribute.Type eType, java.lang.String strName, java.lang.Object val, BbAttributes parent) Initialization with generic object but of a specific type.

Method Summary

boolean	getIsDirty() Get the "dirty" status of this BbAttribute.
boolean	getIsReadOnly() Returns value of the isReadOnly flag.
boolean	getIsSet() Retrieve "set" status of this BbAtribute.
java.lang.String	getName() Retrieves name ("key") associated with this BbAttribute object.
BbAttribute.Type	getType() Retrieves BbAttribute object type.
java.lang.Object	getValue() Retrieves object value associated with BbAttribute object.
void	setIsDirty(boolean bIsDirty) Sets "dirty" (changed) status of BbAttribute
void	setIsReadOnly(boolean isReadOnly) Sets the value of the isReadOnly flag.
protected void	setIsSet(boolean bIsSet) Sets the "has been set" status of this BbAttribute.
protected void	setValue() Sets the value of this BbAttribute to "unset".
void	setValue(java.lang.Object val) Sets value object with type Object.
java.lang.String	toString() Converts this BbAttribute value to a string representation.

Methods inherited from class java.lang.Object

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

Constructor Detail

BbAttribute

protected BbAttribute(BbAttribute.Type eType,
                      java.lang.String strName,
                      java.lang.Object val,
                      BbAttributes parent)

Initialization with generic object but of a specific type.

Parameters:

eType - The BbAttribute.Type describing the attribute object type.

strName - The string describing the attributes key.

val - The Object describing the attributes value.

parent - the parent BbAttributes object that will "contain" this attribute.

Method Detail

getName

public java.lang.String getName()

Retrieves name ("key") associated with this BbAttribute object.

Returns:

String BbAttribute name ("key") value.

getType

public BbAttribute.Type getType()

Retrieves BbAttribute object type.

Returns:

a type value as defined in BbAttribute.Type

getIsReadOnly

public boolean getIsReadOnly()

Returns value of the isReadOnly flag. If an attribute is read-only, attempting to set it would result in an ImmutableException being thrown

Returns:

Returns whether this value can be set.

setIsReadOnly

public void setIsReadOnly(boolean isReadOnly)

Sets the value of the isReadOnly flag.

Parameters:

isReadOnly - The isReadOnly to set.

getValue

public java.lang.Object getValue()

Retrieves object value associated with BbAttribute object.

Returns:

Object Reference to attribute value object.

setValue

protected void setValue()

Sets the value of this BbAttribute to "unset". The "unset" case results in an ambiguous attribute value but will result in a sensible default being used should the attribute value be retrieved. The "unset" case will typically signify the state where an attribute value has not been loaded as in the case of a "light-weight" load being performed. In this case, the objects contained by the heavy object will have not been loaded and therefore be in an "unset" state.

setValue

public void setValue(java.lang.Object val)

Sets value object with type Object.

NOTE: this method does no checking of the provided value to make sure it makes sense given the type of the attribute. Since this method is protected it is assumed that any caller has already validated this and it is therefore not necessary here.

Parameters:

val - The new attribute value.

getIsSet

public boolean getIsSet()

Retrieve "set" status of this BbAtribute. Unless an attribute value is "set", any value retrieved through getValue() will be ambiguous. The value provided by an attribute in an "unset" state could be any default value the attribute deems appropriate based upon its type, although the typical return value will be null.

Returns:

boolean the "set" status of this BbAttribute. true if the object value has been "set", false otherwise.

setIsSet

protected void setIsSet(boolean bIsSet)

Sets the "has been set" status of this BbAttribute.

Parameters:

bIsSet - boolean flag denoting whether this attribute is "set".

getIsDirty

public boolean getIsDirty()

Get the "dirty" status of this BbAttribute. An attribute is "dirty" if it value has been changed sinced a saved state. A BbAttribute starts out "dirty" since it has yet to be saved to any location.

Returns:

boolean Returns "dirty" status of this BbAttribute. true if the attribute is "dirty", false otherwise.

setIsDirty

public void setIsDirty(boolean bIsDirty)

Sets "dirty" (changed) status of BbAttribute

Parameters:

bIsDirty - boolean flag denoting whether a change has been made to this attribute.

toString

public java.lang.String toString()

Converts this BbAttribute value to a string representation. Can be used for debug purposes.

Overrides:

toString in class java.lang.Object

Returns:

a String describing the name and value of this BbAttribute