Refactoring Part 3: Feed configuration and CoreData Model

README.md

@@ -73,10 +73,10 @@ ToDo
 		- [x] Delete old ones eventually
 		- [x] Pause on internet connection lost
 	- [ ] Download with ephemeral url session?
-	- [ ] Purge cache
+	- [x] Purge cache
-		- [ ] Manually or automatically
+		- [x] Manually or automatically
-		- [ ] Add something to restore a broken state
+		- [x] Add something to restore a broken state
-	- [ ] Code Documentation (mostly methods)
+	- [x] Code Documentation (mostly methods)
 	- [ ] Add Sandboxing
 		- [ ] Disable Startup checkbox (or other workaround)
 

baRSS.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		540F704521B6C16C0022E69D /* FeedMeta+Ext.m in Sources */ = {isa = PBXBuildFile; fileRef = 540F704421B6C16C0022E69D /* FeedMeta+Ext.m */; };
 		54195883218A061100581B79 /* Feed+Ext.m in Sources */ = {isa = PBXBuildFile; fileRef = 54195882218A061100581B79 /* Feed+Ext.m */; };
 		54195886218E1BDB00581B79 /* NSMenu+Ext.m in Sources */ = {isa = PBXBuildFile; fileRef = 54195885218E1BDB00581B79 /* NSMenu+Ext.m */; };
 		54209E942117325100F3B5EF /* DrawImage.m in Sources */ = {isa = PBXBuildFile; fileRef = 54209E932117325100F3B5EF /* DrawImage.m */; };
@@ -21,7 +22,7 @@
 		546FC44321189975007CC3A3 /* SettingsGeneral.m in Sources */ = {isa = PBXBuildFile; fileRef = 546FC44121189975007CC3A3 /* SettingsGeneral.m */; };
 		546FC44421189975007CC3A3 /* SettingsGeneral.xib in Resources */ = {isa = PBXBuildFile; fileRef = 546FC44221189975007CC3A3 /* SettingsGeneral.xib */; };
 		546FC4472118A8E6007CC3A3 /* Preferences.xib in Resources */ = {isa = PBXBuildFile; fileRef = 546FC4462118A8E6007CC3A3 /* Preferences.xib */; };
-		5477D34E21233C62002BA27F /* FeedConfig+Ext.m in Sources */ = {isa = PBXBuildFile; fileRef = 5477D34D21233C62002BA27F /* FeedConfig+Ext.m */; };
+		5477D34E21233C62002BA27F /* FeedGroup+Ext.m in Sources */ = {isa = PBXBuildFile; fileRef = 5477D34D21233C62002BA27F /* FeedGroup+Ext.m */; };
 		5496B511214D6275003ED4ED /* UserPrefs.m in Sources */ = {isa = PBXBuildFile; fileRef = 5496B510214D6275003ED4ED /* UserPrefs.m */; };
 		54ACC28621061B3C0020715F /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 54ACC28521061B3C0020715F /* Assets.xcassets */; };
 		54ACC28C21061B3C0020715F /* main.m in Sources */ = {isa = PBXBuildFile; fileRef = 54ACC28B21061B3C0020715F /* main.m */; };
@@ -72,6 +73,8 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		540F704321B6C16C0022E69D /* FeedMeta+Ext.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "FeedMeta+Ext.h"; sourceTree = "<group>"; };
+		540F704421B6C16C0022E69D /* FeedMeta+Ext.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "FeedMeta+Ext.m"; sourceTree = "<group>"; };
 		54195881218A061100581B79 /* Feed+Ext.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "Feed+Ext.h"; sourceTree = "<group>"; };
 		54195882218A061100581B79 /* Feed+Ext.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "Feed+Ext.m"; sourceTree = "<group>"; };
 		54195884218E1BDB00581B79 /* NSMenu+Ext.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "NSMenu+Ext.h"; sourceTree = "<group>"; };
@@ -94,8 +97,8 @@
 		546FC44121189975007CC3A3 /* SettingsGeneral.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SettingsGeneral.m; sourceTree = "<group>"; };
 		546FC44221189975007CC3A3 /* SettingsGeneral.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = SettingsGeneral.xib; sourceTree = "<group>"; };
 		546FC4462118A8E6007CC3A3 /* Preferences.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = Preferences.xib; sourceTree = "<group>"; };
-		5477D34C21233C62002BA27F /* FeedConfig+Ext.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "FeedConfig+Ext.h"; sourceTree = "<group>"; };
+		5477D34C21233C62002BA27F /* FeedGroup+Ext.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "FeedGroup+Ext.h"; sourceTree = "<group>"; };
-		5477D34D21233C62002BA27F /* FeedConfig+Ext.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "FeedConfig+Ext.m"; sourceTree = "<group>"; };
+		5477D34D21233C62002BA27F /* FeedGroup+Ext.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "FeedGroup+Ext.m"; sourceTree = "<group>"; };
 		5496B50F214D6275003ED4ED /* UserPrefs.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = UserPrefs.h; sourceTree = "<group>"; };
 		5496B510214D6275003ED4ED /* UserPrefs.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = UserPrefs.m; sourceTree = "<group>"; };
 		54ACC27C21061B3B0020715F /* baRSS.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = baRSS.app; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -143,10 +146,12 @@
 		54195880218A05E700581B79 /* Categories */ = {
 			isa = PBXGroup;
 			children = (
-				5477D34C21233C62002BA27F /* FeedConfig+Ext.h */,
+				5477D34C21233C62002BA27F /* FeedGroup+Ext.h */,
-				5477D34D21233C62002BA27F /* FeedConfig+Ext.m */,
+				5477D34D21233C62002BA27F /* FeedGroup+Ext.m */,
 				54195881218A061100581B79 /* Feed+Ext.h */,
 				54195882218A061100581B79 /* Feed+Ext.m */,
+				540F704321B6C16C0022E69D /* FeedMeta+Ext.h */,
+				540F704421B6C16C0022E69D /* FeedMeta+Ext.m */,
 			);
 			path = Categories;
 			sourceTree = "<group>";
@@ -386,7 +391,8 @@
 				544B011D2114EE9100386E5C /* AppHook.m in Sources */,
 				546FC44321189975007CC3A3 /* SettingsGeneral.m in Sources */,
 				54ACC29521061E270020715F /* FeedDownload.m in Sources */,
-				5477D34E21233C62002BA27F /* FeedConfig+Ext.m in Sources */,
+				5477D34E21233C62002BA27F /* FeedGroup+Ext.m in Sources */,
+				540F704521B6C16C0022E69D /* FeedMeta+Ext.m in Sources */,
 				54ACC28C21061B3C0020715F /* main.m in Sources */,
 				54FE73D3212316CD003EAC65 /* BarMenu.m in Sources */,
 				544B011A2114B41200386E5C /* ModalSheet.m in Sources */,

baRSS/Categories/Feed+Ext.h

@@ -25,9 +25,12 @@
 @class RSParsedFeed;
 
 @interface Feed (Ext)
-- (void)updateWithRSS:(RSParsedFeed*)obj;
+// Generator methods / Feed update
-- (NSArray<FeedItem*>*)sortedArticles;
++ (instancetype)newFeedAndMetaInContext:(NSManagedObjectContext*)context;
-
+- (void)calculateAndSetIndexPathString;
+- (void)updateWithRSS:(RSParsedFeed*)obj postUnreadCountChange:(BOOL)flag;
+// Article properties
+- (NSArray<FeedArticle*>*)sortedArticles;
 - (int)markAllItemsRead;
 - (int)markAllItemsUnread;
 @end

baRSS/Categories/Feed+Ext.m

@@ -21,23 +21,48 @@
 //  SOFTWARE.
 
 #import "Feed+Ext.h"
-#import "FeedConfig+Ext.h"
+#import "FeedMeta+Ext.h"
-#import "FeedItem+CoreDataClass.h"
+#import "FeedGroup+Ext.h"
+#import "FeedArticle+CoreDataClass.h"
+#import "Constants.h"
+
 #import <RSXML/RSXML.h>
 
 @implementation Feed (Ext)
 
+/// Instantiates new @c Feed and @c FeedMeta entities in context.
++ (instancetype)newFeedAndMetaInContext:(NSManagedObjectContext*)moc {
+	Feed *feed = [[Feed alloc] initWithEntity:Feed.entity insertIntoManagedObjectContext:moc];
+	feed.meta = [[FeedMeta alloc] initWithEntity:FeedMeta.entity insertIntoManagedObjectContext:moc];
+	return feed;
+}
+
+/// Call @c indexPathString on @c .group and update @c .indexPath if current value is different.
+- (void)calculateAndSetIndexPathString {
+	NSString *pthStr = [self.group indexPathString];
+	if (![self.indexPath isEqualToString:pthStr])
+		self.indexPath = pthStr;
+}
+
+#pragma mark - Update Feed Items -
+
 /**
  Replace feed title, subtitle and link (if changed). Also adds new articles and removes old ones.
  */
-- (void)updateWithRSS:(RSParsedFeed*)obj {
+- (void)updateWithRSS:(RSParsedFeed*)obj postUnreadCountChange:(BOOL)flag {
 	if (![self.title isEqualToString:obj.title])       self.title = obj.title;
 	if (![self.subtitle isEqualToString:obj.subtitle]) self.subtitle = obj.subtitle;
 	if (![self.link isEqualToString:obj.link])         self.link = obj.link;
 	
-	NSMutableSet<NSString*> *urls = [[self.items valueForKeyPath:@"link"] mutableCopy];
+	int32_t unreadBefore = self.unreadCount;
-	if ([self addMissingArticles:obj updateLinks:urls]) // will remove links in 'urls' that should be kept
+	NSMutableSet<NSString*> *urls = [[self.articles valueForKeyPath:@"link"] mutableCopy];
+	[self addMissingArticles:obj updateLinks:urls]; // will remove links in 'urls' that should be kept
+	if (urls.count > 0)
 		[self deleteArticlesWithLink:urls]; // remove old, outdated articles
+	if (flag) {
+		NSNumber *cDiff = [NSNumber numberWithInteger:self.unreadCount - unreadBefore];
+		[[NSNotificationCenter defaultCenter] postNotificationName:kNotificationTotalUnreadCountChanged object:cDiff];
+	}
 }
 
 /**
@@ -47,7 +72,7 @@
  @return @c YES if new items were added, @c NO otherwise.
  */
 - (BOOL)addMissingArticles:(RSParsedFeed*)obj updateLinks:(NSMutableSet<NSString*>*)urls {
-	int latestID = [[self.items valueForKeyPath:@"@max.sortIndex"] intValue];
+	int latestID = [[self.articles valueForKeyPath:@"@max.sortIndex"] intValue];
 	__block int newOnes = 0;
 	[obj.articles enumerateObjectsWithOptions:NSEnumerationReverse usingBlock:^(RSParsedArticle * _Nonnull article, BOOL * _Nonnull stop) {
 		// reverse enumeration ensures correct article order
@@ -68,17 +93,17 @@
  Create article based on input and insert into core data storage.
  */
 - (void)insertArticle:(RSParsedArticle*)entry atIndex:(int)idx {
-	FeedItem *b = [[FeedItem alloc] initWithEntity:FeedItem.entity insertIntoManagedObjectContext:self.managedObjectContext];
+	FeedArticle *fa = [[FeedArticle alloc] initWithEntity:FeedArticle.entity insertIntoManagedObjectContext:self.managedObjectContext];
-	b.sortIndex = (int32_t)idx;
+	fa.sortIndex = (int32_t)idx;
-	b.unread = YES;
+	fa.unread = YES;
-	b.guid = entry.guid;
+	fa.guid = entry.guid;
-	b.title = entry.title;
+	fa.title = entry.title;
-	b.abstract = entry.abstract;
+	fa.abstract = entry.abstract;
-	b.body = entry.body;
+	fa.body = entry.body;
-	b.author = entry.author;
+	fa.author = entry.author;
-	b.link = entry.link;
+	fa.link = entry.link;
-	b.published = entry.datePublished;
+	fa.published = entry.datePublished;
-	[self addItemsObject:b];
+	[self addArticlesObject:fa];
 }
 
 /**
@@ -87,28 +112,29 @@
 - (void)deleteArticlesWithLink:(NSMutableSet<NSString*>*)urls {
 	if (!urls || urls.count == 0)
 		return;
-	
 	self.articleCount -= (int32_t)urls.count;
-	for (FeedItem *item in self.items) {
+	for (FeedArticle *fa in self.articles) {
-		if ([urls containsObject:item.link]) {
+		if ([urls containsObject:fa.link]) {
-			[urls removeObject:item.link];
+			[urls removeObject:fa.link];
-			if (item.unread)
+			if (fa.unread)
 				self.unreadCount -= 1;
 			// TODO: keep unread articles?
-			[item.managedObjectContext deleteObject:item];
+			[fa.managedObjectContext deleteObject:fa];
 			if (urls.count == 0)
 				break;
 		}
 	}
 }
 
+#pragma mark - Article Properties -
+
 /**
  @return Articles sorted by attribute @c sortIndex with descending order (newest items first).
  */
-- (NSArray<FeedItem*>*)sortedArticles {
+- (NSArray<FeedArticle*>*)sortedArticles {
-	if (self.items.count == 0)
+	if (self.articles.count == 0)
 		return nil;
-	return [self.items sortedArrayUsingDescriptors:@[[NSSortDescriptor sortDescriptorWithKey:@"sortIndex" ascending:NO]]];
+	return [self.articles sortedArrayUsingDescriptors:@[[NSSortDescriptor sortDescriptorWithKey:@"sortIndex" ascending:NO]]];
 }
 
 /**
@@ -135,9 +161,9 @@
  @param readFlag @c YES: mark items read; @c NO: mark items unread
  */
 - (int)markAllArticlesRead:(BOOL)readFlag {
-	for (FeedItem *i in self.items) {
+	for (FeedArticle *fa in self.articles) {
-		if (i.unread == readFlag)
+		if (fa.unread == readFlag)
-			i.unread = !readFlag;
+			fa.unread = !readFlag;
 	}
 	int32_t oldCount = self.unreadCount;
 	int32_t newCount = (readFlag ? 0 : self.articleCount);

baRSS/Categories/FeedGroup+Ext.h

@@ -20,28 +20,25 @@
 //  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 //  SOFTWARE.
 
