er.extensions.eof
Class ERXEnterpriseObjectArrayCache<T extends EOEnterpriseObject>

java.lang.Object
  er.extensions.eof.ERXEnterpriseObjectArrayCache<T>

Direct Known Subclasses:

ERCEnterpriseObjectArrayCache

public class ERXEnterpriseObjectArrayCache<T extends EOEnterpriseObject>
extends Object

Caches objects of one entity by a given key. Listens to EOEditingContextDidSaveChanges notifications to track changes. Typically you'd fetch values by:

 ERXEnterpriseObjectArrayCache<HelpText> helpTextCache = new ERXEnterpriseObjectArrayCache<HelpText>("HelpText") {
    protected void handleUnsuccessfullQueryForKey(Object key) {
       NSArray helpTexts = ... fetch from somewhere
       setObjectsForKey(helpTexts, key);
   }
 };
 ...
 NSArray<HelpText> helpTexts = helpTextCache.objectsForKey(ec, "AllTexts");
 ...
 

You can supply a timeout after which the cache is to get cleared and all the objects refetched. Note that this implementation only caches the global IDs, not the actual data.

Author:

ak

Nested Class Summary

static class

ERXEnterpriseObjectArrayCache.NotFoundArray

Field Summary

protected static NSArray

NOT_FOUND_MARKER

Constructor Summary

ERXEnterpriseObjectArrayCache(Class c)
Creates the cache for the given entity name and the given keypath.

ERXEnterpriseObjectArrayCache(String entityName)
Creates the cache for the given entity name and the given keypath.

ERXEnterpriseObjectArrayCache(String entityName, long timeout)
Creates the cache for the given entity, keypath and timeout value in milliseconds.

Method Summary

protected NSArray<EOGlobalID>	cachedArrayForKey(Object key)
void	clearCaches(NSNotification n) Handler for the clearCaches notification.
void	editingContextDidSaveChanges(NSNotification n) Handler for the editingContextDidSaveChanges notification.
protected String	entityName()
protected static String	entityNameForClass(Class c)
protected long	fetchTime()
protected void	handleUnsuccessfullQueryForKey(Object key) Called when a query hasn't found an entry in the cache.
protected boolean	isNotFound(NSArray<EOGlobalID> gids)
NSArray<T>	objectsForKey(EOEditingContext ec, Object key) Retrieves a list of EOs that matches the given key or null if no match is in the cache.
protected void	registerForNotifications()
void	reset() Resets the cache by clearing the internal map.
protected void	setCachedArrayForKey(NSArray<EOGlobalID> gids, Object key)
void	setObjectsForKey(NSArray<? extends EOEnterpriseObject> bugs, Object key) Add a list of objects to the cache with the given key.
protected long	timeout()

Methods inherited from class java.lang.Object

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

Field Detail

NOT_FOUND_MARKER

protected static final NSArray NOT_FOUND_MARKER

Constructor Detail

ERXEnterpriseObjectArrayCache

public ERXEnterpriseObjectArrayCache(String entityName)

Creates the cache for the given entity name and the given keypath. No timeout value is used.

Parameters:

entityName -

ERXEnterpriseObjectArrayCache

public ERXEnterpriseObjectArrayCache(Class c)

Creates the cache for the given entity name and the given keypath. No timeout value is used.

ERXEnterpriseObjectArrayCache

public ERXEnterpriseObjectArrayCache(String entityName,
                                     long timeout)

Creates the cache for the given entity, keypath and timeout value in milliseconds.

Parameters:

entityName -

timeout -

Method Detail

entityNameForClass

protected static String entityNameForClass(Class c)

registerForNotifications

protected void registerForNotifications()

editingContextDidSaveChanges

public void editingContextDidSaveChanges(NSNotification n)

Handler for the editingContextDidSaveChanges notification. Calls reset if and object of the given entity were changed.

Parameters:

n -

clearCaches

public void clearCaches(NSNotification n)

Handler for the clearCaches notification. Calls reset if n.object is the entity name.

Parameters:

n -

entityName

protected String entityName()

setObjectsForKey

public void setObjectsForKey(NSArray<? extends EOEnterpriseObject> bugs,
                             Object key)

Add a list of objects to the cache with the given key. The object can be null.

Parameters:

bugs - array of objects

setCachedArrayForKey

protected void setCachedArrayForKey(NSArray<EOGlobalID> gids,
                                    Object key)

cachedArrayForKey

protected NSArray<EOGlobalID> cachedArrayForKey(Object key)

objectsForKey

public NSArray<T> objectsForKey(EOEditingContext ec,
                                Object key)

Retrieves a list of EOs that matches the given key or null if no match is in the cache.

Parameters:

ec - editing context to get the objects into

key - key value under which the objects are registered

isNotFound

protected boolean isNotFound(NSArray<EOGlobalID> gids)

handleUnsuccessfullQueryForKey

protected void handleUnsuccessfullQueryForKey(Object key)

Called when a query hasn't found an entry in the cache. This implementation puts a not-found marker in the cache so the next query will return null. You could override this method to create an EO with sensible default values and call setObjectsForKey(NSArray, Object) on it.

Parameters:

key -

reset

public void reset()

Resets the cache by clearing the internal map. When the next value is accessed, the objects are refetched.

timeout

protected long timeout()

fetchTime

protected long fetchTime()