uk.ac.ed.epcc.webapp.model.data

Class IndexedLinkManager.Link<L extends Indexed,R extends Indexed>

java.lang.Object

uk.ac.ed.epcc.webapp.model.data.DataObject

uk.ac.ed.epcc.webapp.model.data.IndexedLinkManager.Link<L,R>

Type Parameters:

L - Left end type

R - Right end type

All Implemented Interfaces:

Contexed, ContextIndexed, Identified, Indexed, Owned, Releasable

Direct Known Subclasses:

LinkManager.Link

Enclosing class:

IndexedLinkManager<T extends IndexedLinkManager.Link<L,R>,L extends Indexed,R extends Indexed>

public abstract static class IndexedLinkManager.Link<L extends Indexed,R extends Indexed>
extends DataObject
implements Owned

Link is an object representing an entry in a linkage table. Link objects are not primary model objects themselves but represent many to one relationships between model objects. To a first approximation Link objects only contain references to the 2 model objects on the ends of the links In many cases we will also want to add status and Date fields

Link objects are pseudo inner classes. We make the manage reference explicit to avoid Link being generic parameterised by itself.

The appropriate LinkManager Link should always be subclasses to improve type safety. The getLeft()/getRight() methods are made protected to force us to add sensibly named accessors in sub-classes

Field Summary

Fields inherited from class uk.ac.ed.epcc.webapp.model.data.DataObject

DEBUG, record

Fields inherited from interface uk.ac.ed.epcc.webapp.forms.Identified

MAX_IDENTIFIER

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Link(IndexedLinkManager<?,L,R> man, Repository.Record res)

Method Summary

Modifier and Type	Method and Description
protected void	changeLeft(L left)
protected void	changeRight(R right)
DataObjectFactory	getFactory()
protected IndexedLinkManager	getIndexedLinkManager() allow sub-classes to get the LinkManager don't make the return type generic its much easier for sub-classes to implement getFactory() methods that cast correctly than have a generic signature that can be used use-fully type checking is preserved by getting the constructor right
protected L	getLeft() get the Left end object
protected java.lang.Number	getLeftID()
protected R	getRight() get the Right end object
protected java.lang.Number	getRightID()
boolean	isLeftPeer(L o)
boolean	isRightPeer(R o)
void	post_commit(boolean changed) Extension point called at end of commit
protected void	pre_commit(boolean dirty) Extension point called at start of commit.
void	release() This is used like a destructor - means less connections, etc lying around This will also clear the record from the Repository cache if this is enabled
protected void	setCachedLeft(L o) pass in a copy of the Left end object to initialise the cache.
protected void	setCachedRight(R o) pass in a copy of the Right end object to initialise the cache.
protected abstract void	setup() extension point for Link subclasses this method is called when new records are created to initialise subclass fields to sensible default values

Methods inherited from class uk.ac.ed.epcc.webapp.model.data.DataObject

addToMap, addToMap, addToMap, commit, delete, empty, equals, formUpdate, getContext, getDatabaseService, getFactoryTag, getID, getIdentifier, getIdentifier, getLogger, getMap, getMap, getOwningFactory, getRecord, getRecord, getRecord, getSQLContext, getUniqueIdName, hashCode, isLocked, lock, postCreate, setContents, setDirty, setMap, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

Link

protected Link(IndexedLinkManager<?,L,R> man,
               Repository.Record res)

Method Detail

getIndexedLinkManager

protected IndexedLinkManager getIndexedLinkManager()

allow sub-classes to get the LinkManager don't make the return type generic its much easier for sub-classes to implement getFactory() methods that cast correctly than have a generic signature that can be used use-fully type checking is preserved by getting the constructor right

Returns:

getFactory

public DataObjectFactory getFactory()

Specified by:

getFactory in interface Owned

post_commit

public void post_commit(boolean changed)
                 throws DataFault

Description copied from class: DataObject

Extension point called at end of commit

Overrides:

post_commit in class DataObject

Parameters:

changed - record was changed by commit.

Throws:

DataFault

release

public void release()

Description copied from class: DataObject

This is used like a destructor - means less connections, etc lying around This will also clear the record from the Repository cache if this is enabled

Specified by:

release in interface Releasable

Overrides:

release in class DataObject

getLeft

protected final L getLeft()
                   throws DataException

get the Left end object

Returns:

DataObject

Throws:

DataException

getLeftID

protected final java.lang.Number getLeftID()

getRight

protected final R getRight()
                    throws DataException

get the Right end object

Returns:

DataObject

Throws:

DataException

getRightID

protected final java.lang.Number getRightID()

isLeftPeer

public final boolean isLeftPeer(L o)

isRightPeer

public final boolean isRightPeer(R o)

setCachedLeft

protected final void setCachedLeft(L o)

pass in a copy of the Left end object to initialise the cache. Note that this method will do NOTHING if the argument is not the current Left peer or the reference is not yet set.

Parameters:

o - DataObject

setCachedRight

protected final void setCachedRight(R o)

pass in a copy of the Right end object to initialise the cache. Note that this method will do NOTHING if the argument is not the current Right peer or the reference is not yet set.

Parameters:

o - DataObject

changeLeft

protected final void changeLeft(L left)

changeRight

protected final void changeRight(R right)

setup

protected abstract void setup()
                       throws java.lang.Exception

extension point for Link subclasses this method is called when new records are created to initialise subclass fields to sensible default values

Throws:

java.lang.Exception

pre_commit

protected void pre_commit(boolean dirty)
                   throws DataFault

Description copied from class: DataObject

Extension point called at start of commit. It is legal to change the record in this call

Overrides:

pre_commit in class DataObject

Parameters:

dirty - is record known to be modified.

Throws:

DataFault