-#import "FeedConfig+CoreDataClass.h"
+#import "FeedGroup+CoreDataClass.h"
 
-@class FeedItem, RSParsedFeed;
+@interface FeedGroup (Ext)
-
+/// Enum type to distinguish different @c FeedGroup types: @c GROUP, @c FEED, @c SEPARATOR
-@interface FeedConfig (Ext)
-/// Enum type to distinguish different @c FeedConfig types
 typedef enum int16_t {
+	/// Other types: @c GROUP, @c FEED, @c SEPARATOR
 	GROUP = 0,
 	FEED = 1,
 	SEPARATOR = 2
-} FeedConfigType;
+} FeedGroupType;
 
-@property (getter=typ, setter=setTyp:) FeedConfigType typ;
+@property (readonly) FeedGroupType typ;
+
++ (instancetype)newGroup:(FeedGroupType)type inContext:(NSManagedObjectContext*)context;
+- (void)setName:(NSString*)name andRefreshString:(NSString*)refreshStr;
 // Handle children and parents
 - (NSString*)indexPathString;
-- (NSMutableArray<FeedConfig*>*)allParents;
+- (NSMutableArray<FeedGroup*>*)allParents;
 - (BOOL)iterateSorted:(BOOL)ordered overDescendantFeeds:(void(^)(Feed *feed, BOOL* cancel))block;
-// Update feed and meta
-- (void)updateRSSFeed:(RSParsedFeed*)obj;
-- (void)setEtag:(NSString*)etag modified:(NSString*)modified;
-- (void)calculateAndSetScheduled;
 // Printing
-- (NSString*)readableRefreshString;
 - (NSString*)readableDescription;
 @end

baRSS/Categories/FeedGroup+Ext.m

@@ -20,16 +20,31 @@
 //  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 //  SOFTWARE.
 
-#import "FeedConfig+Ext.h"
+#import "FeedGroup+Ext.h"
+#import "FeedMeta+Ext.h"
 #import "Feed+Ext.h"
-#import "FeedMeta+CoreDataClass.h"
-#import "Constants.h"
 
-@implementation FeedConfig (Ext)
+@implementation FeedGroup (Ext)
-/// Enum tpye getter see @c FeedConfigType
+/// Enum tpye getter see @c FeedGroupType
-- (FeedConfigType)typ { return (FeedConfigType)self.type; }
+- (FeedGroupType)typ { return (FeedGroupType)self.type; }
-/// Enum type setter see @c FeedConfigType
+/// Enum type setter see @c FeedGroupType
-- (void)setTyp:(FeedConfigType)typ { self.type = typ; }
+- (void)setTyp:(FeedGroupType)typ { self.type = typ; }
+
+
+/// Create new instance and set @c Feed and @c FeedMeta if group type is @c FEED
++ (instancetype)newGroup:(FeedGroupType)type inContext:(NSManagedObjectContext*)moc {
+	FeedGroup *fg = [[FeedGroup alloc] initWithEntity: FeedGroup.entity insertIntoManagedObjectContext:moc];
+	fg.typ = type;
+	if (type == FEED)
+		fg.feed = [Feed newFeedAndMetaInContext:moc];
+	return fg;
+}
+
+/// Set name and refreshStr attributes. @note Only values that differ will be updated.
+- (void)setName:(NSString*)name andRefreshString:(NSString*)refreshStr {
+	if (![self.name isEqualToString: name])            self.name = name;
+	if (![self.refreshStr isEqualToString:refreshStr]) self.refreshStr = refreshStr;
+}
 
 
 #pragma mark - Handle Children And Parents -
@@ -43,14 +58,14 @@
 }
 
 /// @return Children sorted by attribute @c sortIndex (same order as in preferences).
-- (NSArray<FeedConfig*>*)sortedChildren {
+- (NSArray<FeedGroup*>*)sortedChildren {
 	if (self.children.count == 0)
 		return nil;
 	return [self.children sortedArrayUsingDescriptors:@[[NSSortDescriptor sortDescriptorWithKey:@"sortIndex" ascending:YES]]];
 }
 
-/// @return @c NSArray of all ancestors: First object is root. Last object is the @c FeedConfig that executed the command.
+/// @return @c NSArray of all ancestors: First object is root. Last object is the @c FeedGroup that executed the command.
-- (NSMutableArray<FeedConfig*>*)allParents {
+- (NSMutableArray<FeedGroup*>*)allParents {
 	if (self.parent == nil)
 		return [NSMutableArray arrayWithObject:self];
 	NSMutableArray *arr = [self.parent allParents];
@@ -71,8 +86,8 @@
 		block(self.feed, &stopEarly);
 		if (stopEarly) return NO;
 	} else {
-		for (FeedConfig *fc in (ordered ? [self sortedChildren] : self.children)) {
+		for (FeedGroup *fg in (ordered ? [self sortedChildren] : self.children)) {
-			if (![fc iterateSorted:ordered overDescendantFeeds:block])
+			if (![fg iterateSorted:ordered overDescendantFeeds:block])
 				return NO;
 		}
 	}
@@ -80,57 +95,16 @@
 }
 
 
-#pragma mark - Update Feed And Meta -
-
-
-/// Delete any existing feed object and parse new one. Read state will be copied.
-- (void)updateRSSFeed:(RSParsedFeed*)obj {
-	if (!self.feed) {
-		self.feed = [[Feed alloc] initWithEntity:Feed.entity insertIntoManagedObjectContext:self.managedObjectContext];
-		self.feed.indexPath = [self indexPathString];
-	}
-	int32_t unreadBefore = self.feed.unreadCount;
-	[self.feed updateWithRSS:obj];
-	NSNumber *cDiff = [NSNumber numberWithInteger:self.feed.unreadCount - unreadBefore];
-	[[NSNotificationCenter defaultCenter] postNotificationName:kNotificationTotalUnreadCountChanged object:cDiff];
-}
-
-/// Update FeedMeta or create new one if needed.
-- (void)setEtag:(NSString*)etag modified:(NSString*)modified {
-	if (!self.meta) {
-		self.meta = [[FeedMeta alloc] initWithEntity:FeedMeta.entity insertIntoManagedObjectContext:self.managedObjectContext];
-	}
-	if (![self.meta.httpEtag isEqualToString:etag])         self.meta.httpEtag = etag;
-	if (![self.meta.httpModified isEqualToString:modified]) self.meta.httpModified = modified;
-}
-
-/// Calculate date from @c refreshNum and @c refreshUnit and set as next scheduled feed update.
-- (void)calculateAndSetScheduled {
-	self.scheduled = [[NSDate date] dateByAddingTimeInterval:[self timeInterval]];
-}
-
-/// @return Time interval respecting the selected unit. E.g., returns @c 180 for @c '3m'
-- (NSTimeInterval)timeInterval {
-	static const int unit[] = {1, 60, 3600, 86400, 604800}; // smhdw
-	return self.refreshNum * unit[self.refreshUnit % 5];
-}
-
-
 #pragma mark - Printing -
 
 
-/// @return Formatted string for update interval ( e.g., @c 30m or @c 12h )
-- (NSString*)readableRefreshString {
-	return [NSString stringWithFormat:@"%d%c", self.refreshNum, [@"smhdw" characterAtIndex:self.refreshUnit % 5]];
-}
-
 /// @return Simplified description of the feed object.
 - (NSString*)readableDescription {
 	switch (self.typ) {
 		case SEPARATOR: return @"-------------";
 		case GROUP: return [NSString stringWithFormat:@"%@", self.name];
 		case FEED:
-			return [NSString stringWithFormat:@"%@ (%@) - %@", self.name, self.url, [self readableRefreshString]];
+			return [NSString stringWithFormat:@"%@ (%@) - %@", self.name, self.feed.meta.url, self.refreshStr];
 	}
 }
 

baRSS/Categories/FeedMeta+Ext.h

@@ -0,0 +1,33 @@
+//
+//  The MIT License (MIT)
+//  Copyright (c) 2018 Oleg Geier
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy of
+//  this software and associated documentation files (the "Software"), to deal in
+//  the Software without restriction, including without limitation the rights to
+//  use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+//  of the Software, and to permit persons to whom the Software is furnished to do
+//  so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+
+#import "FeedMeta+CoreDataClass.h"
+
+@interface FeedMeta (Ext)
+- (void)setErrorAndPostponeSchedule;
+- (void)calculateAndSetScheduled;
+
+- (void)setEtag:(NSString*)etag modified:(NSString*)modified;
+- (BOOL)setURL:(NSString*)url refresh:(int32_t)refresh unit:(int16_t)unit;
+
+- (NSString*)readableRefreshString;
+@end

baRSS/Categories/FeedMeta+Ext.m

@@ -0,0 +1,71 @@
+//
+//  The MIT License (MIT)
+//  Copyright (c) 2018 Oleg Geier
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy of
+//  this software and associated documentation files (the "Software"), to deal in
+//  the Software without restriction, including without limitation the rights to
+//  use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+//  of the Software, and to permit persons to whom the Software is furnished to do
+//  so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+
+#import "FeedMeta+Ext.h"
+
+@implementation FeedMeta (Ext)
+
+/// Increment @c errorCount (max. 19) and set new @c scheduled (2^N seconds, max. 6 days).
+- (void)setErrorAndPostponeSchedule {
+	int16_t n = self.errorCount + 1;
+	self.errorCount = (n < 1 ? 1 : (n > 19 ? 19 : n)); // between: 2 sec and 6 days
+	NSTimeInterval retryWaitTime = pow(2, self.errorCount); // 2^n seconds
+	self.scheduled = [NSDate dateWithTimeIntervalSinceNow:retryWaitTime];
+}
+
+/// Calculate date from @c refreshNum and @c refreshUnit and set as next scheduled feed update.
+- (void)calculateAndSetScheduled {
+	NSTimeInterval interval = [self timeInterval]; // 0 if refresh = 0 (update deactivated)
+	self.scheduled = (interval <= 0 ? nil : [[NSDate date] dateByAddingTimeInterval:interval]);
+}
+
+/// Set etag and modified attributes. @note Only values that differ will be updated.
+- (void)setEtag:(NSString*)etag modified:(NSString*)modified {
+	if (![self.etag isEqualToString:etag])         self.etag = etag;
+	if (![self.modified isEqualToString:modified]) self.modified = modified;
+}
+
+/**
+ Set download url and refresh interval (popup button selection). @note Only values that differ will be updated.
+
+ @return @c YES if refresh interval has changed
+ */
+- (BOOL)setURL:(NSString*)url refresh:(int32_t)refresh unit:(int16_t)unit {
+	BOOL intervalChanged = (self.refreshNum != refresh || self.refreshUnit != unit);
+	if (![self.url isEqualToString:url]) self.url = url;
+	if (self.refreshNum != refresh)      self.refreshNum = refresh;
+	if (self.refreshUnit != unit)        self.refreshUnit = unit;
+	return intervalChanged;
+}
+
+/// @return Time interval respecting the selected unit. E.g., returns @c 180 for @c '3m'
+- (NSTimeInterval)timeInterval {
+	static const int unit[] = {1, 60, 3600, 86400, 604800}; // smhdw
+	return self.refreshNum * unit[self.refreshUnit % 5];
+}
+
+/// @return Formatted string for update interval ( e.g., @c 30m or @c 12h )
+- (NSString*)readableRefreshString {
+	return [NSString stringWithFormat:@"%d%c", self.refreshNum, [@"smhdw" characterAtIndex:self.refreshUnit % 5]];
+}
+
+@end

