Clean up interfacing with internal editing/completed stores

AsyncDisplayKit/Details/ASCollectionDataController.mm

@@ -8,6 +8,7 @@
 
 #import "ASCollectionDataController.h"
 
+#import "ASLog.h"
 #import "ASAssert.h"
 #import "ASMultidimensionalArrayUtils.h"
 #import "ASDisplayNode.h"
@@ -21,17 +22,18 @@
 @end
 
 @implementation ASCollectionDataController {
-  NSMutableDictionary *_completedSupplementaryNodes;
-  NSMutableDictionary *_editingSupplementaryNodes;
-  
   NSMutableDictionary *_pendingNodes;
   NSMutableDictionary *_pendingIndexPaths;
 }
 
 - (void)prepareForReloadData
 {
+  _pendingNodes = [NSMutableDictionary dictionary];
+  _pendingIndexPaths = [NSMutableDictionary dictionary];
+
   NSArray *elementKinds = [self.collectionDataSource supplementaryNodeKindsInDataController:self];
   [elementKinds enumerateObjectsUsingBlock:^(NSString *kind, NSUInteger idx, BOOL * _Nonnull stop) {
+    ASLOG(@"Populating elements of kind: %@", kind);
     NSMutableArray *indexPaths = [NSMutableArray array];
     NSMutableArray *nodes = [NSMutableArray array];
     [self _populateSupplementaryNodesOfKind:kind withMutableNodes:nodes mutableIndexPaths:indexPaths];
@@ -43,9 +45,21 @@
 - (void)willReloadData
 {
   [_pendingNodes enumerateKeysAndObjectsUsingBlock:^(NSString *kind, NSMutableArray *nodes, BOOL *stop) {
+    ASLOG(@"Batch layout nodes of kind: %@, (%@)", kind, nodes);
+
+    // Insert each section
+    NSUInteger sectionCount = [self.collectionDataSource dataController:self numberOfSectionsForSupplementaryKind:kind];
+    NSMutableArray *sections = [NSMutableArray arrayWithCapacity:sectionCount];
+    for (int i = 0; i < sectionCount; i++) {
+      [sections addObject:[[NSMutableArray alloc] init]];
+    }
+    [self insertSections:sections ofKind:kind atIndexSet:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(0, sectionCount)] completion:nil];
+    
     [self batchLayoutNodes:nodes atIndexPaths:_pendingIndexPaths[kind] constrainedSize:^ASSizeRange(NSIndexPath *indexPath) {
       return [self.collectionDataSource dataController:self constrainedSizeForSupplementaryNodeOfKind:kind atIndexPath:indexPath];
-    } completion:nil];
+    } completion:^(NSArray *nodes, NSArray *indexPaths) {
+      [self insertNodes:nodes ofKind:kind atIndexPaths:indexPaths completion:nil];
+    }];
   }];
 }
 
@@ -66,7 +80,7 @@
 - (ASDisplayNode *)supplementaryNodeOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
 {
   ASDisplayNodeAssertMainThread();
-  return _completedSupplementaryNodes[kind][indexPath.section][indexPath.item];
+  return [self internalCompletedNodes][kind][indexPath.section][indexPath.item];
 }
 
 - (id<ASCollectionDataControllerSource>)collectionDataSource
@@ -74,37 +88,4 @@
   return (id<ASCollectionDataControllerSource>)self.dataSource;
 }
 
-#pragma mark - Internal Data Querying
-
-// TODO: Reduce code duplication by exposing generic insert/delete helpers from ASDataController
-- (void)_insertNodes:(NSArray *)nodes ofKind:(NSString *)kind atIndexPaths:(NSArray *)indexPaths
-{
-  if (indexPaths.count == 0)
-    return;
-  NSMutableArray *editingNodes = [self _editingNodesOfKind:kind];
-  ASInsertElementsIntoMultidimensionalArrayAtIndexPaths(editingNodes, indexPaths, nodes);
-  NSMutableArray *completedNodes = (NSMutableArray *)ASMultidimensionalArrayDeepMutableCopy(editingNodes);
-  ASDisplayNodePerformBlockOnMainThread(^{
-    _completedSupplementaryNodes[kind] = completedNodes;
-    // TODO: Notify change
-  });
-}
-
-// TODO: Reduce code duplication by exposing generic insert/delete helpers from ASDataController
-- (void)_deleteNodesOfKind:(NSString *)kind atIndexPaths:(NSArray *)indexPaths
-{
-  if (indexPaths.count == 0)
-    return;
-}
-
-- (NSMutableArray *)_completedNodesOfKind:(NSString *)kind
-{
-  return _completedSupplementaryNodes[kind];
-}
-
-- (NSMutableArray *)_editingNodesOfKind:(NSString *)kind
-{
-  return _editingSupplementaryNodes[kind];
-}
-
 @end

