Support for updating an AutoView's sorting block without updating it's grouping block

Testing/UnitTesting/TestYapDatabaseView.m

@@ -2844,6 +2844,25 @@ - (void)testChangeBlocks_nonPersistent
 	[self _testChangeBlocks_withPath:databasePath options:options];
 }
 
+- (void)testChangeSortBlock_persistent
+{
+	NSString *databasePath = [self databasePath:NSStringFromSelector(_cmd)];
+
+	YapDatabaseViewOptions *options = [[YapDatabaseViewOptions alloc] init];
+	options.isPersistent = YES;
+
+	[self _testChangeSortBlock_withPath:databasePath options:options];
+}
+- (void)testChangeSortBlock_nonPersistent
+{
+	NSString *databasePath = [self databasePath:NSStringFromSelector(_cmd)];
+
+	YapDatabaseViewOptions *options = [[YapDatabaseViewOptions alloc] init];
+	options.isPersistent = NO;
+
+	[self _testChangeSortBlock_withPath:databasePath options:options];
+}
+
 - (void)_testChangeBlocks_withPath:(NSString *)databasePath options:(YapDatabaseViewOptions *)options
 {
 	[[NSFileManager defaultManager] removeItemAtPath:databasePath error:NULL];
@@ -2950,6 +2969,111 @@ - (void)_testChangeBlocks_withPath:(NSString *)databasePath options:(YapDatabase
 	XCTAssertTrue([rowChanges count] == 10, @"Bad count");
 }
 
+- (void)_testChangeSortBlock_withPath:(NSString *)databasePath options:(YapDatabaseViewOptions *)options
+{
+	[[NSFileManager defaultManager] removeItemAtPath:databasePath error:NULL];
+	YapDatabase *database = [[YapDatabase alloc] initWithPath:databasePath];
+
+	XCTAssertNotNil(database, @"Oops");
+
+	YapDatabaseConnection *connection1 = [database newConnection];
+	YapDatabaseConnection *connection2 = [database newConnection];
+
+	YapDatabaseViewGrouping *grouping = [YapDatabaseViewGrouping withObjectBlock:
+		^NSString *(YapDatabaseReadTransaction *transaction, NSString *collection, NSString *key, id obj)
+	{
+	 __unsafe_unretained NSNumber *number = (NSNumber *)obj;
+
+	 if ([number intValue] % 2 == 0)
+		 return @"";
+	 else
+		 return nil;
+	}];
+
+	YapDatabaseViewSorting *sorting = [YapDatabaseViewSorting withObjectBlock:
+		^(YapDatabaseReadTransaction *transaction, NSString *group,
+			NSString *collection1, NSString *key1, id obj1,
+			NSString *collection2, NSString *key2, id obj2)
+	{
+		__unsafe_unretained NSNumber *number1 = (NSNumber *)obj1;
+		__unsafe_unretained NSNumber *number2 = (NSNumber *)obj2;
+
+		return [number1 compare:number2];
+	}];
+
+	YapDatabaseAutoView *databaseView =
+	[[YapDatabaseAutoView alloc] initWithGrouping:grouping
+	                                      sorting:sorting
+	                                   versionTag:@"1"
+	                                      options:options];
+
+	BOOL registerResult = [database registerExtension:databaseView withName:@"order"];
+
+	XCTAssertTrue(registerResult, @"Failure registering extension");
+
+	// Add a bunch of values to the database & to the view
+
+	NSUInteger count = 10;
+
+	[connection1 readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+
+		for (int i = 0; i < count; i++)
+		{
+			NSString *key = [NSString stringWithFormat:@"key-%d", i];
+			NSNumber *num = [NSNumber numberWithInt:i];
+
+			[transaction setObject:num forKey:key inCollection:nil];
+		}
+	}];
+
+	// Make sure the view is populated
+
+	[connection1 readWithBlock:^(YapDatabaseReadTransaction *transaction) {
+
+		XCTAssertTrue([[transaction ext:@"order"] numberOfItemsInGroup:@""] == 5, @"View count is wrong");
+	}];
+
+	// Now change the groupingBlock
+
+	YapDatabaseViewMappings *mappings = [YapDatabaseViewMappings mappingsWithGroups:@[ @"" ] view:@"order"];
+
+	[connection2 beginLongLivedReadTransaction];
+	[connection2 readWithBlock:^(YapDatabaseReadTransaction *transaction) {
+
+		[mappings updateWithTransaction:transaction];
+	}];
+
+	YapDatabaseViewSorting *newSorting = [YapDatabaseViewSorting withObjectBlock:
+		^(YapDatabaseReadTransaction *transaction, NSString *group,
+			NSString *collection1, NSString *key1, id obj1,
+			NSString *collection2, NSString *key2, id obj2)
+	{
+		__unsafe_unretained NSNumber *number1 = (NSNumber *)obj1;
+		__unsafe_unretained NSNumber *number2 = (NSNumber *)obj2;
+
+		return [number2 compare:number1];
+	}];
+
+	[connection1 readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
+
+		[[transaction ext:@"order"] setSorting:newSorting
+		                            versionTag:@"2"];
+	}];
+
+	NSArray *notifications =[connection2 beginLongLivedReadTransaction];
+
+	NSArray *sectionChanges = nil;
+	NSArray *rowChanges = nil;
+
+	[[connection2 ext:@"order"] getSectionChanges:&sectionChanges
+	                                   rowChanges:&rowChanges
+	                             forNotifications:notifications
+	                                 withMappings:mappings];
+
+	XCTAssertTrue([sectionChanges count] == 0, @"Bad count");
+	XCTAssertTrue([rowChanges count] == 5, @"Bad count");
+}
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 #pragma mark -
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

YapDatabase/Extensions/AutoView/Internal/YapDatabaseAutoViewPrivate.h

@@ -85,6 +85,9 @@
             sorting:(YapDatabaseViewSorting *)newSorting
          versionTag:(NSString *)newVersionTag;
 
+- (void)setSorting:(YapDatabaseViewSorting *)newSorting
+        versionTag:(NSString *)newVersionTag;
+
 @end
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

YapDatabase/Extensions/AutoView/YapDatabaseAutoViewConnection.m

@@ -175,6 +175,16 @@ - (void)setGrouping:(YapDatabaseViewGrouping *)newGrouping
 	versionTagChanged = YES;
 }
 
+- (void)setSorting:(YapDatabaseViewSorting *)newSorting
+        versionTag:(NSString *)newVersionTag
+{
+	sorting = newSorting;
+	sortingChanged = YES;
+
+	versionTag = newVersionTag;
+	versionTagChanged = YES;
+}
+
 - (void)getGrouping:(YapDatabaseViewGrouping **)groupingPtr
             sorting:(YapDatabaseViewSorting **)sortingPtr
 {

YapDatabase/Extensions/AutoView/YapDatabaseAutoViewTransaction.h

@@ -164,6 +164,15 @@ NS_ASSUME_NONNULL_BEGIN
             sorting:(YapDatabaseViewSorting *)sorting
          versionTag:(nullable NSString *)versionTag;
 
+/**
+ * This method allows you to change the sorting on-the-fly.
+ *
+ * Note: You must pass a different versionTag, or this method does nothing.
+ * If needed, you can fetch the current versionTag via the [viewTransaction versionTag] method.
+ **/
+- (void)setSorting:(YapDatabaseViewSorting *)sorting
+        versionTag:(nullable NSString *)versionTag;
+
 @end
 
 NS_ASSUME_NONNULL_END