Fix for batch updating with multiple transform lists

RZCollectionList/Classes/RZArrayCollectionList.h

@@ -10,7 +10,7 @@
 #import "RZCollectionListProtocol.h"
 #import "RZBaseCollectionList.h"
 
-@interface RZArrayCollectionListSectionInfo : NSObject <RZCollectionListSectionInfo, NSCopying>
+@interface RZArrayCollectionListSectionInfo : NSObject <RZCollectionListSectionInfo>
 
 @property (nonatomic, assign) NSUInteger indexOffset;
 

RZCollectionList/Classes/RZArrayCollectionList.m

@@ -14,10 +14,13 @@ @interface RZArrayCollectionListSectionInfo ()
 
 @property (nonatomic, readwrite) NSString *name;
 @property (nonatomic, readwrite) NSString *indexTitle;
+@property (nonatomic, strong, readwrite) NSArray *objects;
 @property (nonatomic, assign, readwrite) NSUInteger numberOfObjects;
 
 @property (nonatomic, weak) RZArrayCollectionList *arrayList;
 
+@property (nonatomic, assign) BOOL isCachedCopy;
+
 - (NSRange)range;
 
 @end
@@ -57,6 +60,10 @@ - (void)removeSectionAtIndex:(NSUInteger)index sendNotifications:(BOOL)shouldSen
 // Helpers for batch update
 - (NSIndexPath*)previousIndexPathForObject:(id)object;
 
+// if not in a batch update, send necessary notifications, etc
+- (void)prepareForUpdateIfNecessary;
+- (void)finalizeUpdateIfNecessary;
+
 - (void)sendDidChangeObjectNotification:(id)object atIndexPath:(NSIndexPath*)indexPath forChangeType:(RZCollectionListChangeType)type newIndexPath:(NSIndexPath*)newIndexPath;
 - (void)sendDidChangeSectionNotification:(id<RZCollectionListSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex  forChangeType:(RZCollectionListChangeType)type;
 
@@ -193,17 +200,9 @@ - (void)addObject:(id)object toSection:(NSUInteger)section
 
 - (void)insertObject:(id)object atIndexPath:(NSIndexPath*)indexPath
 {
-    if (!self.batchUpdating)
-    {
-        [self sendWillChangeContentNotifications];
-    }
-
+    [self prepareForUpdateIfNecessary];
     [self insertObject:object atIndexPath:indexPath sendNotifications:!self.batchUpdating];
-
-    if (!self.batchUpdating)
-    {
-        [self sendDidChangeContentNotifications];
-    }
+    [self finalizeUpdateIfNecessary];
 }
 
 - (void)removeObject:(id)object
@@ -218,47 +217,23 @@ - (void)removeObject:(id)object
 
 - (void)removeObjectAtIndexPath:(NSIndexPath*)indexPath
 {
-    if (!self.batchUpdating)
-    {
-        [self sendWillChangeContentNotifications];
-    }
-
+    [self prepareForUpdateIfNecessary];
     [self removeObjectAtIndexPath:indexPath sendNotifications:!self.batchUpdating];
-
-    if (!self.batchUpdating)
-    {
-        [self sendDidChangeContentNotifications];
-    }
+    [self finalizeUpdateIfNecessary];
 }
 
 - (void)replaceObjectAtIndexPath:(NSIndexPath*)indexPath withObject:(id)object
 {
-    if (!self.batchUpdating)
-    {
-        [self sendWillChangeContentNotifications];
-    }
-
+    [self prepareForUpdateIfNecessary];
     [self replaceObjectAtIndexPath:indexPath withObject:object sendNotifications:!self.batchUpdating];
-
-    if (!self.batchUpdating)
-    {
-        [self sendDidChangeContentNotifications];
-    }
+    [self finalizeUpdateIfNecessary];
 }
 
 - (void)moveObjectAtIndexPath:(NSIndexPath*)sourceIndexPath toIndexPath:(NSIndexPath*)destinationIndexPath
 {
-    if (!self.batchUpdating)
-    {
-        [self sendWillChangeContentNotifications];
-    }
-
+    [self prepareForUpdateIfNecessary];
     [self moveObjectAtIndexPath:sourceIndexPath toIndexPath:destinationIndexPath sendNotifications:!self.batchUpdating];
-
-    if (!self.batchUpdating)
-    {
-        [self sendDidChangeContentNotifications];
-    }
+    [self finalizeUpdateIfNecessary];
 }
 
 - (void)removeAllObjects
@@ -277,17 +252,9 @@ - (void)addSection:(RZArrayCollectionListSectionInfo*)section
 
 - (void)insertSection:(RZArrayCollectionListSectionInfo*)section atIndex:(NSUInteger)index
 {
-    if (!self.batchUpdating)
-    {
-        [self sendWillChangeContentNotifications];
-    }
-
+    [self prepareForUpdateIfNecessary];
     [self insertSection:section atIndex:index sendNotifications:!self.batchUpdating];
-
-    if (!self.batchUpdating)
-    {
-        [self sendDidChangeContentNotifications];
-    }
+    [self finalizeUpdateIfNecessary];
 }
 