AsyncDisplayKit/Details/ASCollectionViewFlowLayoutInspector.m

@@ -42,7 +42,11 @@
 
 - (NSUInteger)collectionView:(ASCollectionView *)collectionView numberOfSectionsForSupplementaryKind:(NSString *)kind
 {
-  return [collectionView.asyncDataSource numberOfSectionsInCollectionView:collectionView];
+  if ([collectionView.asyncDataSource respondsToSelector:@selector(numberOfSectionsInCollectionView:)]) {
+    return [collectionView.asyncDataSource numberOfSectionsInCollectionView:collectionView];
+  } else {
+    return 1;
+  }
 }
 
 - (NSUInteger)collectionView:(ASCollectionView *)collectionView supplementaryViewsOfKind:(NSString *)kind inSection:(NSUInteger)section

AsyncDisplayKit/Details/ASDataController+Subclasses.h

@@ -25,11 +25,6 @@
  */
 - (void)accessDataSourceWithBlock:(dispatch_block_t)block;
 
-/**
- * Measure and layout the given nodes in optimized batches, constraining each to a given size.
- */
-- (void)batchLayoutNodes:(NSArray *)nodes atIndexPaths:(NSArray *)indexPaths constrainedSize:(ASSizeRange (^)(NSIndexPath *indexPath))constraintedSizeBlock completion:(void (^)(NSArray *nodes, NSArray *indexPaths))completionBlock;
-
 /**
  * An opportunity for a subclass to access the data source before entering into the editing queue
  */
@@ -40,4 +35,19 @@
  */
 - (void)willReloadData;
 
+- (NSMutableDictionary *)internalCompletedNodes;
+
+/**
+ * Measure and layout the given nodes in optimized batches, constraining each to a given size.
+ */
+- (void)batchLayoutNodes:(NSArray *)nodes atIndexPaths:(NSArray *)indexPaths constrainedSize:(ASSizeRange (^)(NSIndexPath *indexPath))constraintedSizeBlock completion:(void (^)(NSArray *nodes, NSArray *indexPaths))completionBlock;
+
+- (void)insertNodes:(NSArray *)nodes ofKind:(NSString *)kind atIndexPaths:(NSArray *)indexPaths completion:(void (^)(NSArray *nodes, NSArray *indexPaths))completionBlock;
+
+- (void)deleteNodesOfKind:(NSString *)kind atIndexPaths:(NSArray *)indexPaths completion:(void (^)(NSArray *nodes, NSArray *indexPaths))completionBlock;
+
+- (void)insertSections:(NSMutableArray *)sections ofKind:(NSString *)kind atIndexSet:(NSIndexSet *)indexSet completion:(void (^)(NSArray *sections, NSIndexSet *indexSet))completionBlock;
+
+- (void)deleteSectionsOfKind:(NSString *)kind atIndexSet:(NSIndexSet *)indexSet completion:(void (^)(NSIndexSet *indexSet))completionBlock;
+
 @end

AsyncDisplayKit/Details/ASDataController.mm

@@ -19,12 +19,16 @@
 
 const static NSUInteger kASDataControllerSizingCountPerProcessor = 5;
 
+NSString * const ASRowNodeKind = @"_ASRowNodeKind";
+
 static void *kASSizingQueueContext = &kASSizingQueueContext;
 
 @interface ASDataController () {
   NSMutableArray *_externalCompletedNodes;    // Main thread only.  External data access can immediately query this if available.
-  NSMutableArray *_completedNodes;            // Main thread only.  External data access can immediately query this if _externalCompletedNodes is unavailable.
+  NSMutableDictionary *_completedNodes;       // Main thread only.  External data access can immediately query this if _externalCompletedNodes is unavailable.
-  NSMutableArray *_editingNodes;              // Modified on _editingTransactionQueue only.  Updates propogated to _completedNodes.
+  NSMutableDictionary *_editingNodes;         // Modified on _editingTransactionQueue only.  Updates propogated to _completedNodes.
+  
+  
   
