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/*--------------------------------------------------------------------------
*
* You may freely copy, distribute, and reuse the code in this example.
* SHL Systemhouse disclaims any warranty of any kind, expressed or
* implied, as to its fitness for any particular use.
*
*
* Database
*
* Category Of: EOFDelegate
*
* Conforms To: None
*
* Declared In: EOFDelegateDatabaseCategory.h
*
*
*------------------------------------------------------------------------*/
#import "EOFDelegateDatabaseCategory.h"
@implementation EOFDelegate (Database)
/*--------------------------------------------------------------------------
* EODatabaseChannel Delegate Methods
*------------------------------------------------------------------------*/
- databaseChannel:channel willInsertObject:object
{
// Invoked from -insertObject: to tell the delegate that an object will
// be inserted. The delegate may return the object, a substitute, or nil
// to prevent insertion.
id result = object;
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObject:object]];
if ([[NXApp delegate] wantsAlertPanels] == YES)
{
switch (NXRunAlertPanel ("EODatabaseChannel",
"%s", "YES", "NO", NULL, sel_getName(_cmd)))
{
case NX_ALERTALTERNATE:
result = nil;
break;
case NX_ALERTDEFAULT:
default:
result = object;
break;
}
}
return result;
}
- (void)databaseChannel:channel didInsertObject:object
{
// Invoked from -insertObject: to tell the delegate that
// an object was inserted.
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObject:object]];
}
- databaseChannel:channel willDeleteObject:object
{
// Invoked from -deleteObject: to tell the delegate that an object will
// be deleted. The delegate may return the object, a substitute, or nil
// to prevent deletion.
id result = object;
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObject:object]];
if ([[NXApp delegate] wantsAlertPanels] == YES)
{
switch (NXRunAlertPanel ("EODatabaseChannel",
"%s", "YES", "NO", NULL, sel_getName(_cmd)))
{
case NX_ALERTALTERNATE:
result = nil;
break;
case NX_ALERTDEFAULT:
default:
result = object;
break;
}
}
return result;
}
- (void)databaseChannel:channel didDeleteObject:object
{
// Invoked from -deleteObject: to tell the delegate that
// an object was deleted.
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObject:object]];
}
- databaseChannel:channel willUpdateObject:object
{
// Invoked from -updateObject: to tell the delegate that an object will
// be updated. The delegate may return the object, a substitute, or nil
// to prevent updating.
id result = object;
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObject:object]];
if ([[NXApp delegate] wantsAlertPanels] == YES)
{
switch (NXRunAlertPanel ("EODatabaseChannel",
"%s", "YES", "NO", NULL, sel_getName(_cmd)))
{
case NX_ALERTALTERNATE:
result = nil;
break;
case NX_ALERTDEFAULT:
default:
result = object;
break;
}
}
return result;
}
- (void)databaseChannel:channel didUpdateObject:object
{
// Invoked from -updateObject: to tell the delegate that
// an object was updated.
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObject:object]];
}
- (NSDictionary *)databaseChannel:channel
willRefetchObject:object
fromSnapshot:(NSDictionary *)snapshot
{
// Invoked whenever an object that was previously fetched is fetched again
// and the re-fetched data is different from that in the object. The
// object will be refetched with the dictionary returned by this method,
// which may be the snapshot provided or a substitute. The delegate may
// also return nil to prevent the object from being refetched.
id result = object;
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObjects: object, snapshot, nil]];
if ([[NXApp delegate] wantsAlertPanels] == YES)
{
switch (NXRunAlertPanel ("EODatabaseChannel",
"%s", "YES", "NO", NULL, sel_getName(_cmd)))
{
case NX_ALERTALTERNATE:
result = nil;
break;
case NX_ALERTDEFAULT:
default:
result = object;
break;
}
}
return result;
}
- (void)databaseChannel:channel
failedToRefetchObject:object
withValues:(NSDictionary *)snapshot
{
// Invoked whenever an object that was previously fetched is fetched
// again, to tell the delegate that object can't be reliably refetched
// because it's been updated in a transaction that hasn't been committed.
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObjects: object, snapshot, nil]];
}
- (BOOL)databaseChannel:channel
willSelectObjectsDescribedByQualifier:(EOQualifier *)qualifier
fetchOrder:(NSMutableArray *)fetchOrder
{
// Invoked from -selectObjectsDescribedByQualifier:... to tell the
// delegate that the channel will select objects as specified by
// qualifier. The delegate can modify the qualifier and fetch order. If
// the delegate returns YES the channel will go ahead and select the
// object; if the delegate returns NO the channel will abort the select
// and return NO.
BOOL result = YES;
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObjects: qualifier, fetchOrder, nil]];
if ([[NXApp delegate] wantsAlertPanels] == YES)
{
switch (NXRunAlertPanel ("EODatabaseChannel",
"%s", "YES", "NO", NULL, sel_getName(_cmd)))
{
case NX_ALERTALTERNATE:
result = NO;
break;
case NX_ALERTDEFAULT:
default:
result = YES;
break;
}
}
return result;
}
- (void)databaseChannel:channel
didSelectObjectsDescribedByQualifier:(EOQualifier *)qualifier
fetchOrder:(NSArray *)fetchOrder
{
// Invoked from -selectObjectsDescribedByQualifier:... to tell the
// delegate that the channel selected objects as specified by qualifier.
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObjects: qualifier, fetchOrder, nil]];
}
- (void)databaseChannel:channel
willFetchObjectOfClass:(Class)class
withZone:(NSZone *)zone
{
// Invoked from -fetchWithZone: to tell the delegate that
// the channel willfetch the next selected object.
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObject:class]];
}
- (void)databaseChannel:channel didFetchObject:object
{
// Invoked from -fetchWithZone: to tell the delegate that
// the channel fetched the next selected object.
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObject:object]];
}
- (BOOL)databaseChannel:channel willLockObject:object
{
// Invoked from -lockObject: to tell the delegate that object will be
// locked using snapshot data to determine whether the database has been
// modified. The delegate may return YES to allow the channel to proceed,
// or NO to cause the operation to fail and -lockObject: to return NO.
BOOL result = YES;
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObject:object]];
if ([[NXApp delegate] wantsAlertPanels] == YES)
{
switch (NXRunAlertPanel ("EODatabaseChannel",
"%s", "YES", "NO", NULL, sel_getName(_cmd)))
{
case NX_ALERTALTERNATE:
result = NO;
break;
case NX_ALERTDEFAULT:
default:
result = YES;
break;
}
}
return result;
}
- (void)databaseChannel:channel didLockObject:object
{
// Invoked from -lockObject: to tell the delegate that
// object was locked.
[[NXApp delegate] announce:channel
selector:_cmd
with:[NSArray arrayWithObject:object]];
}
@end
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.