 - (void)removeSection:(RZArrayCollectionListSectionInfo*)section
@@ -299,17 +266,9 @@ - (void)removeSection:(RZArrayCollectionListSectionInfo*)section
 
 - (void)removeSectionAtIndex:(NSUInteger)index
 {
-    if (!self.batchUpdating)
-    {
-        [self sendWillChangeContentNotifications];
-    }
-
+    [self prepareForUpdateIfNecessary];
     [self removeSectionAtIndex:index sendNotifications:!self.batchUpdating];
-
-    if (!self.batchUpdating)
-    {
-        [self sendDidChangeContentNotifications];
-    }
+    [self finalizeUpdateIfNecessary];
 }
 
 - (void)beginUpdates
@@ -321,7 +280,7 @@ - (void)beginUpdates
 
         // shallow copy sections
         self.sourceSectionsInfoBeforeUpdateShallow = [self.sectionsInfo copy];
-        self.sourceSectionsInfoBeforeUpdateDeep = [[NSArray alloc] initWithArray:self.sectionsInfo copyItems:YES];
+        self.sourceSectionsInfoBeforeUpdateDeep = [self.sectionsInfo valueForKey:@"cachedCopy"];
 
         [self sendWillChangeContentNotifications];
     }
@@ -334,6 +293,11 @@ - (void)endUpdates
         [self processPendingChangeNotifications];
         [self sendAllPendingChangeNotifications];
         [self sendDidChangeContentNotifications];
+
+        self.sourceObjectsBeforeUpdate = nil;
+        self.sourceSectionsInfoBeforeUpdateShallow = nil;
+        self.sourceSectionsInfoBeforeUpdateDeep = nil;
+
         self.batchUpdating = NO;
     }
 }
@@ -618,6 +582,25 @@ - (NSIndexPath*)previousIndexPathForObject:(id)object
 
 #pragma mark - Notification Helpers
 
+- (void)prepareForUpdateIfNecessary
+{
+    if (!self.batchUpdating)
+    {
+        // always need to have valid cached sections before sending willChange
+        self.sourceSectionsInfoBeforeUpdateDeep = [self.sectionsInfo valueForKey:@"cachedCopy"];
+        [self sendWillChangeContentNotifications];
+    }
+}
+
+- (void)finalizeUpdateIfNecessary
+{
+    if (!self.batchUpdating)
+    {
+        [self sendDidChangeContentNotifications];
+        self.sourceSectionsInfoBeforeUpdateDeep = nil;
+    }
+}
+
 - (void)sendDidChangeObjectNotification:(id)object atIndexPath:(NSIndexPath*)indexPath forChangeType:(RZCollectionListChangeType)type newIndexPath:(NSIndexPath*)newIndexPath
 {
 #if kRZCollectionListNotificationsLogging
@@ -733,7 +716,7 @@ - (void)objectUpdateNotificationReceived:(NSNotification*)notification
         {
             [self sendWillChangeContentNotifications];
 
-            [self sendDidChangeObjectNotification:object atIndexPath:indexPath forChangeType:RZCollectionListChangeUpdate newIndexPath:nil];
+            [self sendDidChangeObjectNotification:object atIndexPath:indexPath forChangeType:RZCollectionListChangeUpdate newIndexPath:indexPath];
 
             [self sendDidChangeContentNotifications];
         }
@@ -856,6 +839,16 @@ - (NSArray*)sections
     return [self.sectionsInfo copy];
 }
 
+- (NSArray*)cachedSections
+{
+    // if we aren't updating, just return regular sections
+    if (nil != self.sourceSectionsInfoBeforeUpdateDeep)
+    {
+        return [self.sourceSectionsInfoBeforeUpdateDeep copy];
+    }
+    return self.sections;
+}
+
 - (NSArray*)sectionIndexTitles
 {
     NSMutableArray *indexTitles = [NSMutableArray arrayWithCapacity:self.sectionsInfo.count];
@@ -987,6 +980,10 @@ - (NSString*)indexTitle
 
 - (NSArray*)objects
 {
+    if (self.isCachedCopy)
+    {
+        return _objects;
+    }
     return [self.arrayList.listObjects subarrayWithRange:NSMakeRange(self.indexOffset, self.numberOfObjects)];
 }
 
@@ -1000,10 +997,13 @@ - (NSString*)description
     return [NSString stringWithFormat:@"%@ Name:%@ IndexTitle:%@ IndexOffset:%u NumberOfObjects:%u", [super description], self.name, self.indexTitle, self.indexOffset, self.numberOfObjects];
 }
 