baRSS/DBv1.xcdatamodeld/DBv1.xcdatamodel/contents

@@ -7,24 +7,12 @@
         <attribute name="subtitle" optional="YES" attributeType="String" syncable="YES"/>
         <attribute name="title" optional="YES" attributeType="String" syncable="YES"/>
         <attribute name="unreadCount" optional="YES" attributeType="Integer 32" defaultValueString="0" usesScalarValueType="YES" syncable="YES"/>
-        <relationship name="config" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="FeedConfig" inverseName="feed" inverseEntity="FeedConfig" syncable="YES"/>
+        <relationship name="articles" optional="YES" toMany="YES" deletionRule="Cascade" destinationEntity="FeedArticle" inverseName="feed" inverseEntity="FeedArticle" syncable="YES"/>
-        <relationship name="items" optional="YES" toMany="YES" deletionRule="Cascade" destinationEntity="FeedItem" inverseName="feed" inverseEntity="FeedItem" syncable="YES"/>
+        <relationship name="group" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="FeedGroup" inverseName="feed" inverseEntity="FeedGroup" syncable="YES"/>
+        <relationship name="icon" optional="YES" maxCount="1" deletionRule="Cascade" destinationEntity="FeedIcon" inverseName="feed" inverseEntity="FeedIcon" syncable="YES"/>
+        <relationship name="meta" optional="YES" maxCount="1" deletionRule="Cascade" destinationEntity="FeedMeta" inverseName="feed" inverseEntity="FeedMeta" syncable="YES"/>
     </entity>
-    <entity name="FeedConfig" representedClassName="FeedConfig" syncable="YES" codeGenerationType="class">
+    <entity name="FeedArticle" representedClassName="FeedArticle" syncable="YES" codeGenerationType="class">
-        <attribute name="errorCount" optional="YES" attributeType="Integer 16" defaultValueString="0" usesScalarValueType="YES" syncable="YES"/>
-        <attribute name="name" optional="YES" attributeType="String" syncable="YES"/>
-        <attribute name="refreshNum" optional="YES" attributeType="Integer 32" defaultValueString="-1" usesScalarValueType="YES" syncable="YES"/>
-        <attribute name="refreshUnit" optional="YES" attributeType="Integer 16" defaultValueString="-1" usesScalarValueType="YES" customClassName="NSUInteger" syncable="YES"/>
-        <attribute name="scheduled" optional="YES" attributeType="Date" usesScalarValueType="NO" syncable="YES"/>
-        <attribute name="sortIndex" optional="YES" attributeType="Integer 32" defaultValueString="0" usesScalarValueType="YES" syncable="YES"/>
-        <attribute name="type" optional="YES" attributeType="Integer 16" defaultValueString="-1" usesScalarValueType="YES" syncable="YES"/>
-        <attribute name="url" optional="YES" attributeType="String" syncable="YES"/>
-        <relationship name="children" optional="YES" toMany="YES" deletionRule="Cascade" destinationEntity="FeedConfig" inverseName="parent" inverseEntity="FeedConfig" syncable="YES"/>
-        <relationship name="feed" optional="YES" maxCount="1" deletionRule="Cascade" destinationEntity="Feed" inverseName="config" inverseEntity="Feed" syncable="YES"/>
-        <relationship name="meta" optional="YES" maxCount="1" deletionRule="Cascade" destinationEntity="FeedMeta" inverseName="config" inverseEntity="FeedMeta" syncable="YES"/>
-        <relationship name="parent" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="FeedConfig" inverseName="children" inverseEntity="FeedConfig" syncable="YES"/>
-    </entity>
-    <entity name="FeedItem" representedClassName="FeedItem" syncable="YES" codeGenerationType="class">
         <attribute name="abstract" optional="YES" attributeType="String" syncable="YES"/>
         <attribute name="author" optional="YES" attributeType="String" syncable="YES"/>
         <attribute name="body" optional="YES" attributeType="String" syncable="YES"/>
@@ -34,18 +22,36 @@
         <attribute name="sortIndex" optional="YES" attributeType="Integer 32" defaultValueString="0" usesScalarValueType="YES" syncable="YES"/>
         <attribute name="title" optional="YES" attributeType="String" syncable="YES"/>
         <attribute name="unread" optional="YES" attributeType="Boolean" defaultValueString="YES" usesScalarValueType="YES" syncable="YES"/>
-        <relationship name="feed" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="Feed" inverseName="items" inverseEntity="Feed" syncable="YES"/>
+        <relationship name="feed" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="Feed" inverseName="articles" inverseEntity="Feed" syncable="YES"/>
+    </entity>
+    <entity name="FeedGroup" representedClassName="FeedGroup" syncable="YES" codeGenerationType="class">
+        <attribute name="name" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="refreshStr" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="sortIndex" optional="YES" attributeType="Integer 32" defaultValueString="0" usesScalarValueType="YES" syncable="YES"/>
+        <attribute name="type" optional="YES" attributeType="Integer 16" defaultValueString="-1" usesScalarValueType="YES" syncable="YES"/>
+        <relationship name="children" optional="YES" toMany="YES" deletionRule="Cascade" destinationEntity="FeedGroup" inverseName="parent" inverseEntity="FeedGroup" syncable="YES"/>
+        <relationship name="feed" optional="YES" maxCount="1" deletionRule="Cascade" destinationEntity="Feed" inverseName="group" inverseEntity="Feed" syncable="YES"/>
+        <relationship name="parent" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="FeedGroup" inverseName="children" inverseEntity="FeedGroup" syncable="YES"/>
+    </entity>
+    <entity name="FeedIcon" representedClassName="FeedIcon" syncable="YES" codeGenerationType="class">
+        <attribute name="icon" optional="YES" attributeType="Binary" customClassName="NSImage" syncable="YES"/>
+        <relationship name="feed" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="Feed" inverseName="icon" inverseEntity="Feed" syncable="YES"/>
     </entity>
     <entity name="FeedMeta" representedClassName="FeedMeta" syncable="YES" codeGenerationType="class">
-        <attribute name="httpEtag" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="errorCount" optional="YES" attributeType="Integer 16" defaultValueString="0" usesScalarValueType="YES" syncable="YES"/>
-        <attribute name="httpModified" optional="YES" attributeType="String" syncable="YES"/>
+        <attribute name="etag" optional="YES" attributeType="String" syncable="YES"/>
-        <attribute name="icon" optional="YES" attributeType="Binary" customClassName="NSImage" syncable="YES"/>
+        <attribute name="modified" optional="YES" attributeType="String" syncable="YES"/>
-        <relationship name="config" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="FeedConfig" inverseName="meta" inverseEntity="FeedConfig" syncable="YES"/>
+        <attribute name="refreshNum" optional="YES" attributeType="Integer 32" defaultValueString="-1" usesScalarValueType="YES" syncable="YES"/>
+        <attribute name="refreshUnit" optional="YES" attributeType="Integer 16" defaultValueString="-1" usesScalarValueType="YES" customClassName="NSUInteger" syncable="YES"/>
+        <attribute name="scheduled" optional="YES" attributeType="Date" usesScalarValueType="NO" syncable="YES"/>
+        <attribute name="url" optional="YES" attributeType="String" syncable="YES"/>
+        <relationship name="feed" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="Feed" inverseName="meta" inverseEntity="Feed" syncable="YES"/>
     </entity>
     <elements>
-        <element name="Feed" positionX="-229.09375" positionY="-2.30859375" width="128" height="165"/>
+        <element name="Feed" positionX="-278.84765625" positionY="-112.953125" width="128" height="195"/>
-        <element name="FeedConfig" positionX="-441.87109375" positionY="-47.390625" width="128" height="225"/>
+        <element name="FeedGroup" positionX="-460.37890625" positionY="-111.62890625" width="130.52734375" height="150"/>
-        <element name="FeedItem" positionX="-28.140625" positionY="-17.359375" width="128" height="195"/>
+        <element name="FeedArticle" positionX="-96.77734375" positionY="-113.83984375" width="128" height="195"/>
-        <element name="FeedMeta" positionX="-234" positionY="72" width="128" height="105"/>
+        <element name="FeedIcon" positionX="-202.79296875" positionY="137.71875" width="128" height="75"/>
+        <element name="FeedMeta" positionX="-348.02734375" positionY="136.89453125" width="128" height="165"/>
     </elements>
 </model>

baRSS/FeedDownload.h

@@ -28,5 +28,5 @@
 + (void)registerNetworkChangeNotification;
 + (void)unregisterNetworkChangeNotification;
 + (BOOL)isNetworkReachable;
-+ (void)scheduleNextUpdate:(BOOL)forceUpdate;
++ (void)scheduleNextUpdateForced:(BOOL)flag;
 @end

baRSS/FeedDownload.m

@@ -23,6 +23,9 @@
 #import "FeedDownload.h"
 #import "Constants.h"
 #import "StoreCoordinator.h"
+#import "Feed+Ext.h"
+#import "FeedMeta+Ext.h"
+
 #import <SystemConfiguration/SystemConfiguration.h>
 
 static SCNetworkReachabilityRef _reachability = NULL;
@@ -31,6 +34,7 @@ static BOOL _isReachable = NO;
 
 @implementation FeedDownload
 
+/// @return New request with no caching policy and timeout interval of 30 seconds.
 + (NSMutableURLRequest*)newRequestURL:(NSString*)url {
 	NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:url]];
 	req.timeoutInterval = 30;
@@ -40,16 +44,20 @@ static BOOL _isReachable = NO;
 	return req;
 }
 
-+ (NSURLRequest*)newRequest:(FeedConfig*)config {
+/// @return New request with etag and modified headers set.
-	NSMutableURLRequest *req = [self newRequestURL:config.url];
++ (NSURLRequest*)newRequest:(FeedMeta*)meta {
-	NSString* etag = [config.meta.httpEtag stringByReplacingOccurrencesOfString:@"-gzip" withString:@""];
+	NSMutableURLRequest *req = [self newRequestURL:meta.url];
-	if (config.meta.httpModified.length > 0)
+	NSString* etag = [meta.etag stringByReplacingOccurrencesOfString:@"-gzip" withString:@""];
-		[req setValue:config.meta.httpModified forHTTPHeaderField:@"If-Modified-Since"];
+	if (meta.modified.length > 0)
+		[req setValue:meta.modified forHTTPHeaderField:@"If-Modified-Since"];
 	if (etag.length > 0)
 		[req setValue:etag forHTTPHeaderField:@"If-None-Match"]; // ETag
 	return req;
 }
 
+/**
+ Perform feed download request from URL alone. Not updating any @c Feed item.
+ */
 + (void)newFeed:(NSString *)url block:(void(^)(RSParsedFeed *feed, NSError* error, NSHTTPURLResponse* response))block {
 	[[[NSURLSession sharedSession] dataTaskWithRequest:[self newRequestURL:url] completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
 		NSHTTPURLResponse* httpResponse = (NSHTTPURLResponse*)response;
@@ -59,6 +67,10 @@ static BOOL _isReachable = NO;
 		}
 		RSXMLData *xml = [[RSXMLData alloc] initWithData:data urlString:url];
 		RSParseFeed(xml, ^(RSParsedFeed * _Nullable parsedFeed, NSError * _Nullable err) {
+			if (!err && (!parsedFeed || parsedFeed.articles.count == 0)) { // TODO: this should be fixed in RSXMLParser
+				NSString *errDesc = NSLocalizedString(@"URL does not contain a RSS feed. Can't parse feed items.", nil);
+				err = [NSError errorWithDomain:NSURLErrorDomain code:NSURLErrorUnsupportedURL userInfo:@{NSLocalizedDescriptionKey: errDesc}];
+			}
 			block(parsedFeed, err, httpResponse);
 		});
 	}] resume];
@@ -68,7 +80,12 @@ static BOOL _isReachable = NO;
 #pragma mark - Update existing feeds -
 
 
-+ (void)scheduleNextUpdate:(BOOL)forceUpdate {
+/**
+ Get date of next update schedule and start @c updateTimer.
+
+ @param forceUpdate If @c YES all feeds will be downloaded regardless of scheduled date.
+ */
++ (void)scheduleNextUpdateForced:(BOOL)forceUpdate {
 	static NSTimer *_updateTimer;
 	@synchronized (_updateTimer) { // TODO: dig into analyzer warning
 		if (_updateTimer) {
@@ -80,7 +97,8 @@ static BOOL _isReachable = NO;
 	NSDate *nextTime = [NSDate dateWithTimeIntervalSinceNow:0.2];
 	if (!forceUpdate) {
 		nextTime = [StoreCoordinator nextScheduledUpdate];
-		if (!nextTime || [nextTime timeIntervalSinceNow] < 0) { // mostly, if app was closed for a long time
+		if (!nextTime) return; // no timer means no feeds to update
+		if ([nextTime timeIntervalSinceNow] < 0) { // mostly, if app was closed for a long time
 			nextTime = [NSDate dateWithTimeIntervalSinceNow:2]; // TODO: retry in 2 sec?
 		}
 	}
@@ -91,82 +109,97 @@ static BOOL _isReachable = NO;
 	[[NSRunLoop mainRunLoop] addTimer:_updateTimer forMode:NSRunLoopCommonModes];
 }
 
+/**
+ Called when schedule timer has run out (earliest scheduled date). Or if forced by user request.
+
+ @param timer @c NSTimer @c .userInfo should contain a @c BOOL value whether to force an update of all feeds @c (YES).
+ */
 + (void)scheduledUpdateTimer:(NSTimer*)timer {
 	NSLog(@"fired");
 	BOOL forceAll = [timer.userInfo boolValue];
 	// TODO: check internet connection
 	// TODO: disable menu item 'update all' during update
 	__block NSManagedObjectContext *childContext = [StoreCoordinator createChildContext];
-	NSArray<FeedConfig*> *list = [StoreCoordinator getListOfFeedsThatNeedUpdate:forceAll inContext:childContext];
+	NSArray<Feed*> *list = [StoreCoordinator getListOfFeedsThatNeedUpdate:forceAll inContext:childContext];
 	if (list.count == 0) {
 		NSLog(@"ERROR: Something went wrong, timer fired too early.");
 		[childContext reset];
 		childContext = nil;
 		// thechnically should never happen, anyway we need to reset the timer
-		[self scheduleNextUpdate:NO]; // NO, since forceAll will get ALL items and shouldn't be 0
+		[self scheduleNextUpdateForced:NO]; // NO, since forceAll will get ALL items and shouldn't be 0
 		return; // nothing to do here
 	}
 	dispatch_group_t group = dispatch_group_create();
-	for (FeedConfig *c in list) {
+	for (Feed *feed in list) {
-		[self downloadFeedForConfig:c group:group];
+		[self downloadFeed:feed group:group];
 	}
 	dispatch_group_notify(group, dispatch_get_main_queue(), ^{
 		[StoreCoordinator saveContext:childContext andParent:YES];
 		[[NSNotificationCenter defaultCenter] postNotificationName:kNotificationFeedUpdated object:[list valueForKeyPath:@"objectID"]];
 		[childContext reset];
 		childContext = nil;
-		[self scheduleNextUpdate:NO]; // after forced update, continue regular cycle
+		[self scheduleNextUpdateForced:NO]; // after forced update, continue regular cycle
 	});
 }
 
-+ (void)downloadFeedForConfig:(FeedConfig*)config group:(dispatch_group_t)group {
+/**
+ Start download request with existing @c Feed object. Reuses etag and modified headers.
+
+ @param feed @c Feed on which the update is executed.
+ @param group Mutex to count completion of all downloads.
+ */
++ (void)downloadFeed:(Feed*)feed group:(dispatch_group_t)group {
 	if (!_isReachable) return;
 	dispatch_group_enter(group);
-	[[[NSURLSession sharedSession] dataTaskWithRequest:[self newRequest:config] completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
+	[[[NSURLSession sharedSession] dataTaskWithRequest:[self newRequest:feed.meta] completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
-		[config.managedObjectContext performBlock:^{
+		[feed.managedObjectContext performBlock:^{
-			// core data block inside of url session block; otherwise config access will EXC_BAD_INSTRUCTION
+			// core data block inside of url session block; otherwise access will EXC_BAD_INSTRUCTION
 			if (error) {
-				int16_t n = config.errorCount + 1;
+				[feed.meta setErrorAndPostponeSchedule];
-				config.errorCount = (n < 1 ? 1 : (n > 19 ? 19 : n)); // between: 2 sec and 6 days
-				NSTimeInterval retryWaitTime = pow(2, config.errorCount); // 2^n seconds
-				config.scheduled = [NSDate dateWithTimeIntervalSinceNow:retryWaitTime];
 				// TODO: remove logging
-				NSLog(@"Error loading: %@ (%d)", response.URL, config.errorCount);
+				NSLog(@"Error loading: %@ (%d)", response.URL, feed.meta.errorCount);
 			} else {
-				config.errorCount = 0; // reset counter
+				feed.meta.errorCount = 0; // reset counter
-				[self downloadSuccessful:data forFeed:config response:(NSHTTPURLResponse*)response];
+				[self downloadSuccessful:data forFeed:feed response:(NSHTTPURLResponse*)response];
 			}
 			dispatch_group_leave(group);
 		}];
 	}] resume];
 }
 
-+ (void)downloadSuccessful:(NSData*)data forFeed:(FeedConfig*)config response:(NSHTTPURLResponse*)http {
+/**
+ Parse RSS feed data and save to persistent store. If HTTP 304 (not modified) skip feed evaluation.
+
+ @param data Raw data from request.
+ @param feed @c Feed on which the update is executed.
+ @param http Download response containing the statusCode and etag / modified headers.
+ */
++ (void)downloadSuccessful:(NSData*)data forFeed:(Feed*)feed response:(NSHTTPURLResponse*)http {
 	if ([http statusCode] != 304) {
 		// should be fine to call synchronous since dataTask is already in the background (always? proof?)
-		RSXMLData *xml = [[RSXMLData alloc] initWithData:data urlString:config.url];
+		RSXMLData *xml = [[RSXMLData alloc] initWithData:data urlString:feed.meta.url];
 		RSParsedFeed *parsed = RSParseFeedSync(xml, NULL);
 		if (parsed) {
 			// TODO: add support for media player?
 			// <enclosure url="https://url.mp3" length="63274022" type="audio/mpeg" />
-			[config updateRSSFeed:parsed];
+			[feed updateWithRSS:parsed postUnreadCountChange:YES];
 		}
 	}
-	[config setEtag:[http allHeaderFields][@"Etag"] modified:[http allHeaderFields][@"Date"]]; // @"Expires", @"Last-Modified"
+	[feed.meta setEtag:[http allHeaderFields][@"Etag"] modified:[http allHeaderFields][@"Date"]]; // @"Expires", @"Last-Modified"
 	// Don't update redirected url since it happened in the background; User may not recognize url
-	[config calculateAndSetScheduled];
+	[feed.meta calculateAndSetScheduled];
-//	[config mergeChangesAndSave];
+	// TODO: save changes for this feed only?
-//	[config.managedObjectContext performBlock:^{
+//	[[NSNotificationCenter defaultCenter] postNotificationName:kNotificationFeedUpdated object:feed.objectID];
-//		[[NSNotificationCenter defaultCenter] postNotificationName:kNotificationFeedUpdated object:config.objectID];
-//	}];
 }
 