   NSMutableArray *_pendingEditCommandBlocks;  // To be run on the main thread.  Handles begin/endUpdates tracking.
   NSOperationQueue *_editingTransactionQueue; // Serial background queue.  Dispatches concurrent layout and manages _editingNodes.
@@ -50,9 +54,12 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
     return nil;
   }
   
-  _completedNodes = [NSMutableArray array];
+  _completedNodes = [NSMutableDictionary dictionary];
-  _editingNodes = [NSMutableArray array];
+  _editingNodes = [NSMutableDictionary dictionary];
 
+  _completedNodes[ASRowNodeKind] = [NSMutableArray array];
+  _editingNodes[ASRowNodeKind] = [NSMutableArray array];
+  
   _pendingEditCommandBlocks = [NSMutableArray array];
   
   _editingTransactionQueue = [[NSOperationQueue alloc] init];
@@ -178,7 +185,78 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
   dispatch_group_wait(layoutGroup, DISPATCH_TIME_FOREVER);
   free(nodeBoundSizes);
 
-  completionBlock(nodes, indexPaths);
+  if (completionBlock)
+    completionBlock(nodes, indexPaths);
+}
+
+#pragma mark - External Data Querying + Editing
+
+- (void)insertNodes:(NSArray *)nodes ofKind:(NSString *)kind atIndexPaths:(NSArray *)indexPaths completion:(void (^)(NSArray *nodes, NSArray *indexPaths))completionBlock
+{
+  if (indexPaths.count == 0)
+    return;
+  
+  NSMutableArray *editingNodes = _editingNodes[kind];
+  ASInsertElementsIntoMultidimensionalArrayAtIndexPaths(editingNodes, indexPaths, nodes);
+  _editingNodes[kind] = editingNodes;
+  
+  // Deep copy is critical here, or future edits to the sub-arrays will pollute state between _editing and _complete on different threads.
+  NSMutableArray *completedNodes = (NSMutableArray *)ASMultidimensionalArrayDeepMutableCopy(editingNodes);
+  
+  ASDisplayNodePerformBlockOnMainThread(^{
+    _completedNodes[kind] = completedNodes;
+    if (completionBlock) {
+      completionBlock(nodes, indexPaths);
+    }
+  });
+}
+
+- (void)deleteNodesOfKind:(NSString *)kind atIndexPaths:(NSArray *)indexPaths completion:(void (^)(NSArray *nodes, NSArray *indexPaths))completionBlock
+{
+  if (indexPaths.count == 0)
+    return;
+  ASLOG(@"_deleteNodesAtIndexPaths:%@ ofKind:%@, full index paths in _editingNodes = %@", indexPaths, kind, ASIndexPathsForMultidimensionalArray(_editingNodes[kind]));
+  NSMutableArray *editingNodes = _editingNodes[kind];
+  ASDeleteElementsInMultidimensionalArrayAtIndexPaths(editingNodes, indexPaths);
+  _editingNodes[kind] = editingNodes;
+
+  ASDisplayNodePerformBlockOnMainThread(^{
+    NSArray *nodes = ASFindElementsInMultidimensionalArrayAtIndexPaths(_completedNodes[kind], indexPaths);
+    ASDeleteElementsInMultidimensionalArrayAtIndexPaths(_completedNodes[kind], indexPaths);
+    if (completionBlock) {
+      completionBlock(nodes, indexPaths);
+    }
+  });
+}
+
+- (void)insertSections:(NSMutableArray *)sections ofKind:(NSString *)kind atIndexSet:(NSIndexSet *)indexSet completion:(void (^)(NSArray *sections, NSIndexSet *indexSet))completionBlock
+{
+  if (indexSet.count == 0)
+    return;
+  [_editingNodes[kind] insertObjects:sections atIndexes:indexSet];
+  
+  // Deep copy is critical here, or future edits to the sub-arrays will pollute state between _editing and _complete on different threads.
+  NSArray *sectionsForCompleted = (NSMutableArray *)ASMultidimensionalArrayDeepMutableCopy(sections);
+  
+  ASDisplayNodePerformBlockOnMainThread(^{
+    [_completedNodes[kind] insertObjects:sectionsForCompleted atIndexes:indexSet];
+    if (completionBlock) {
+      completionBlock(sections, indexSet);
+    }
+  });
+}
+
+- (void)deleteSectionsOfKind:(NSString *)kind atIndexSet:(NSIndexSet *)indexSet completion:(void (^)(NSIndexSet *indexSet))completionBlock
+{
+  if (indexSet.count == 0)
+    return;
+  [_editingNodes[kind] removeObjectsAtIndexes:indexSet];
+  ASDisplayNodePerformBlockOnMainThread(^{
+    [_completedNodes[kind] removeObjectsAtIndexes:indexSet];
+    if (completionBlock) {
+      completionBlock(indexSet);
+    }
+  });
 }
 