-- (id)copyWithZone:(NSZone *)zone
+- (id<RZCollectionListSectionInfo>)cachedCopy
 {
     RZArrayCollectionListSectionInfo *copy = [[RZArrayCollectionListSectionInfo alloc] initWithName:self.name sectionIndexTitle:self.indexTitle numberOfObjects:self.numberOfObjects];
+    copy.arrayList = self.arrayList;
     copy.indexOffset = self.indexOffset;
+    copy.objects = self.objects;
+    copy.isCachedCopy = YES;
     return copy;
 }
 

RZCollectionList/Classes/RZBaseCollectionList.h

@@ -11,17 +11,16 @@
 
 /***************************************************************
  *
- * Base class for providing common variables and
- * utils for RZCollectionList "source" lists, i.e.
- * lists that maintain/represent a concrete collection
- * of objects, rather than a "modified" collection.
- * 
- * Currently used as subclass for RZFetchedCollectionList
- * and RZArrayCollectionList.
+ *  Base class for providing common variables and
+ *  utils for classes implementing the RZCollectionList protocol.
  *
- * This class implements the protocol but requires subclasses
- * to override the protocol methods, or an exception will be
- * thrown.
+ *  Classes implementing the protocol are not required to use this
+ *  as a base class.
+ *
+ *  This class implements the protocol itself, but requires 
+ *  subclasses to override the protocol methods, or a runtime
+ *  exception will be thrown when an unimplemented method is
+ *  called.
  *
  ****************************************************************/
 

RZCollectionList/Classes/RZBaseCollectionList.m

@@ -178,7 +178,7 @@ - (void)cacheSectionNotificationWithSectionInfo:(id<RZCollectionListSectionInfo>
 - (void)sendWillChangeContentNotifications
 {
 #if kRZCollectionListNotificationsLogging
-    NSLog(@"RZFilteredCollectionList Will Change");
+    NSLog(@"%@ Will Change", self);
 #endif
     [[self.collectionListObservers allObjects] enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
         if ([obj conformsToProtocol:@protocol(RZCollectionListObserver)])
@@ -191,7 +191,7 @@ - (void)sendWillChangeContentNotifications
 - (void)sendDidChangeContentNotifications
 {
 #if kRZCollectionListNotificationsLogging
-    NSLog(@"RZFilteredCollectionList Did Change");
+    NSLog(@"%@ Did Change", self);
 #endif
     [[self.collectionListObservers allObjects] enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
         if ([obj conformsToProtocol:@protocol(RZCollectionListObserver)])
@@ -288,6 +288,9 @@ - (void)sendSectionNotifications:(NSArray *)sectionNotifications
         [[self.collectionListObservers allObjects] enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
             if ([obj conformsToProtocol:@protocol(RZCollectionListObserver)])
             {
+#if kRZCollectionListNotificationsLogging
+                NSLog(@"%@ Changed Section %@", self, notification);
+#endif
                 [obj collectionList:self didChangeSection:(id<RZCollectionListSectionInfo>)notification.sectionInfo atIndex:notification.sectionIndex forChangeType:notification.type];
             }
         }];
@@ -300,6 +303,9 @@ - (void)sendObjectNotifications:(NSArray *)objectNotifications
         [[self.collectionListObservers allObjects] enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
             if ([obj conformsToProtocol:@protocol(RZCollectionListObserver)])
             {
+#if kRZCollectionListNotificationsLogging
+                NSLog(@"%@ Changed Object %@", self, notification);
+#endif
                 [obj collectionList:self didChangeObject:notification.object atIndexPath:notification.indexPath forChangeType:notification.type newIndexPath:notification.nuIndexPath];
             }
         }];
@@ -353,6 +359,11 @@ - (NSArray*)sections
     @throw [self missingProtocolMethodExceptionWithSelector:_cmd];
 }
 
+- (NSArray*)cachedSections
+{
+    @throw [self missingProtocolMethodExceptionWithSelector:_cmd];
+}
+
 - (NSArray*)sectionIndexTitles
 {
     @throw [self missingProtocolMethodExceptionWithSelector:_cmd];

RZCollectionList/Classes/RZCollectionListProtocol.h

@@ -17,15 +17,26 @@
 @property (nonatomic, assign, readonly) NSUInteger numberOfObjects;
 @property (nonatomic, readonly) NSArray *objects;
 
+//! Return a copy of this object which returns STATIC values for all properties above
+/*!
+    This is different from NSCopying in the sense that a cachedCopy of section info
+    should not derive its property values from a dynamic source (source list, etc)
+    but rather should return a static value for each property.
+*/
+- (id<RZCollectionListSectionInfo>)cachedCopy;
+
 @end
 
 @protocol RZCollectionListDelegate;
 @protocol RZCollectionListObserver;
 
 @protocol RZCollectionList <NSObject>
 
+@required
+
 @property (nonatomic, readonly) NSArray *listObjects;
 @property (nonatomic, readonly) NSArray *sections;
+@property (nonatomic, readonly) NSArray *cachedSections; // sections cached prior to update, cleared when update is finished
 @property (nonatomic, readonly) NSArray *listObservers;
 @property (nonatomic, weak) id<RZCollectionListDelegate> delegate;