diff -r 000000000000 -r a59acc683080 Source/Game-Persistence.m
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Source/Game-Persistence.m	Thu May 29 15:04:06 2008 -0700
@@ -0,0 +1,115 @@
+//
+//  Game-Persistence.m
+//  GeekGameBoard
+//
+//  Created by Jens Alfke on 3/16/08.
+//  Copyright 2008 __MyCompanyName__. All rights reserved.
+//
+
+#import "Game-Persistence.h"
+
+
+static NSDictionary* parseURLFields( NSURL* url );
+
+
+@implementation Game (Persistence)
+
+
+static NSMutableDictionary *sPersistentGames;
+
+
+- (id) initWithCoder: (NSCoder*)decoder
+{
+    self = [self init];
+    if( self ) {
+        _players = [[decoder decodeObjectForKey: @"players"] mutableCopy];
+        _states  = [[decoder decodeObjectForKey: @"states"] mutableCopy];
+        _moves   = [[decoder decodeObjectForKey: @"moves"] mutableCopy];
+        self.currentTurn = self.maxTurn;
+    }
+    return self;
+}
+
+
+- (void) encodeWithCoder: (NSCoder*)coder
+{
+    [coder encodeObject: _players forKey: @"players"];
+    [coder encodeObject: _states  forKey: @"states"];
+    [coder encodeObject: _moves   forKey: @"moves"];
+}
+
+
+- (NSURL*) asURL
+{
+    return [NSURL URLWithString: 
+            [NSString stringWithFormat: @"game:type=%@&id=%@&turn=%u&move=%@",
+             [[self class] identifier], _uniqueID, self.currentTurn,_moves.lastObject]];
+}
+
+
++ (Game*) gameWithURL: (NSURL*)url
+{
+    if( 0 != [@"game" caseInsensitiveCompare: url.scheme] )
+        return nil;
+    NSDictionary *fields = parseURLFields(url);
+    NSString *type = [fields objectForKey: @"type"];
+    NSString *uuid = [fields objectForKey: @"id"];
+    int turn = [[fields objectForKey: @"turn"] intValue];
+    if( !type || !uuid || turn<=0 )
+        return nil;
+    
+    Game *game = [sPersistentGames objectForKey: uuid];
+    if( game ) {
+        if( ![type isEqualToString: [[game class] identifier]] )
+            return nil;
+    } else if( turn == 1 ) {
+        Class gameClass = NSClassFromString( [type stringByAppendingString: @"Game"] );
+        if( ! gameClass || ! [gameClass isSubclassOfClass: [Game class]] )
+            return nil;
+        game = [[gameClass alloc] initWithUniqueID: uuid];
+        [game setNumberOfPlayers: 2];
+        if( ! sPersistentGames )
+            sPersistentGames = [[NSMutableDictionary alloc] init];
+        [sPersistentGames setObject: game forKey: uuid];
+        [game release];
+    }
+    return game;
+}
+
+
+- (BOOL) addMoveFromURL: (NSURL*)url
+{
+    NSDictionary *fields = parseURLFields(url);
+    NSString *uuid = [fields objectForKey: @"id"];
+    NSString *move = [fields objectForKey: @"move"];
+    int turn = [[fields objectForKey: @"turn"] intValue];
+    return [uuid isEqualToString: self.uniqueID]
+        && turn==self.currentTurn
+        && move.length > 0
+        && [self applyMoveString: move];
+}
+
+
+
+@end
+
+
+
+static NSDictionary* parseURLFields( NSURL* url )
+{
+    // Parse the URL into key-value pairs:
+    NSMutableDictionary *fields = [NSMutableDictionary dictionary];
+    for( NSString *field in [url.resourceSpecifier componentsSeparatedByString: @"&"] ) {
+        NSRange e = [field rangeOfString: @"="];
+        NSString *key, *value;
+        if( e.length>0 ) {
+            key = [field substringToIndex: e.location];
+            value = [field substringFromIndex: NSMaxRange(e)];
+        } else {
+            key= field;
+            value = @"";
+        }
+        [fields setObject: value forKey: key];
+    }
+    return fields;
+}