 #pragma mark - Internal Data Querying + Editing
@@ -191,18 +269,10 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
  */
 - (void)_insertNodes:(NSArray *)nodes atIndexPaths:(NSArray *)indexPaths withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions
 {
-  if (indexPaths.count == 0)
+  [self insertNodes:nodes ofKind:ASRowNodeKind atIndexPaths:indexPaths completion:^(NSArray *nodes, NSArray *indexPaths) {
-    return;
-  ASInsertElementsIntoMultidimensionalArrayAtIndexPaths(_editingNodes, indexPaths, nodes);
-  
-  // Deep copy is critical here, or future edits to the sub-arrays will pollute state between _editing and _complete on different threads.
-  NSMutableArray *completedNodes = (NSMutableArray *)ASMultidimensionalArrayDeepMutableCopy(_editingNodes);
-  
-  ASDisplayNodePerformBlockOnMainThread(^{
-    _completedNodes = completedNodes;
     if (_delegateDidInsertNodes)
       [_delegate dataController:self didInsertNodes:nodes atIndexPaths:indexPaths withAnimationOptions:animationOptions];
-  });
+  }];
 }
 
 /**
@@ -213,17 +283,10 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
  */
 - (void)_deleteNodesAtIndexPaths:(NSArray *)indexPaths withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions
 {
-  if (indexPaths.count == 0)
+  [self deleteNodesOfKind:ASRowNodeKind atIndexPaths:indexPaths completion:^(NSArray *nodes, NSArray *indexPaths) {
-    return;
-  ASLOG(@"_deleteNodesAtIndexPaths:%@, full index paths in _editingNodes = %@", indexPaths, ASIndexPathsForMultidimensionalArray(_editingNodes));
-  ASDeleteElementsInMultidimensionalArrayAtIndexPaths(_editingNodes, indexPaths);
-
-  ASDisplayNodePerformBlockOnMainThread(^{
-    NSArray *nodes = ASFindElementsInMultidimensionalArrayAtIndexPaths(_completedNodes, indexPaths);
-    ASDeleteElementsInMultidimensionalArrayAtIndexPaths(_completedNodes, indexPaths);
     if (_delegateDidDeleteNodes)
       [_delegate dataController:self didDeleteNodes:nodes atIndexPaths:indexPaths withAnimationOptions:animationOptions];
-  });
+  }];
 }
 
 /**
@@ -234,18 +297,10 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
  */
 - (void)_insertSections:(NSMutableArray *)sections atIndexSet:(NSIndexSet *)indexSet withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions
 {
-  if (indexSet.count == 0)
+  [self insertSections:sections ofKind:ASRowNodeKind atIndexSet:indexSet completion:^(NSArray *sections, NSIndexSet *indexSet) {
-    return;
-  [_editingNodes insertObjects:sections atIndexes:indexSet];
-  
-  // Deep copy is critical here, or future edits to the sub-arrays will pollute state between _editing and _complete on different threads.
-  NSArray *sectionsForCompleted = (NSMutableArray *)ASMultidimensionalArrayDeepMutableCopy(sections);
-  
-  ASDisplayNodePerformBlockOnMainThread(^{
-    [_completedNodes insertObjects:sectionsForCompleted atIndexes:indexSet];
     if (_delegateDidInsertSections)
       [_delegate dataController:self didInsertSections:sections atIndexSet:indexSet withAnimationOptions:animationOptions];
-  });
+  }];
 }
 
 /**
@@ -256,14 +311,10 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
  */
 - (void)_deleteSectionsAtIndexSet:(NSIndexSet *)indexSet withAnimationOptions:(ASDataControllerAnimationOptions)animationOptions
 {
-  if (indexSet.count == 0)
+  [self deleteSectionsOfKind:ASRowNodeKind atIndexSet:indexSet completion:^(NSIndexSet *indexSet) {
-    return;
-  [_editingNodes removeObjectsAtIndexes:indexSet];
-  ASDisplayNodePerformBlockOnMainThread(^{
-    [_completedNodes removeObjectsAtIndexes:indexSet];
     if (_delegateDidDeleteSections)
       [_delegate dataController:self didDeleteSectionsAtIndexSet:indexSet withAnimationOptions:animationOptions];
-  });
+  }];
 }
 