 
 #pragma mark - Network Connection -
 
 
+/// External getter to check wheter current network state is reachable.
 + (BOOL)isNetworkReachable { return _isReachable; }
 
+/// Set callback on @c self to listen for network reachability changes.
 + (void)registerNetworkChangeNotification {
 	// https://stackoverflow.com/questions/11240196/notification-when-wifi-connected-os-x
 	if (_reachability != NULL) return;
@@ -184,6 +217,7 @@ static BOOL _isReachable = NO;
 	}
 }
 
+/// Remove @c self callback (network reachability changes).
 + (void)unregisterNetworkChangeNotification {
 	if (_reachability != NULL) {
 		SCNetworkReachabilitySetCallback(_reachability, nil, nil);
@@ -193,6 +227,7 @@ static BOOL _isReachable = NO;
 	}
 }
 
+/// Called when network interface or reachability changes.
 static void networkReachabilityCallback(SCNetworkReachabilityRef target, SCNetworkConnectionFlags flags, void *object) {
 	if (_reachability == NULL)
 		return;
@@ -205,9 +240,10 @@ static void networkReachabilityCallback(SCNetworkReachabilityRef target, SCNetwo
 		NSLog(@"not reachable");
 	}
 	// schedule regardless of state (if not reachable timer will be canceled)
-	[FeedDownload scheduleNextUpdate:NO];
+	[FeedDownload scheduleNextUpdateForced:NO];
 }
 
+/// @return @c YES if network connection established.
 + (BOOL)hasConnectivity:(SCNetworkReachabilityFlags)flags {
 	if ((flags & kSCNetworkReachabilityFlagsReachable) == 0)
 		return NO;

baRSS/Preferences/Feeds Tab/ModalFeedEdit.h

@@ -21,22 +21,20 @@
 //  SOFTWARE.
 
 #import <Cocoa/Cocoa.h>
+#import "ModalSheet.h"
 
-@class FeedConfig;
+@class FeedGroup;
 
-@protocol ModalEditDelegate <NSObject>
+@interface ModalEditDialog : NSViewController
-- (void)modalDidUpdateFeedConfig:(FeedConfig*)config;
++ (instancetype)modalWith:(FeedGroup*)group;
-@end
+- (ModalSheet*)getModalSheet;
-
+- (void)applyChangesToCoreDataObject;
-@protocol ModalFeedConfigEdit <NSObject>
-@property (weak) id<ModalEditDelegate> delegate;
-- (void)updateRepresentedObject; // must call [item.managedObjectContext refreshObject:item mergeChanges:YES];
 @end
 
 
-@interface ModalFeedEdit : NSViewController <ModalFeedConfigEdit, NSTextFieldDelegate>
+@interface ModalFeedEdit : ModalEditDialog <NSTextFieldDelegate>
 @end
 
-@interface ModalGroupEdit : NSViewController <ModalFeedConfigEdit>
+@interface ModalGroupEdit : ModalEditDialog
 @end
 

baRSS/Preferences/Feeds Tab/ModalFeedEdit.m

@@ -23,6 +23,42 @@
 #import "ModalFeedEdit.h"
 #import "FeedDownload.h"
 #import "StoreCoordinator.h"
+#import "Feed+Ext.h"
+#import "FeedMeta+Ext.h"
+#import "FeedGroup+Ext.h"
+
+
+#pragma mark - ModalEditDialog -
+
+
+@interface ModalEditDialog()
+@property (strong) FeedGroup *feedGroup;
+@property (strong) ModalSheet *modalSheet;
+@end
+
+@implementation ModalEditDialog
+/// Dedicated initializer for @c ModalEditDialog subclasses. Ensures @c .feedGroup property is set.
++ (instancetype)modalWith:(FeedGroup*)group {
+	ModalEditDialog *diag = [self new];
+	diag.feedGroup = group;
+	return diag;
+}
+/// @return New @c ModalSheet with its subclass @c .view property as dialog content.
+- (ModalSheet *)getModalSheet {
+	if (!self.modalSheet)
+		self.modalSheet = [ModalSheet modalWithView:self.view];
+	return self.modalSheet;
+}
+/// This method should be overridden by subclasses. Used to save changes to persistent store.
+- (void)applyChangesToCoreDataObject {
+	NSLog(@"[%@] is missing method: -(void)applyChangesToCoreDataObject", [self class]);
+	NSAssert(NO, @"Override required!");
+}
+@end
+
+
+#pragma mark - ModalFeedEdit -
+
 
 @interface ModalFeedEdit()
 @property (weak) IBOutlet NSTextField *url;
@@ -34,143 +70,135 @@
 @property (weak) IBOutlet NSButton *warningIndicator;
 @property (weak) IBOutlet NSPopover *warningPopover;
 
-@property (copy) NSString *previousURL;
+@property (copy) NSString *previousURL; // check if changed and avoid multiple download
 @property (copy) NSString *httpDate;
 @property (copy) NSString *httpEtag;
-@property (strong) NSError *feedError;
+@property (strong) NSError *feedError; // download error or xml parser error
-@property (strong) RSParsedFeed *feedResult;
+@property (strong) RSParsedFeed *feedResult; // parsed result
-
+@property (assign) BOOL didDownloadFeed; // check if feed articles need update
-@property (assign) BOOL shouldSaveObject;
-@property (assign) BOOL shouldDeletePrevArticles;
-@property (assign) BOOL objectNeedsSaving;
-@property (assign) BOOL objectIsModified;
 @end
 
 @implementation ModalFeedEdit
-@synthesize delegate;
 
+/// Init feed edit dialog with default values.
 - (void)viewDidLoad {
 	[super viewDidLoad];
 	self.previousURL = @"";
 	self.refreshNum.intValue = 30;
-	self.shouldSaveObject = NO;
+	[self populateTextFields:self.feedGroup];
-	self.shouldDeletePrevArticles = NO;
+}
-	self.objectNeedsSaving = NO;
-	self.objectIsModified = NO;
-	
-	FeedConfig *fc = [self feedConfigOrNil];
-	if (fc) {
-		self.url.objectValue = fc.url;
-		self.name.objectValue = fc.name;
-		self.refreshNum.intValue = fc.refreshNum;
-		NSInteger unitIndex = fc.refreshUnit;
-		if (unitIndex < 0 || unitIndex > self.refreshUnit.numberOfItems - 1)
-			unitIndex = self.refreshUnit.numberOfItems - 1;
-		[self.refreshUnit selectItemAtIndex:unitIndex];
 
+/**
+ Pre-fill UI control field values with @c FeedGroup properties.
+ */
+- (void)populateTextFields:(FeedGroup*)fg {
+	if (!fg || [fg hasChanges]) return; // hasChanges is true only if newly created
+	self.name.objectValue = fg.name;
+	self.url.objectValue = fg.feed.meta.url;
 	self.previousURL = self.url.stringValue;
+	self.refreshNum.intValue = fg.feed.meta.refreshNum;
+	NSInteger unit = (NSInteger)fg.feed.meta.refreshUnit;
+	if (unit < 0 || unit > self.refreshUnit.numberOfItems - 1)
+		unit = self.refreshUnit.numberOfItems - 1;
+	[self.refreshUnit selectItemAtIndex:unit];
+}
+
+#pragma mark - Edit Feed Data
+
+/**
+ Use UI control field values to update the represented core data object. Also parse new articles if applicable.
+ Set @c scheduled to a new date if refresh interval was changed.
+ */
+- (void)applyChangesToCoreDataObject {
+	FeedMeta *meta = self.feedGroup.feed.meta;
+	BOOL intervalChanged = [meta setURL:self.previousURL refresh:self.refreshNum.intValue unit:(int16_t)self.refreshUnit.indexOfSelectedItem];
+	if (intervalChanged)
+		[meta calculateAndSetScheduled]; // updateTimer will be scheduled once preferences is closed
+	[self.feedGroup setName:self.name.stringValue andRefreshString:[meta readableRefreshString]];
+	if (self.didDownloadFeed) {
+		[meta setEtag:self.httpEtag modified:self.httpDate];
+		[self.feedGroup.feed updateWithRSS:self.feedResult postUnreadCountChange:YES];
 	}
 }
 
-- (void)dealloc {
+/**
-	if (self.shouldSaveObject) {
+ Prepare UI (nullify @c result, @c error and start @c ProgressIndicator) and perform HTTP request.
-		if (self.objectNeedsSaving)
+ Articles will be parsed and stored in class variables.
-			[self updateRepresentedObject];
+ This should avoid unnecessary core data operations if user decides to cancel the edit.
-		FeedConfig *item = [self feedConfigOrNil];
+ The save operation will only be executed if user clicks on the 'OK' button.
-		NSUndoManager *um = item.managedObjectContext.undoManager;
+ */
-		[um endUndoGrouping];
+- (void)downloadRSS {
-		if (!self.objectIsModified) {
+	[self.modalSheet setDoneEnabled:NO];
-			[um disableUndoRegistration];
+	// Assuming the user has not changed title since the last fetch.
-			[um undoNestedGroup];
+	// Reset to "" because after download it will be pre-filled with new feed title
-			[um enableUndoRegistration];
+	if ([self.name.stringValue isEqualToString:self.feedResult.title]) {
-		} else {
+		self.name.stringValue = @"";
-			[self.delegate modalDidUpdateFeedConfig:item];
 	}
-	}
+	self.feedResult = nil;
-}
+	self.feedError = nil;
+	self.httpEtag = nil;
+	self.httpDate = nil;
+	self.didDownloadFeed = NO;
+	[self.spinnerURL startAnimation:nil];
+	[self.spinnerName startAnimation:nil];
 	
-- (void)updateRepresentedObject {
+	[FeedDownload newFeed:self.previousURL block:^(RSParsedFeed *result, NSError *error, NSHTTPURLResponse* response) {
-	FeedConfig *item = [self feedConfigOrNil];
+		dispatch_async(dispatch_get_main_queue(), ^{
-	if (!item)
+			if (self.modalSheet.closeInitiated)
 				return;
-	if (!self.shouldSaveObject) // first call to this method
+			self.didDownloadFeed = YES;
-		[item.managedObjectContext.undoManager beginUndoGrouping];
+			self.feedResult = result;
-	self.shouldSaveObject = YES;
+			self.feedError = error; // MAIN THREAD!: warning indicator .hidden is bound to feedError
-	self.objectNeedsSaving = NO; // after this method it is saved
+			self.httpEtag = [response allHeaderFields][@"Etag"];
-	
+			self.httpDate = [response allHeaderFields][@"Date"]; // @"Expires", @"Last-Modified"
-	// if's to prevent unnecessary undo groups if nothing has changed
+			[self updateTextFieldURL:response.URL.absoluteString andTitle:result.title];
-	if (![item.name isEqualToString: self.name.stringValue])
-		item.name = self.name.stringValue;
-	if (![item.url isEqualToString:self.url.stringValue])
-		item.url = self.url.stringValue;
-	if (item.refreshNum != self.refreshNum.intValue)
-		item.refreshNum = self.refreshNum.intValue;
-	if (item.refreshUnit != self.refreshUnit.indexOfSelectedItem)
-		item.refreshUnit = (int16_t)self.refreshUnit.indexOfSelectedItem;
-	
-	if (self.shouldDeletePrevArticles) {
-		[item updateRSSFeed:self.feedResult];
-		[item setEtag:self.httpEtag modified:self.httpDate];
 			// TODO: add icon download
+			// TODO: play error sound?
+			[self.spinnerURL stopAnimation:nil];
+			[self.spinnerName stopAnimation:nil];
+			[self.modalSheet setDoneEnabled:YES];
+		});
+	}];
+}
+
+/// Set UI TextField values to downloaded values. Title will be updated if TextField is empty. URL on redirect.
+- (void)updateTextFieldURL:(NSString*)responseURL andTitle:(NSString*)feedTitle {
+	// If URL was redirected (e.g., https redirect), replace original text field value with new one
+	if (responseURL.length > 0 && ![responseURL isEqualToString:self.previousURL]) {
+		self.previousURL = responseURL;
+		self.url.stringValue = responseURL;
 	}
-	if ([item.managedObjectContext hasChanges]) {
+	// Copy feed title to text field. (only if user hasn't set anything else yet)
-		self.objectIsModified = YES;
+	if ([self.name.stringValue isEqualToString:@""] && feedTitle.length > 0) {
-		[item calculateAndSetScheduled];
+		self.name.stringValue = feedTitle; // no damage to replace an empty string
-		[item.managedObjectContext refreshObject:item mergeChanges:YES];
 	}
 }
 
-- (FeedConfig*)feedConfigOrNil {
+#pragma mark - NSTextField Delegate
-	if ([self.representedObject isKindOfClass:[FeedConfig class]])
-		return self.representedObject;
-	return nil;
-}
 
+/// Helper method to check whether url was modified since last download.
 - (BOOL)urlHasChanged {
 	return ![self.previousURL isEqualToString:self.url.stringValue];
 }
 
+/// Hide warning button if an error was present but the user changed the url since.
 - (void)controlTextDidChange:(NSNotification *)obj {
 	if (obj.object == self.url) {
 		self.warningIndicator.hidden = (!self.feedError || [self urlHasChanged]);
 	}
 }
 