 #pragma mark - Initial Load & Full Reload (External API)
@@ -316,7 +367,7 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
         ASLOG(@"Edit Transaction - reloadData");
         
         // Remove everything that existed before the reload, now that we're ready to insert replacements
-        NSArray *indexPaths = ASIndexPathsForMultidimensionalArray(_editingNodes);
+        NSArray *indexPaths = ASIndexPathsForMultidimensionalArray(_editingNodes[ASRowNodeKind]);
         [self _deleteNodesAtIndexPaths:indexPaths withAnimationOptions:animationOptions];
         
         NSMutableIndexSet *indexSet = [[NSMutableIndexSet alloc] initWithIndexesInRange:NSMakeRange(0, _editingNodes.count)];
@@ -435,7 +486,7 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
       ASDisplayNodePerformBlockOnMainThread(^{
         // Deep copy _completedNodes to _externalCompletedNodes.
         // Any external queries from now on will be done on _externalCompletedNodes, to guarantee data consistency with the delegate.
-        _externalCompletedNodes = (NSMutableArray *)ASMultidimensionalArrayDeepMutableCopy(_completedNodes);
+        _externalCompletedNodes = (NSMutableArray *)ASMultidimensionalArrayDeepMutableCopy(_completedNodes[ASRowNodeKind]);
 
         ASLOG(@"endUpdatesWithCompletion - begin updates call to delegate");
         [_delegate dataControllerBeginUpdates:self];
@@ -515,7 +566,7 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
     [_editingTransactionQueue addOperationWithBlock:^{
       // remove elements
       ASLOG(@"Edit Transaction - deleteSections: %@", indexSet);
-      NSArray *indexPaths = ASIndexPathsForMultidimensionalArrayAtIndexSet(_editingNodes, indexSet);
+      NSArray *indexPaths = ASIndexPathsForMultidimensionalArrayAtIndexSet(_editingNodes[ASRowNodeKind], indexSet);
       
       [self _deleteNodesAtIndexPaths:indexPaths withAnimationOptions:animationOptions];
       [self _deleteSectionsAtIndexSet:indexSet withAnimationOptions:animationOptions];
@@ -544,9 +595,9 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
       [self _layoutNodesWithMainThreadAffinity:updatedNodes atIndexPaths:updatedIndexPaths];
       
       [_editingTransactionQueue addOperationWithBlock:^{
-        NSArray *indexPaths = ASIndexPathsForMultidimensionalArrayAtIndexSet(_editingNodes, sections);
+        NSArray *indexPaths = ASIndexPathsForMultidimensionalArrayAtIndexSet(_editingNodes[ASRowNodeKind], sections);
         
-        ASLOG(@"Edit Transaction - reloadSections: updatedIndexPaths: %@, indexPaths: %@, _editingNodes: %@", updatedIndexPaths, indexPaths, ASIndexPathsForMultidimensionalArray(_editingNodes));
+        ASLOG(@"Edit Transaction - reloadSections: updatedIndexPaths: %@, indexPaths: %@, _editingNodes: %@", updatedIndexPaths, indexPaths, ASIndexPathsForMultidimensionalArray(_editingNodes[ASRowNodeKind]));
         
         [self _deleteNodesAtIndexPaths:indexPaths withAnimationOptions:animationOptions];
         
@@ -570,8 +621,8 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
       
       ASLOG(@"Edit Transaction - moveSection");
       
-      NSArray *indexPaths = ASIndexPathsForMultidimensionalArrayAtIndexSet(_editingNodes, [NSIndexSet indexSetWithIndex:section]);
+      NSArray *indexPaths = ASIndexPathsForMultidimensionalArrayAtIndexSet(_editingNodes[ASRowNodeKind], [NSIndexSet indexSetWithIndex:section]);
-      NSArray *nodes = ASFindElementsInMultidimensionalArrayAtIndexPaths(_editingNodes, indexPaths);
+      NSArray *nodes = ASFindElementsInMultidimensionalArrayAtIndexPaths(_editingNodes[ASRowNodeKind], indexPaths);
       [self _deleteNodesAtIndexPaths:indexPaths withAnimationOptions:animationOptions];
 