+/// Whenever the user finished entering the url (return key or focus change) perform a download request.
 - (void)controlTextDidEndEditing:(NSNotification *)obj {
 	if (obj.object == self.url && [self urlHasChanged]) {
-		self.shouldDeletePrevArticles = YES;
+		if (self.modalSheet.closeInitiated)
+			return;
 		self.previousURL = self.url.stringValue;
-		self.feedResult = nil;
+		[self downloadRSS];
-		self.feedError = nil;
-		[self.spinnerURL startAnimation:nil];
-		[self.spinnerName startAnimation:nil];
-		[FeedDownload newFeed:self.previousURL block:^(RSParsedFeed *result, NSError *error, NSHTTPURLResponse* response) {
-			self.feedResult = result;
-			self.httpDate = [response allHeaderFields][@"Date"]; // @"Expires", @"Last-Modified"
-			self.httpEtag = [response allHeaderFields][@"Etag"];
-			dispatch_async(dispatch_get_main_queue(), ^{
-				if (response && ![response.URL.absoluteString isEqualToString:self.url.stringValue]) {
-					// URL was redirected, so replace original text field value with new one
-					self.url.stringValue = response.URL.absoluteString;
-					self.previousURL = self.url.stringValue;
-				}
-				// TODO: play error sound?
-				self.feedError = error; // warning indicator .hidden is bound to feedError
-				self.objectNeedsSaving = YES; // stays YES if this block runs after updateRepresentedObject:
-				[self setTitleFromFeed];
-				[self.spinnerURL stopAnimation:nil];
-				[self.spinnerName stopAnimation:nil];
-			});
-		}];
-	}
-}
-
-- (void)setTitleFromFeed {
-	if ([self.name.stringValue isEqualToString:@""]) {
-		self.name.objectValue = self.feedResult.title;
 	}
 }
 
+/// Warning button next to url text field. Will be visible if an error occurs during download.
 - (IBAction)didClickWarningButton:(NSButton*)sender {
 	if (!self.feedError)
 		return;
@@ -191,51 +219,49 @@
 @end
 
 
-#pragma mark - ModalGroupEdit
+#pragma mark - ModalGroupEdit -
+
 
 @implementation ModalGroupEdit
-@synthesize delegate;
+/// Init view and set group name if edeting an already existing object.
 - (void)viewDidLoad {
 	[super viewDidLoad];
-	if ([self.representedObject isKindOfClass:[FeedConfig class]]) {
+	if (self.feedGroup && ![self.feedGroup hasChanges]) // hasChanges is true only if newly created
-		FeedConfig *fc = self.representedObject;
+		((NSTextField*)self.view).objectValue = self.feedGroup.name;
-		((NSTextField*)self.view).objectValue = fc.name;
-	}
 }
+/// Set one single @c NSTextField as entire view. Populate with default value and placeholder.
 - (void)loadView {
 	NSTextField *tf = [NSTextField textFieldWithString:NSLocalizedString(@"New Group", nil)];
 	tf.placeholderString = NSLocalizedString(@"New Group", nil);
 	tf.autoresizingMask = NSViewWidthSizable | NSViewMinYMargin;
 	self.view = tf;
 }
-- (void)updateRepresentedObject {
+/// Edit of group finished. Save changes to core data object and perform save operation on delegate.
-	if ([self.representedObject isKindOfClass:[FeedConfig class]]) {
+- (void)applyChangesToCoreDataObject {
-		FeedConfig *item = self.representedObject;
 	NSString *name = ((NSTextField*)self.view).stringValue;
-		if (![item.name isEqualToString: name]) {
+	if (![self.feedGroup.name isEqualToString:name])
-			item.name = name;
+		self.feedGroup.name = name;
-			[item.managedObjectContext refreshObject:item mergeChanges:YES];
-			[self.delegate modalDidUpdateFeedConfig:item];
-		}
-	}
 }
 @end
 
 
-#pragma mark - StrictUIntFormatter
+#pragma mark - StrictUIntFormatter -
 
 
 @interface StrictUIntFormatter : NSFormatter
 @end
 
 @implementation StrictUIntFormatter
+/// Display object as integer formatted string.
 - (NSString *)stringForObjectValue:(id)obj {
 	return [NSString stringWithFormat:@"%d", [[NSString stringWithFormat:@"%@", obj] intValue]];
 }
+/// Parse any pasted input as integer.
 - (BOOL)getObjectValue:(out id  _Nullable __autoreleasing *)obj forString:(NSString *)string errorDescription:(out NSString *__autoreleasing  _Nullable *)error {
 	*obj = [[NSNumber numberWithInt:[string intValue]] stringValue];
 	return YES;
 }
+/// Only digits, no other character allowed
 - (BOOL)isPartialStringValid:(NSString *__autoreleasing  _Nonnull *)partialStringPtr proposedSelectedRange:(NSRangePointer)proposedSelRangePtr originalString:(NSString *)origString originalSelectedRange:(NSRange)origSelRange errorDescription:(NSString *__autoreleasing  _Nullable *)error {
 	for (NSUInteger i = 0; i < [*partialStringPtr length]; i++) {
 		unichar c = [*partialStringPtr characterAtIndex:i];

baRSS/Preferences/Feeds Tab/SettingsFeeds.m

@@ -21,18 +21,17 @@
 //  SOFTWARE.
 
 #import "SettingsFeeds.h"
-#import "BarMenu.h"
+#import "Constants.h"
-#import "ModalSheet.h"
-#import "ModalFeedEdit.h"
 #import "DrawImage.h"
 #import "StoreCoordinator.h"
-#import "Constants.h"
+#import "ModalFeedEdit.h"
+#import "Feed+Ext.h"
+#import "FeedGroup+Ext.h"
 
-@interface SettingsFeeds () <ModalEditDelegate>
+@interface SettingsFeeds ()
 @property (weak) IBOutlet NSOutlineView *outlineView;
 @property (weak) IBOutlet NSTreeController *dataStore;
 
-@property (strong) NSViewController<ModalFeedConfigEdit> *modalController;
 @property (strong) NSArray<NSTreeNode*> *currentlyDraggedNodes;
 @property (strong) NSUndoManager *undoManager;
 @end
@@ -60,22 +59,21 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 }
 
 - (IBAction)addFeed:(id)sender {
-	[self showModalForFeedConfig:nil isGroupEdit:NO];
+	[self showModalForFeedGroup:nil isGroupEdit:NO];
 }
 
 - (IBAction)addGroup:(id)sender {
-	[self showModalForFeedConfig:nil isGroupEdit:YES];
+	[self showModalForFeedGroup:nil isGroupEdit:YES];
 }
 
 - (IBAction)addSeparator:(id)sender {
 	[self.undoManager beginUndoGrouping];
-	FeedConfig *sp = [self insertSortedItemAtSelection];
+	[self insertFeedGroupAtSelection:SEPARATOR].name = @"---";
-	sp.name = @"---";
-	sp.typ = SEPARATOR;
 	[self.undoManager endUndoGrouping];
 	[self saveChanges];
 }
 
+/// Remove user selected item from persistent store.
 - (IBAction)remove:(id)sender {
 	[self.undoManager beginUndoGrouping];
 	NSArray<NSTreeNode*> *parentNodes = [self.dataStore.selectedNodes valueForKeyPath:@"parentNode"];
@@ -88,99 +86,104 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 	[[NSNotificationCenter defaultCenter] postNotificationName:kNotificationTotalUnreadCountReset object:nil];
 }
 
+/// Open user selected item for editing.
 - (IBAction)doubleClickOutlineView:(NSOutlineView*)sender {
 	if (sender.clickedRow == -1)
 		return; // ignore clicks on column headers and where no row was selected
-	
+	FeedGroup *fg = [(NSTreeNode*)[sender itemAtRow:sender.clickedRow] representedObject];
-	FeedConfig *fc = [(NSTreeNode*)[sender itemAtRow:sender.clickedRow] representedObject];
+	[self showModalForFeedGroup:fg isGroupEdit:YES]; // yes will be overwritten anyway
-	[self showModalForFeedConfig:fc isGroupEdit:YES]; // yes will be overwritten anyway
 }
 
 
 #pragma mark - Insert & Edit Feed Items
 
 
-- (void)openModalForSelection {
+/**
-	[self showModalForFeedConfig:self.dataStore.selectedObjects.firstObject isGroupEdit:YES]; // yes will be overwritten anyway
+ Open a new modal window to edit the selected @c FeedGroup.
-}
+ @note isGroupEdit @c flag will be overwritten if @c FeedGroup parameter is not @c nil.
  
-- (void)showModalForFeedConfig:(FeedConfig*)obj isGroupEdit:(BOOL)group {
+ @param fg @c FeedGroup to be edited. If @c nil a new object will be created at the current selection.
-	BOOL existingItem = [obj isKindOfClass:[FeedConfig class]];
+ @param flag If @c YES open group edit modal dialog. If @c NO open feed edit modal dialog.
-	if (existingItem) {
+ */
-		if (obj.typ == SEPARATOR) return;
+- (void)showModalForFeedGroup:(FeedGroup*)fg isGroupEdit:(BOOL)flag {
-		group = (obj.typ == GROUP);
+	if (fg.typ == SEPARATOR) return;
-	}
-	self.modalController = (group ? [ModalGroupEdit new] : [ModalFeedEdit new]);
-	self.modalController.representedObject = obj;
-	self.modalController.delegate = self;
-	
-	[self.view.window beginSheet:[ModalSheet modalWithView:self.modalController.view] completionHandler:^(NSModalResponse returnCode) {
-		if (returnCode == NSModalResponseOK) {
-			if (!existingItem) { // create new item
 	[self.undoManager beginUndoGrouping];
-				FeedConfig *item = [self insertSortedItemAtSelection];
+	if (!fg || ![fg isKindOfClass:[FeedGroup class]]) {
-				item.typ = (group ? GROUP : FEED);
+		fg = [self insertFeedGroupAtSelection:(flag ? GROUP : FEED)];
-				self.modalController.representedObject = item;
 	}
-			[self.modalController updateRepresentedObject];
-			if (!existingItem)
-				[self.undoManager endUndoGrouping];
-		}
-		self.modalController = nil;
-	}];
-}
 	
-/// Called after an item was modified. May be called twice if download was still in progress.
+	ModalEditDialog *editDialog = (fg.typ == GROUP ? [ModalGroupEdit modalWith:fg] : [ModalFeedEdit modalWith:fg]);
-- (void)modalDidUpdateFeedConfig:(FeedConfig*)config {
+	
+	[self.view.window beginSheet:[editDialog getModalSheet] completionHandler:^(NSModalResponse returnCode) {
+		if (returnCode == NSModalResponseOK) {
+			[editDialog applyChangesToCoreDataObject];
+			[self.undoManager endUndoGrouping];
+		} else {
+			[self.undoManager endUndoGrouping];
+			[self.dataStore.managedObjectContext rollback];
+		}
+		BOOL hasChanges = [self.dataStore.managedObjectContext hasChanges];
+		if (hasChanges) {
 			[self saveChanges];
-	[[NSNotificationCenter defaultCenter] postNotificationName:kNotificationTotalUnreadCountReset object:nil];
+			[self.dataStore rearrangeObjects];
+		} else {
+			[self.undoManager disableUndoRegistration];
+			[self.undoManager undoNestedGroup];
+			[self.undoManager enableUndoRegistration];
+		}
+	}];
 }
 
 
 #pragma mark - Helper -
 
-/// Insert @c FeedConfig item either after current selection or inside selected folder (if expanded)
+/// Insert @c FeedGroup item either after current selection or inside selected folder (if expanded)
-- (FeedConfig*)insertSortedItemAtSelection {
+- (FeedGroup*)insertFeedGroupAtSelection:(FeedGroupType)type {
-	FeedConfig *newItem = [[FeedConfig alloc] initWithEntity:FeedConfig.entity insertIntoManagedObjectContext:self.dataStore.managedObjectContext];
+	FeedGroup *fg = [FeedGroup newGroup:type inContext:self.dataStore.managedObjectContext];
-	NSTreeNode *selection = [[self.dataStore selectedNodes] firstObject];
+	NSIndexPath *pth = [self indexPathForInsertAtNode:[[self.dataStore selectedNodes] firstObject]];
-	NSIndexPath *pth = nil;
+	[self.dataStore insertObject:fg atArrangedObjectIndexPath:pth];
 	
-	if (!selection) { // append to root
+	if (pth.length > 1) { // some subfolder and not root folder (has parent!)
-		pth = [NSIndexPath indexPathWithIndex:[self.dataStore arrangedObjects].childNodes.count]; // or 0 to append at front
-	} else if ([self.outlineView isItemExpanded:selection]) { // append to group (if open)
-		pth = [selection.indexPath indexPathByAddingIndex:0]; // or 'selection.childNodes.count' to append at end
-	} else { // append before / after selected item
-		pth = selection.indexPath;
-		// remove the two lines below to insert infront of selection (instead of after selection)
-		NSUInteger lastIdx = [pth indexAtPosition:pth.length - 1];
-		pth = [[pth indexPathByRemovingLastIndex] indexPathByAddingIndex:lastIdx + 1];
-	}
-	[self.dataStore insertObject:newItem atArrangedObjectIndexPath:pth];
-
-	if (pth.length > 2) { // some subfolder; not root folder (has parent!)
 		NSTreeNode *parentNode = [[self.dataStore arrangedObjects] descendantNodeAtIndexPath:pth].parentNode;
-		newItem.parent = parentNode.representedObject;
+		fg.parent = parentNode.representedObject;
 		[self restoreOrderingAndIndexPathStr:parentNode];
 	} else {
 		[self restoreOrderingAndIndexPathStr:[self.dataStore arrangedObjects]]; // .parent = nil
 	}
-	return newItem;
+	return fg;
 }
 
-/// Loop over all descendants and update @c sortIndex @c (FeedConfig) as well as all @c indexPath @c (Feed)
+/**
+ Index path will be selected as follow:
+ - @b root: append at end
+ - @b folder (expanded): append at front
+ - @b else: append after item.
+
+ @return indexPath where item will be inserted.
+ */
+- (NSIndexPath*)indexPathForInsertAtNode:(NSTreeNode*)node {
+	if (!node) { // append to root
+		return [NSIndexPath indexPathWithIndex:[self.dataStore arrangedObjects].childNodes.count]; // or 0 to append at front
+	} else if ([self.outlineView isItemExpanded:node]) { // append to group (if open)
+		return [node.indexPath indexPathByAddingIndex:0]; // or 'selection.childNodes.count' to append at end
+	} else { // append before / after selected item
+		NSIndexPath *pth = node.indexPath;
+		// remove the two lines below to insert infront of selection (instead of after selection)
+		NSUInteger lastIdx = [pth indexAtPosition:pth.length - 1];
+		return [[pth indexPathByRemovingLastIndex] indexPathByAddingIndex:lastIdx + 1];
+	}
+}
+
+/// Loop over all descendants and update @c sortIndex @c (FeedGroup) as well as all @c indexPath @c (Feed)
 - (void)restoreOrderingAndIndexPathStr:(NSTreeNode*)parent {
 	NSArray<NSTreeNode*> *children = parent.childNodes;
 	for (NSUInteger i = 0; i < children.count; i++) {
-		NSTreeNode *n = [children objectAtIndex:i];
+		FeedGroup *fg = [children objectAtIndex:i].representedObject;
-		FeedConfig *fc = n.representedObject;
+		if (fg.sortIndex != (int32_t)i)
-		// Re-calculate sort index for all affected parents
+			fg.sortIndex = (int32_t)i;
-		if (fc.sortIndex != (int32_t)i)
+		NSLog(@"%@ - %d", fg.name, fg.sortIndex);
-			fc.sortIndex = (int32_t)i;
+		[fg iterateSorted:NO overDescendantFeeds:^(Feed *feed, BOOL *cancel) {
-		// Re-calculate index path for all contained feed items
+			[feed calculateAndSetIndexPathString];
-		[fc iterateSorted:NO overDescendantFeeds:^(Feed *feed, BOOL *cancel) {
-			NSString *pthStr = [feed.config indexPathString];
-			if (![feed.indexPath isEqualToString:pthStr])
-				feed.indexPath = pthStr;
 		}];
 	}
 }
@@ -189,6 +192,7 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 #pragma mark - Dragging Support, Data Source Delegate
 