       // update the section of indexpaths
@@ -696,7 +747,7 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
     // (see _layoutNodes:atIndexPaths:withAnimationOptions:).
     [_editingTransactionQueue addOperationWithBlock:^{
       ASDisplayNodePerformBlockOnMainThread(^{
-        relayoutNodesBlock(_completedNodes);
+        relayoutNodesBlock(_completedNodes[ASRowNodeKind]);
       });
     }];
   }];
@@ -711,7 +762,7 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
     
     [_editingTransactionQueue addOperationWithBlock:^{
       ASLOG(@"Edit Transaction - moveRow: %@ > %@", indexPath, newIndexPath);
-      NSArray *nodes = ASFindElementsInMultidimensionalArrayAtIndexPaths(_editingNodes, [NSArray arrayWithObject:indexPath]);
+      NSArray *nodes = ASFindElementsInMultidimensionalArrayAtIndexPaths(_editingNodes[ASRowNodeKind], [NSArray arrayWithObject:indexPath]);
       NSArray *indexPaths = [NSArray arrayWithObject:indexPath];
       [self _deleteNodesAtIndexPaths:indexPaths withAnimationOptions:animationOptions];
 
@@ -722,6 +773,13 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
   }];
 }
 
+#pragma mark - Data Querying (Subclass API)
+
+- (NSMutableDictionary *)internalCompletedNodes
+{
+  return _completedNodes;
+}
+
 #pragma mark - Data Querying (External API)
 
 - (NSUInteger)numberOfSections
@@ -771,7 +829,7 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
 - (NSArray *)completedNodes
 {
   ASDisplayNodeAssertMainThread();
-  return _externalCompletedNodes != nil ? _externalCompletedNodes : _completedNodes;
+  return _externalCompletedNodes != nil ? _externalCompletedNodes : _completedNodes[ASRowNodeKind];
 }
 
 #pragma mark - Dealloc
@@ -779,15 +837,17 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
 - (void)dealloc
 {
   ASDisplayNodeAssertMainThread();
-  [_completedNodes enumerateObjectsUsingBlock:^(NSMutableArray *section, NSUInteger sectionIndex, BOOL *stop) {
+  [_completedNodes enumerateKeysAndObjectsUsingBlock:^(NSString *kind, NSMutableArray *nodes, BOOL * _Nonnull stop) {
-    [section enumerateObjectsUsingBlock:^(ASCellNode *node, NSUInteger rowIndex, BOOL *stop) {
+    [nodes enumerateObjectsUsingBlock:^(NSMutableArray *section, NSUInteger sectionIndex, BOOL *stop) {
-      if (node.isNodeLoaded) {
+      [section enumerateObjectsUsingBlock:^(ASDisplayNode *node, NSUInteger rowIndex, BOOL *stop) {
-        if (node.layerBacked) {
+        if (node.isNodeLoaded) {
-          [node.layer removeFromSuperlayer];
+          if (node.layerBacked) {
-        } else {
+            [node.layer removeFromSuperlayer];
-          [node.view removeFromSuperview];
+          } else {
+            [node.view removeFromSuperview];
+          }
         }
-      }
+      }];
     }];
   }];
 }

AsyncDisplayKit/Details/ASRangeController.mm

@@ -158,9 +158,9 @@
   return rangeType == ASLayoutRangeTypeRender;
 }
 
-- (void)configureContentView:(UIView *)contentView forNode:(ASDisplayNode *)cellNode
+- (void)configureContentView:(UIView *)contentView forNode:(ASDisplayNode *)node
 {
-  if (cellNode.view.superview == contentView) {
+  if (node.view.superview == contentView) {
     // this content view is already correctly configured
     return;
   }
@@ -170,7 +170,7 @@
     [view removeFromSuperview];
   }
 
-  [self moveNode:cellNode toView:contentView];
+  [self moveNode:node toView:contentView];
 }
 
 

examples/ASCollectionView/Sample/ViewController.m

@@ -33,6 +33,7 @@
   
   UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
   layout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
+  layout.headerReferenceSize = CGSizeMake(50.0, 50.0);
   
   _collectionView = [[ASCollectionView alloc] initWithFrame:CGRectZero collectionViewLayout:layout asyncDataFetching:YES];
   _collectionView.asyncDataSource = self;