 
+/// Begin drag-n-drop operation by copying selected nodes to memory
 - (BOOL)outlineView:(NSOutlineView *)outlineView writeItems:(NSArray *)items toPasteboard:(NSPasteboard *)pboard {
 	[self.undoManager beginUndoGrouping];
 	[pboard declareTypes:[NSArray arrayWithObject:dragNodeType] owner:self];
@@ -197,6 +201,7 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 	return YES;
 }
 
+/// Finish drag-n-drop operation by saving changes to persistent store
 - (void)outlineView:(NSOutlineView *)outlineView draggingSession:(NSDraggingSession *)session endedAtPoint:(NSPoint)screenPoint operation:(NSDragOperation)operation {
 	[self.undoManager endUndoGrouping];
 	if (self.dataStore.managedObjectContext.hasChanges) {
@@ -209,6 +214,7 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 	self.currentlyDraggedNodes = nil;
 }
 
+/// Perform drag-n-drop operation, move nodes to new destination and update all indices
 - (BOOL)outlineView:(NSOutlineView *)outlineView acceptDrop:(id <NSDraggingInfo>)info item:(id)item childIndex:(NSInteger)index {
 	NSTreeNode *destParent = (item != nil ? item : [self.dataStore arrangedObjects]);
 	NSUInteger idx = (NSUInteger)index;
@@ -227,13 +233,12 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 	return YES;
 }
 
+/// Validate method whether items can be dropped at destination
 - (NSDragOperation)outlineView:(NSOutlineView *)outlineView validateDrop:(id <NSDraggingInfo>)info proposedItem:(id)item proposedChildIndex:(NSInteger)index {
-	FeedConfig *fc = [(NSTreeNode*)item representedObject];
+	NSTreeNode *parent = item;
-	if (index == -1 && fc.typ != GROUP) { // if drag is on specific item and that item isnt a group
+	if (index == -1 && [parent isLeaf]) { // if drag is on specific item and that item isnt a group
 		return NSDragOperationNone;
 	}
-	
-	NSTreeNode *parent = item;
 	while (parent != nil) {
 		for (NSTreeNode *node in self.currentlyDraggedNodes) {
 			if (parent == node)
@@ -248,10 +253,11 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 #pragma mark - Data Source Delegate
 
 
+/// Populate @c NSOutlineView data cells with core data object values.
 - (NSView *)outlineView:(NSOutlineView *)outlineView viewForTableColumn:(NSTableColumn *)tableColumn item:(id)item {
-	FeedConfig *f = [(NSTreeNode*)item representedObject];
+	FeedGroup *fg = [(NSTreeNode*)item representedObject];
-	BOOL isFeed = (f.typ == FEED);
+	BOOL isFeed = (fg.typ == FEED);
-	BOOL isSeperator = (f.typ == SEPARATOR);
+	BOOL isSeperator = (fg.typ == SEPARATOR);
 	BOOL isRefreshColumn = [tableColumn.identifier isEqualToString:@"RefreshColumn"];
 	
 	NSString *cellIdent = (isRefreshColumn ? @"cellRefresh" : (isSeperator ? @"cellSeparator" : @"cellFeed"));
@@ -259,12 +265,12 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 	NSTableCellView *cellView = [self.outlineView makeViewWithIdentifier:cellIdent owner:nil];
 	
 	if (isRefreshColumn) {
-		cellView.textField.stringValue = (!isFeed ? @"" : [f readableRefreshString]);
+		cellView.textField.stringValue = (isFeed && fg.refreshStr.length > 0 ? fg.refreshStr : @"");
 	} else if (isSeperator) {
 		return cellView; // the refresh cell is already skipped with the above if condition
 	} else {
-		cellView.textField.objectValue = f.name;
+		cellView.textField.objectValue = fg.name;
-		if (f.typ == GROUP) {
+		if (fg.typ == GROUP) {
 			cellView.imageView.image = [NSImage imageNamed:NSImageNameFolder];
 		} else {
 			// TODO: load icon
@@ -275,8 +281,10 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 			cellView.imageView.image = defaultRSSIcon;
 		}
 	}
-	if (isFeed) // also for refresh column
+	if (isFeed) {// also for refresh column
-		cellView.textField.textColor = (f.refreshNum == 0 ? [NSColor disabledControlTextColor] : [NSColor controlTextColor]);
+		BOOL feedDisbaled = (fg.refreshStr.length == 0 || [fg.refreshStr characterAtIndex:0] == '0');
+		cellView.textField.textColor = (feedDisbaled ? [NSColor disabledControlTextColor] : [NSColor controlTextColor]);
+	}
 	return cellView;
 }
 
@@ -284,6 +292,7 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 #pragma mark - Keyboard Commands: undo, redo, copy, enter
 
 
+/// Returning @c NO will result in a Action-Not-Available-Buzzer sound
 - (BOOL)respondsToSelector:(SEL)aSelector {
 	if (aSelector == @selector(undo:)) return [self.undoManager canUndo];
 	if (aSelector == @selector(redo:)) return [self.undoManager canRedo];
@@ -295,11 +304,12 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 		if (aSelector == @selector(copy:))
 			return YES;
 		// can edit only if selection is not a separator
-		return (((FeedConfig*)self.dataStore.selectedNodes.firstObject.representedObject).typ != SEPARATOR);
+		return (((FeedGroup*)self.dataStore.selectedNodes.firstObject.representedObject).typ != SEPARATOR);
 	}
 	return [super respondsToSelector:aSelector];
 }
 
+/// Perform undo operation and redraw UI & menu bar unread count
 - (void)undo:(id)sender {
 	[self.undoManager undo];
 	[self saveChanges];
@@ -307,6 +317,7 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 	[self.dataStore rearrangeObjects]; // update ordering
 }
 
+/// Perform redo operation and redraw UI & menu bar unread count
 - (void)redo:(id)sender {
 	[self.undoManager redo];
 	[self saveChanges];
@@ -314,10 +325,12 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 	[self.dataStore rearrangeObjects]; // update ordering
 }
 
+/// User pressed enter; open edit dialog for selected item.
 - (void)enterPressed:(id)sender {
-	[self openModalForSelection];
+	[self showModalForFeedGroup:self.dataStore.selectedObjects.firstObject isGroupEdit:YES]; // yes will be overwritten anyway
 }
 
+/// Copy human readable description of selected nodes to clipboard.
 - (void)copy:(id)sender {
 	NSMutableString *str = [[NSMutableString alloc] init];
 	NSUInteger count = self.dataStore.selectedNodes.count;

baRSS/Preferences/Feeds Tab/SettingsFeeds.xib

@@ -15,7 +15,7 @@
         </customObject>
         <customObject id="-1" userLabel="First Responder" customClass="FirstResponder"/>
         <customObject id="-3" userLabel="Application" customClass="NSObject"/>
-        <treeController mode="entity" entityName="FeedConfig" fetchPredicateFormat="parent == nil" automaticallyPreparesContent="YES" childrenKeyPath="children" leafKeyPath="type" id="JPf-gH-wxm"/>
+        <treeController mode="entity" entityName="FeedGroup" fetchPredicateFormat="parent == nil" automaticallyPreparesContent="YES" childrenKeyPath="children" leafKeyPath="type" id="JPf-gH-wxm"/>
         <customView id="zfc-Ie-Sdx" userLabel="View">
             <rect key="frame" x="0.0" y="0.0" width="320" height="327"/>
             <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>

baRSS/Preferences/General Tab/SettingsGeneral.m

@@ -25,8 +25,8 @@
 #import "BarMenu.h"
 #import "UserPrefs.h"
 #import "StoreCoordinator.h"
-#import <ServiceManagement/ServiceManagement.h>
 
+#import <ServiceManagement/ServiceManagement.h>
 
 @interface SettingsGeneral()
 @property (weak) IBOutlet NSPopUpButton *popupHttpApplication;
@@ -48,6 +48,7 @@
 
 #pragma mark - UI interaction with IBAction
 
+/// Run helper application to add thyself to startup items.
 - (IBAction)changeStartOnLogin:(NSButton *)sender {
 	// launchctl list | grep de.relikd
 	CFStringRef helperIdentifier = CFBridgingRetain(@"de.relikd.baRSS-Helper");

baRSS/Preferences/General Tab/UserPrefs.m

@@ -24,6 +24,7 @@
 
 @implementation UserPrefs
 
+/// @return @c YES if key is not set. Otherwise, return user defaults property from plist.
 + (BOOL)defaultYES:(NSString*)key {
 	if ([[NSUserDefaults standardUserDefaults] objectForKey:key] == NULL) {
 		return YES;
@@ -31,14 +32,17 @@
 	return [[NSUserDefaults standardUserDefaults] boolForKey:key];
 }
 
+/// @return @c NO if key is not set. Otherwise, return user defaults property from plist.
 + (BOOL)defaultNO:(NSString*)key {
 	return [[NSUserDefaults standardUserDefaults] boolForKey:key];
 }
 
+/// @return User configured custom browser. Or @c nil if not set yet. (which will fallback to default browser)
 + (NSString*)getHttpApplication {
 	return [[NSUserDefaults standardUserDefaults] stringForKey:@"defaultHttpApplication"];
 }
 
+/// Store custom browser bundle id to user defaults.
 + (void)setHttpApplication:(NSString*)bundleID {
 	[[NSUserDefaults standardUserDefaults] setObject:bundleID forKey:@"defaultHttpApplication"];
 }

baRSS/Preferences/ModalSheet.h

@@ -23,6 +23,8 @@
 #import <Cocoa/Cocoa.h>
 
 @interface ModalSheet : NSPanel
+@property (readonly) BOOL closeInitiated;
+
 + (instancetype)modalWithView:(NSView*)content;
 - (void)setDoneEnabled:(BOOL)accept;
 @end

baRSS/Preferences/ModalSheet.m

@@ -27,12 +27,22 @@
 @end
 
 @implementation ModalSheet
+@synthesize closeInitiated = _closeInitiated;
 
+/// User did click the 'Done' button.
 - (void)didTapDoneButton:(id)sender { [self closeWithResponse:NSModalResponseOK]; }
+/// User did click the 'Cancel' button.
 - (void)didTapCancelButton:(id)sender { [self closeWithResponse:NSModalResponseAbort]; }
+/// Manually disable 'Done' button if a task is still running.
 - (void)setDoneEnabled:(BOOL)accept { self.btnDone.enabled = accept; }
 
+/**
+ Called after user has clicked the 'Done' (Return) or 'Cancel' (Esc) button.
+ Flags controller as being closed @c .closeInitiated @c = @c YES.
+ And removes all subviews (clean up).
+ */
 - (void)closeWithResponse:(NSModalResponse)response {
+	_closeInitiated = YES;
 	// store modal view width and remove subviews to avoid _NSKeyboardFocusClipView issues
 	// first object is always the view of the modal dialog
 	CGFloat w = self.contentView.subviews.firstObject.frame.size.width;
@@ -41,6 +51,12 @@
 	[self.sheetParent endSheet:self returnCode:response];
 }
 
+
+/**
+ Designated initializer for @c ModalSheet.
+
+ @param content @c NSView will be displayed in dialog box. 'Done' and 'Cancel' button will be added automatically.
+ */
 + (instancetype)modalWithView:(NSView*)content {
 	static const int padWindow = 20;
 	static const int padButtons = 12;

baRSS/Preferences/Preferences.m

@@ -32,6 +32,7 @@
 
 @implementation Preferences
 
+/// Restore tab selection from previous session
 - (void)windowDidLoad {
 	[super windowDidLoad];
 	NSUInteger idx = (NSUInteger)[[NSUserDefaults standardUserDefaults] integerForKey:@"preferencesTab"];
@@ -40,6 +41,7 @@
 	[self tabClicked:self.window.toolbar.items[idx]];
 }
 
+/// Replace content view according to selected tab
 - (IBAction)tabClicked:(NSToolbarItem *)sender {
 	self.window.contentView = nil;
 	if ([sender.itemIdentifier isEqualToString:@"tabGeneral"]) {
@@ -59,7 +61,7 @@
 @end
 
 
-
+/// A window that does not respond to Cmd-C, Cmd-Z, Cmd-Shift-Z and Enter-pressed events.
 @interface NonRespondingWindow : NSWindow
 @end
 

baRSS/Status Bar Menu/BarMenu.h

@@ -24,5 +24,5 @@
 
 @interface BarMenu : NSObject <NSMenuDelegate>
 - (void)updateBarIcon;
-- (void)reloadUnreadCountAndUpdateBarIcon;
+- (void)asyncReloadUnreadCountAndUpdateBarIcon;
 @end

baRSS/Status Bar Menu/BarMenu.m

@@ -27,8 +27,9 @@
 #import "Preferences.h"
 #import "UserPrefs.h"
 #import "NSMenu+Ext.h"
-#import "Feed+Ext.h"
 #import "Constants.h"
+#import "Feed+Ext.h"
+#import "FeedGroup+Ext.h"
 
 
 @interface BarMenu()
@@ -52,15 +53,14 @@
 	// Unread counter
 	self.unreadCountTotal = 0;
 	[self updateBarIcon];
-	[self reloadUnreadCountAndUpdateBarIcon];
+	[self asyncReloadUnreadCountAndUpdateBarIcon];
 	
 	// Register for notifications
 	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(feedUpdated:) name:kNotificationFeedUpdated object:nil];
 	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(networkChanged:) name:kNotificationNetworkStatusChanged object:nil];
 	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(unreadCountChanged:) name:kNotificationTotalUnreadCountChanged object:nil];
-	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reloadUnreadCountAndUpdateBarIcon) name:kNotificationTotalUnreadCountReset object:nil];
+	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(asyncReloadUnreadCountAndUpdateBarIcon) name:kNotificationTotalUnreadCountReset object:nil];
-	[FeedDownload registerNetworkChangeNotification];
+	[FeedDownload registerNetworkChangeNotification]; // will call update scheduler
-	[FeedDownload performSelectorInBackground:@selector(scheduleNextUpdate:) withObject:[NSNumber numberWithBool:NO]];
 	return self;
 }
 
@@ -72,7 +72,7 @@
 #pragma mark - Update Menu Bar Icon -
 
 /// Regardless of current unread count, perform new core data fetch on total unread count and update icon.
-- (void)reloadUnreadCountAndUpdateBarIcon {
+- (void)asyncReloadUnreadCountAndUpdateBarIcon {
 	dispatch_async(dispatch_get_main_queue(), ^{
 		self.unreadCountTotal = [StoreCoordinator unreadCountForIndexPathString:nil];
 		[self updateBarIcon];
@@ -130,10 +130,10 @@
 		// update items only if menu is already open (e.g., during background update)
 		NSManagedObjectContext *moc = [StoreCoordinator createChildContext];
 		for (NSManagedObjectID *oid in notify.object) {
-			FeedConfig *fc = [moc objectWithID:oid];
+			Feed *feed = [moc objectWithID:oid];
-			NSMenu *menu = [self fixUnreadCountForSubmenus:fc];
+			NSMenu *menu = [self fixUnreadCountForSubmenus:feed];
 			if (!menu || menu.numberOfItems > 0)
-				[self rebuiltFeedItems:fc.feed inMenu:menu]; // deepest menu level, feed items
+				[self rebuiltFeedArticle:feed inMenu:menu]; // deepest menu level, feed items
 		}
 		[self.barItem.menu autoEnableMenuHeader:(self.unreadCountTotal > 0)]; // once per multi-feed update
 		[moc reset];
@@ -143,15 +143,14 @@
 /**
  Go through all parent menus and reset the menu title and unread count
 
- @param config Should contain a @c Feed object in @c config.feed.
+ @return @c NSMenu containing @c FeedArticle. Will be @c nil if user hasn't open the menu yet.
- @return @c NSMenu containing @c FeedItem. Will be @c nil if user hasn't open the menu yet.
  */
-- (nullable NSMenu*)fixUnreadCountForSubmenus:(FeedConfig*)config {
+- (nullable NSMenu*)fixUnreadCountForSubmenus:(Feed*)feed {
 	NSMenu *menu = self.barItem.menu;
-	for (FeedConfig *conf in [config allParents]) {
+	for (FeedGroup *parent in [feed.group allParents]) {
-		NSInteger offset = [menu feedConfigOffset];
+		NSInteger offset = [menu feedDataOffset];
-		NSMenuItem *item = [menu itemAtIndex:offset + conf.sortIndex];
+		NSMenuItem *item = [menu itemAtIndex:offset + parent.sortIndex];
-		NSInteger unread = [item setTitleAndUnreadCount:conf];
+		NSInteger unread = [item setTitleAndUnreadCount:parent];
 		menu = item.submenu;
 		if (!menu || menu.numberOfItems == 0)
 			return nil;
@@ -168,17 +167,17 @@
  @param feed Corresponding @c Feed to @c NSMenu.
  @param menu Deepest menu level which contains only feed items.
  */
-- (void)rebuiltFeedItems:(Feed*)feed inMenu:(NSMenu*)menu {
+- (void)rebuiltFeedArticle:(Feed*)feed inMenu:(NSMenu*)menu {
 	if (self.currentOpenMenu != menu) {
 		// if the menu isn't open, re-create it dynamically instead
 		menu.itemArray.firstObject.parentItem.submenu = [menu cleanInstanceCopy];
 	} else {
 		[menu removeAllItems];
 		[self insertDefaultHeaderForAllMenus:menu hasUnread:(feed.unreadCount > 0)];
-		for (FeedItem *fi in [feed sortedArticles]) {
+		for (FeedArticle *fa in [feed sortedArticles]) {
 			NSMenuItem *mi = [menu addItemWithTitle:@"" action:@selector(openFeedURL:) keyEquivalent:@""];
 			mi.target = self;
-			[mi setFeedItem:fi];
+			[mi setFeedArticle:fa];
 		}
 	}
 }
@@ -219,12 +218,12 @@
 /// Lazy populate system bar menus when needed.
 - (BOOL)menu:(NSMenu*)menu updateItem:(NSMenuItem*)item atIndex:(NSInteger)index shouldCancel:(BOOL)shouldCancel {
 	id obj = [self.readContext objectWithID:[self.objectIDsForMenu objectAtIndex:(NSUInteger)index]];
-	if ([obj isKindOfClass:[FeedConfig class]]) {
+	if ([obj isKindOfClass:[FeedGroup class]]) {
-		[item setFeedConfig:obj];
+		[item setFeedGroup:obj];
-		if ([(FeedConfig*)obj typ] == FEED)
+		if ([(FeedGroup*)obj typ] == FEED)
 			[item setTarget:self action:@selector(openFeedURL:)];
-	} else if ([obj isKindOfClass:[FeedItem class]]) {
+	} else if ([obj isKindOfClass:[FeedArticle class]]) {
-		[item setFeedItem:obj];
+		[item setFeedArticle:obj];
 		[item setTarget:self action:@selector(openFeedURL:)];
 	}
 	
@@ -243,7 +242,7 @@
 - (void)finalizeMenu:(NSMenu*)menu object:(id)obj {
 	NSInteger unreadCount = self.unreadCountTotal; // if parent == nil
 	if ([menu isFeedMenu]) {
-		unreadCount = [(FeedItem*)obj feed].unreadCount;
+		unreadCount = ((FeedArticle*)obj).feed.unreadCount;
 	} else if (![menu isMainMenu]) {
 		unreadCount = [menu coreDataUnreadCount];
 	}
@@ -326,6 +325,7 @@
 - (void)preferencesClosed:(id)sender {
 	[[NSNotificationCenter defaultCenter] removeObserver:self name:NSWindowWillCloseNotification object:self.prefWindow.window];
 	self.prefWindow = nil;
+	[FeedDownload scheduleNextUpdateForced:NO];
 }
 
 /**
@@ -340,7 +340,7 @@
  */
 - (void)updateAllFeeds:(NSMenuItem*)sender {
 	// TODO: Disable 'update all' menu item during update?
-	[FeedDownload scheduleNextUpdate:YES];
+	[FeedDownload scheduleNextUpdateForced:YES];
 }
 
 /**
@@ -354,11 +354,11 @@
 	
 	NSManagedObjectContext *moc = [StoreCoordinator createChildContext];
 	[sender iterateSorted:YES inContext:moc overDescendentFeeds:^(Feed *feed, BOOL *cancel) {
-		for (FeedItem *i in [feed sortedArticles]) { // TODO: open oldest articles first?
+		for (FeedArticle *fa in [feed sortedArticles]) { // TODO: open oldest articles first?
 			if (maxItemCount <= 0) break;
-			if (i.unread && i.link.length > 0) {
+			if (fa.unread && fa.link.length > 0) {
-				[urls addObject:[NSURL URLWithString:i.link]];
+				[urls addObject:[NSURL URLWithString:fa.link]];
-				i.unread = NO;
+				fa.unread = NO;
 				feed.unreadCount -= 1;
 				self.unreadCountTotal -= 1;
 				maxItemCount -= 1;
@@ -389,7 +389,7 @@
 /**
  Called when user clicks on a single feed item or the feed group.
 
- @param sender A menu item containing either a @c FeedItem or a @c FeedConfig objectID.
+ @param sender A menu item containing either a @c FeedArticle or a @c FeedGroup objectID.
  */
 - (void)openFeedURL:(NSMenuItem*)sender {
 	NSManagedObjectID *oid = sender.representedObject;
@@ -398,14 +398,14 @@
 	NSString *url = nil;
 	NSManagedObjectContext *moc = [StoreCoordinator createChildContext];
 	id obj = [moc objectWithID:oid];
-	if ([obj isKindOfClass:[FeedConfig class]]) {
+	if ([obj isKindOfClass:[FeedGroup class]]) {
-		url = [[(FeedConfig*)obj feed] link];
+		url = ((FeedGroup*)obj).feed.link;
-	} else if ([obj isKindOfClass:[FeedItem class]]) {
+	} else if ([obj isKindOfClass:[FeedArticle class]]) {
-		FeedItem *item = obj;
+		FeedArticle *fa = obj;
-		url = [item link];
+		url = fa.link;
-		if (item.unread) {
+		if (fa.unread) {
-			item.unread = NO;
+			fa.unread = NO;
-			item.feed.unreadCount -= 1;
+			fa.feed.unreadCount -= 1;
 			self.unreadCountTotal -= 1;
 			[self updateBarIcon];
 			[StoreCoordinator saveContext:moc andParent:YES];

baRSS/Status Bar Menu/NSMenu+Ext.h

@@ -32,7 +32,7 @@
 - (BOOL)isMainMenu;
 - (BOOL)isFeedMenu;
 - (MenuItemTag)scope;
-- (NSInteger)feedConfigOffset;
+- (NSInteger)feedDataOffset;
 - (NSInteger)coreDataUnreadCount;
 // Modify menu
 - (void)replaceSeparatorStringsWithActualSeparator;

baRSS/Status Bar Menu/NSMenu+Ext.m

@@ -70,8 +70,8 @@
 	return ScopeGroup;
 }
 
-/// @return Index offset of the first Core Data feed item (may be separator), skipping default header and main menu header.
+/// @return Index offset of the first core data feed item (may be separator), skipping default header and main menu header.
-- (NSInteger)feedConfigOffset {
+- (NSInteger)feedDataOffset {
 	for (NSInteger i = 0; i < self.numberOfItems; i++) {
 		if ([[[self itemAtIndex:i] representedObject] isKindOfClass:[NSManagedObjectID class]])
 			return i;
@@ -79,7 +79,7 @@
 	return 0;
 }
 
-/// Perform Core Data fetch request and return unread count for all descendent items.
+/// Perform core data fetch request and return unread count for all descendent items.
 - (NSInteger)coreDataUnreadCount {
 	NSUInteger loc = [self.title rangeOfString:@"."].location;
 	NSString *path = nil;

baRSS/Status Bar Menu/NSMenuItem+Ext.h

@@ -26,11 +26,11 @@ static NSString *kSeparatorItemTitle = @"---SEPARATOR---";
 
 /// @c NSMenuItem options that are assigned to the @c tag attribute.
 typedef NS_OPTIONS(NSInteger, MenuItemTag) {
-	/// Item visible at the very first menu level
+	/// Item visible at the very first menu level @c (StatusBar)
 	ScopeGlobal = 2,
-	/// Item visible at each grouping, e.g., multiple feeds in one group
+	/// Item visible at each group, e.g., multiple feeds in one group
 	ScopeGroup = 4,
-	/// Item visible at the deepest menu level (@c FeedItem elements and header)
+	/// Item visible at the deepest menu level @c (FeedArticle)
 	ScopeFeed = 8,
 	///
 	TagPreferences = (1 << 4),
@@ -44,16 +44,16 @@ typedef NS_OPTIONS(NSInteger, MenuItemTag) {
 	TagMaskType = 0xFFF0,
 };
 
-@class FeedConfig, Feed, FeedItem;
+@class FeedGroup, Feed, FeedArticle;
 
 @interface NSMenuItem (Feed)
 + (NSMenuItem*)itemWithTitle:(NSString*)title action:(SEL)selector target:(id)target tag:(MenuItemTag)tag;
 - (NSMenuItem*)alternateWithTitle:(NSString*)title;
 - (void)setTarget:(id)target action:(SEL)selector;
 
-- (void)setFeedConfig:(FeedConfig*)config;
+- (void)setFeedGroup:(FeedGroup*)group;
-- (void)setFeedItem:(FeedItem*)item;
+- (void)setFeedArticle:(FeedArticle*)article;
-- (NSInteger)setTitleAndUnreadCount:(FeedConfig*)config;
+- (NSInteger)setTitleAndUnreadCount:(FeedGroup*)group;
 
 - (void)iterateSorted:(BOOL)ordered inContext:(NSManagedObjectContext*)moc overDescendentFeeds:(void(^)(Feed *feed, BOOL *cancel))block;
 @end

baRSS/Status Bar Menu/NSMenuItem+Ext.m

@@ -25,6 +25,7 @@
 #import "StoreCoordinator.h"
 #import "DrawImage.h"
 #import "UserPrefs.h"
+#import "FeedGroup+Ext.h"
 
 /// User preferences for displaying menu items
 typedef NS_ENUM(char, DisplaySetting) {
@@ -83,42 +84,42 @@ typedef NS_ENUM(char, DisplaySetting) {
  
  @return Number of unread items. (@b warning: May return @c 0 if visibility is disabled in @c UserPrefs)
  */
-- (NSInteger)setTitleAndUnreadCount:(FeedConfig*)config {
+- (NSInteger)setTitleAndUnreadCount:(FeedGroup*)fg {
 	NSInteger uCount = 0;
-	if (config.typ == FEED && [UserPrefs defaultYES:@"feedUnreadCount"]) {
+	if (fg.typ == FEED && [UserPrefs defaultYES:@"feedUnreadCount"]) {
-		uCount = config.feed.unreadCount;
+		uCount = fg.feed.unreadCount;
-	} else if (config.typ == GROUP && [UserPrefs defaultYES:@"groupUnreadCount"]) {
+	} else if (fg.typ == GROUP && [UserPrefs defaultYES:@"groupUnreadCount"]) {
 		uCount = [self.submenu coreDataUnreadCount];
 	}
-	self.title = (uCount > 0 ? [NSString stringWithFormat:@"%@ (%ld)", config.name, uCount] : config.name);
+	self.title = (uCount > 0 ? [NSString stringWithFormat:@"%@ (%ld)", fg.name, uCount] : fg.name);
 	return uCount;
 }
 
 /**
- Fully configures a Separator item OR group item OR feed item. (but not @c FeedItem item)
+ Fully configures a Separator item OR group item OR feed item. (but not @c FeedArticle item)
  */
-- (void)setFeedConfig:(FeedConfig*)config {
+- (void)setFeedGroup:(FeedGroup*)fg {
-	self.representedObject = config.objectID;
+	self.representedObject = fg.objectID;
-	if (config.typ == SEPARATOR) {
+	if (fg.typ == SEPARATOR) {
 		self.title = kSeparatorItemTitle;
 	} else {
-		self.submenu = [self.menu submenuWithIndex:config.sortIndex isFeed:(config.typ == FEED)];
+		self.submenu = [self.menu submenuWithIndex:fg.sortIndex isFeed:(fg.typ == FEED)];
-		[self setTitleAndUnreadCount:config]; // after submenu is set
+		[self setTitleAndUnreadCount:fg]; // after submenu is set
-		if (config.typ == FEED) {
+		if (fg.typ == FEED) {
-			[self configureAsFeed:config];
+			[self configureAsFeed:fg];
 		} else {
-			[self configureAsGroup:config];
+			[self configureAsGroup:fg];
 		}
 	}
 }
 
 /**
- Configure menu item to be used as a container for @c FeedItem entries (incl. feed icon).
+ Configure menu item to be used as a container for @c FeedArticle entries (incl. feed icon).
  */
-- (void)configureAsFeed:(FeedConfig*)config {
+- (void)configureAsFeed:(FeedGroup*)fg {
 	self.tag = ScopeFeed;
-	self.toolTip = config.feed.subtitle;
+	self.toolTip = fg.feed.subtitle;
-	self.enabled = (config.feed.items.count > 0);
+	self.enabled = (fg.feed.articles.count > 0);
 	// set icon
 	dispatch_async(dispatch_get_main_queue(), ^{
 		static NSImage *defaultRSSIcon;
@@ -131,9 +132,9 @@ typedef NS_ENUM(char, DisplaySetting) {
 /**
  Configure menu item to be used as a container for multiple feeds.
  */
-- (void)configureAsGroup:(FeedConfig*)config {
+- (void)configureAsGroup:(FeedGroup*)fg {
 	self.tag = ScopeGroup;
-	self.enabled = (config.children.count > 0);
+	self.enabled = (fg.children.count > 0);
 	// set icon
 	dispatch_async(dispatch_get_main_queue(), ^{
 		static NSImage *groupIcon;
@@ -146,50 +147,50 @@ typedef NS_ENUM(char, DisplaySetting) {
 }
 
 /**
- Populate @c NSMenuItem based on the attributes of a @c FeedItem.
+ Populate @c NSMenuItem based on the attributes of a @c FeedArticle.
  */
-- (void)setFeedItem:(FeedItem*)item {
+- (void)setFeedArticle:(FeedArticle*)fa {
-	self.title = item.title;
+	self.title = fa.title;
 	self.tag = ScopeFeed;
-	self.enabled = (item.link.length > 0);
+	self.enabled = (fa.link.length > 0);
-	self.state = (item.unread ? NSControlStateValueOn : NSControlStateValueOff);
+	self.state = (fa.unread ? NSControlStateValueOn : NSControlStateValueOff);
-	self.representedObject = item.objectID;
+	self.representedObject = fa.objectID;
 	//mi.toolTip = item.abstract;
 	// TODO: Do regex during save, not during display. Its here for testing purposes ...
-	if (item.abstract.length > 0) {
+	if (fa.abstract.length > 0) {
 		NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"<[^>]*>" options:kNilOptions error:nil];
-		self.toolTip = [regex stringByReplacingMatchesInString:item.abstract options:kNilOptions range:NSMakeRange(0, item.abstract.length) withTemplate:@""];
+		self.toolTip = [regex stringByReplacingMatchesInString:fa.abstract options:kNilOptions range:NSMakeRange(0, fa.abstract.length) withTemplate:@""];
 	}
 }
 
 #pragma mark - Helper -
 
 /**
- @return @c FeedConfig object if @c representedObject contains a valid @c NSManagedObjectID.
+ @return @c FeedGroup object if @c representedObject contains a valid @c NSManagedObjectID.
  */
-- (FeedConfig*)requestConfig:(NSManagedObjectContext*)moc {
+- (FeedGroup*)requestGroup:(NSManagedObjectContext*)moc {
 	if (!self.representedObject || ![self.representedObject isKindOfClass:[NSManagedObjectID class]])
 		return nil;
-	FeedConfig *config = [moc objectWithID:self.representedObject];
+	FeedGroup *fg = [moc objectWithID:self.representedObject];
-	if (![config isKindOfClass:[FeedConfig class]])
+	if (![fg isKindOfClass:[FeedGroup class]])
 		return nil;
-	return config;
+	return fg;
 }
 
 /**
- Perform @c block on every @c FeedConfig in the items menu or any of its submenues.
+ Perform @c block on every @c FeedGroup in the items menu or any of its submenues.
 
  @param ordered Whether order matters or not. If all items are processed anyway, pass @c NO for a speedup.
  @param block Set cancel to @c YES to stop enumeration early.
  */
 - (void)iterateSorted:(BOOL)ordered inContext:(NSManagedObjectContext*)moc overDescendentFeeds:(void(^)(Feed*,BOOL*))block {
 	if (self.parentItem) {
-		[[self.parentItem requestConfig:moc] iterateSorted:ordered overDescendantFeeds:block];
+		[[self.parentItem requestGroup:moc] iterateSorted:ordered overDescendantFeeds:block];
 	} else {
 		for (NSMenuItem *item in self.menu.itemArray) {
-			FeedConfig *fc = [item requestConfig:moc];
+			FeedGroup *fg = [item requestGroup:moc];
-			if (fc != nil) { // All groups and feeds; Ignore default header
+			if (fg != nil) { // All groups and feeds; Ignore default header
-				if (![fc iterateSorted:ordered overDescendantFeeds:block])
+				if (![fg iterateSorted:ordered overDescendantFeeds:block])
 					return;
 			}
 		}

baRSS/StoreCoordinator.h

@@ -22,16 +22,13 @@
 
 #import <Foundation/Foundation.h>
 #import "DBv1+CoreDataModel.h"
-#import "FeedConfig+Ext.h"
-
-@class RSParsedFeed;
 
 @interface StoreCoordinator : NSObject
 // Managing contexts
 + (NSManagedObjectContext*)createChildContext;
 + (void)saveContext:(NSManagedObjectContext*)context andParent:(BOOL)flag;
 // Feed update
-+ (NSArray<FeedConfig*>*)getListOfFeedsThatNeedUpdate:(BOOL)forceAll inContext:(NSManagedObjectContext*)moc;
++ (NSArray<Feed*>*)getListOfFeedsThatNeedUpdate:(BOOL)forceAll inContext:(NSManagedObjectContext*)moc;
 + (NSDate*)nextScheduledUpdate;
 // Feed display
 + (NSInteger)unreadCountForIndexPathString:(NSString*)str;

baRSS/StoreCoordinator.m

@@ -22,16 +22,24 @@
 
 #import "StoreCoordinator.h"
 #import "AppHook.h"
+#import "Feed+Ext.h"
+
 #import <RSXML/RSXML.h>
 
 @implementation StoreCoordinator
 
 #pragma mark - Managing contexts -
 
+/**
+ @return The application main persistent context.
+ */
 + (NSManagedObjectContext*)getMainContext {
 	return [(AppHook*)NSApp persistentContainer].viewContext;
 }
 
+/**
+ New child context with @c NSMainQueueConcurrencyType and without undo manager.
+ */
 + (NSManagedObjectContext*)createChildContext {
 	NSManagedObjectContext *context = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
 	[context setParentContext:[self getMainContext]];
@@ -40,6 +48,11 @@
 	return context;
 }
 
+/**
+ Commit changes and perform save operation on @c context.
+
+ @param flag If @c YES save any parent context (recursive).
+ */
 + (void)saveContext:(NSManagedObjectContext*)context andParent:(BOOL)flag {
 	// Performs the save action for the application, which is to send the save: message to the application's managed object context. Any encountered errors are presented to the user.
 	if (![context commitEditing]) {
@@ -57,14 +70,16 @@
 
 #pragma mark - Feed Update -
 
-+ (NSArray<FeedConfig*>*)getListOfFeedsThatNeedUpdate:(BOOL)forceAll inContext:(NSManagedObjectContext*)moc {
+/**
-	// TODO: Get Feed instead of FeedConfig
+ List of @c Feed items that need to be updated. Scheduled time is now (or in past).
-	NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName: FeedConfig.entity.name];
+
+ @param forceAll If @c YES get a list of all @c Feed regardless of schedules time.
+ */
++ (NSArray<Feed*>*)getListOfFeedsThatNeedUpdate:(BOOL)forceAll inContext:(NSManagedObjectContext*)moc {
+	NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName: Feed.entity.name];
 	if (!forceAll) {
 		// when fetching also get those feeds that would need update soon (now + 30s)
-		fr.predicate = [NSPredicate predicateWithFormat:@"type = %d AND scheduled <= %@", FEED, [NSDate dateWithTimeIntervalSinceNow:+30]];
+		fr.predicate = [NSPredicate predicateWithFormat:@"meta.scheduled <= %@", [NSDate dateWithTimeIntervalSinceNow:+30]];
-	} else {
-		fr.predicate = [NSPredicate predicateWithFormat:@"type = %d", FEED];
 	}
 	NSError *err;
 	NSArray *result = [moc executeFetchRequest:fr error:&err];
@@ -72,8 +87,11 @@
 	return result;
 }
 
+/**
+ @return @c NSDate of next (earliest) feed update. May be @c nil.
+ */
 + (NSDate*)nextScheduledUpdate {
-	// Always get context first, or 'FeedConfig.entity.name' may not be available on app start
+	// Always get context first, or 'FeedMeta.entity.name' may not be available on app start
 	NSManagedObjectContext *moc = [self getMainContext];
 	NSExpression *exp = [NSExpression expressionForFunction:@"min:"
 												  arguments:@[[NSExpression expressionForKeyPath:@"scheduled"]]];
@@ -82,8 +100,7 @@
 	[expDesc setExpression:exp];
 	[expDesc setExpressionResultType:NSDateAttributeType];
 	
-	NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName: FeedConfig.entity.name];
+	NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName: FeedMeta.entity.name];
-	fr.predicate = [NSPredicate predicateWithFormat:@"type = %d", FEED];
 	[fr setResultType:NSDictionaryResultType];
 	[fr setPropertiesToFetch:@[expDesc]];
 	
@@ -95,8 +112,13 @@
 
 #pragma mark - Feed Display -
 
+/**
+ Perform core data fetch request with sum over all unread feeds matching @c str.
+
+ @param str A dot separated string of integer index parts.
+ */
 + (NSInteger)unreadCountForIndexPathString:(NSString*)str {
-	// Always get context first, or 'FeedConfig.entity.name' may not be available on app start
+	// Always get context first, or 'Feed.entity.name' may not be available on app start
 	NSManagedObjectContext *moc = [self getMainContext];
 	NSExpression *exp = [NSExpression expressionForFunction:@"sum:"
 												  arguments:@[[NSExpression expressionForKeyPath:@"unreadCount"]]];
@@ -117,10 +139,16 @@
 	return [fetchResults.firstObject[@"totalUnread"] integerValue];
 }
 
+/**
+ Get sorted list of @c ObjectIDs for either @c FeedGroup or @c FeedArticle.
+
+ @param parent Either @c ObjectID or actual object. Or @c nil for root folder.
+ @param flag If @c YES request list of @c FeedArticle instead of @c FeedGroup
+ */
 + (NSArray*)sortedObjectIDsForParent:(id)parent isFeed:(BOOL)flag inContext:(NSManagedObjectContext*)moc {
 //	NSManagedObjectContext *moc = [self getMainContext];
-	NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName: (flag ? FeedItem.entity : FeedConfig.entity).name];
+	NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName: (flag ? FeedArticle.entity : FeedGroup.entity).name];
-	fr.predicate = [NSPredicate predicateWithFormat:(flag ? @"feed.config = %@" : @"parent = %@"), parent];
+	fr.predicate = [NSPredicate predicateWithFormat:(flag ? @"feed.group = %@" : @"parent = %@"), parent];
 	fr.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"sortIndex" ascending:!flag]];
 	[fr setResultType:NSManagedObjectIDResultType];
 	
@@ -130,30 +158,24 @@
 	return fetchResults;
 }
 
-//+ (void)addToSortIndex:(int)num start:(int)index parent:(FeedConfig*)config inContext:(NSManagedObjectContext*)moc {
-//	NSBatchUpdateRequest *ur = [[NSBatchUpdateRequest alloc] initWithEntityName: FeedConfig.entity.name];
-//	ur.predicate = [NSPredicate predicateWithFormat:@"parent = %@ AND sortIndex >= %d", config, index];
-//	ur.propertiesToUpdate = @{@"sortIndex": [NSExpression expressionWithFormat: @"sortIndex + %d", num]};
-//	ur.resultType = NSUpdatedObjectsCountResultType;//NSUpdatedObjectIDsResultType;//NSStatusOnlyResultType;
-//	NSError *err;
-//	NSBatchUpdateResult *result = [moc executeRequest:ur error:&err];
-//	if (err) NSLog(@"%@", err);
-//	NSLog(@"Result: %@", result.result);
-//	//[NSManagedObjectContext mergeChangesFromRemoteContextSave:@{NSUpdatedObjectsKey : result.result} intoContexts:@[moc]];
-//}
-
 #pragma mark - Restore Sound State -
 
+/**
+ Delete all @c Feed items where @c group @c = @c NULL.
+ */
 + (void)deleteUnreferencedFeeds {
 	NSManagedObjectContext *moc = [self getMainContext];
-	NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName:Feed.entity.name];
+	NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName: Feed.entity.name];
-	fr.predicate = [NSPredicate predicateWithFormat:@"config = NULL"];
+	fr.predicate = [NSPredicate predicateWithFormat:@"group = NULL"];
 	NSBatchDeleteRequest *bdr = [[NSBatchDeleteRequest alloc] initWithFetchRequest:fr];
 	NSError *err;
 	[moc executeRequest:bdr error:&err];
 	if (err) NSLog(@"%@", err);
 }
 
+/**
+ Iterate over all @c Feed and re-calculate @c unreadCount, @c articleCount and @c indexPath.
+ */
 + (void)restoreFeedCountsAndIndexPaths {
 	NSManagedObjectContext *moc = [self getMainContext];
 	NSError *err;
@@ -161,16 +183,13 @@
 	if (err) NSLog(@"%@", err);
 	[moc performBlock:^{
 		for (Feed *feed in result) {
-			int16_t totalCount = (int16_t)feed.items.count;
+			int16_t totalCount = (int16_t)feed.articles.count;
-			int16_t unreadCount = (int16_t)[[feed.items valueForKeyPath:@"@sum.unread"] integerValue];
+			int16_t unreadCount = (int16_t)[[feed.articles valueForKeyPath:@"@sum.unread"] integerValue];
 			if (feed.articleCount != totalCount)
 				feed.articleCount = totalCount;
 			if (feed.unreadCount != unreadCount)
 				feed.unreadCount = unreadCount; // remember to update global total unread count
-			
+			[feed calculateAndSetIndexPathString];
-			NSString *pathStr = [feed.config indexPathString];
-			if (![feed.indexPath isEqualToString:pathStr])
-				feed.indexPath = pathStr;
 		}
 	}];
 }