Refactor deserialization to support format config

Add a remoteSiteFormat property to CoreManager to enable setting the format in the app delegate in the same way as remoteSiteURL.  This patch also lays the foundation for other deserializers by removing a hardcoded reference to JSON in CoreResource, although it falls back to JSON if no format is specified.

CoreDeserializer.m

@@ -29,38 +29,31 @@ - (id) initWithSource:(id)sourceObj andResourceClass:(Class)clazz {
 
 
 - (void) main {
-    // Use format to change deserialization class and convert serialized string into resources
-    Class newClass = [resourceClass performSelector:@selector(deserializerClassForFormat:) withObject:[self format]];
-    if (newClass != nil) {
-
-        // Get Core Manager from resource class if it hasn't been defined yet
-        if (coreManager == nil)
-            coreManager = [[resourceClass performSelector:@selector(coreManager)] retain];
-
-        // Create "scratchpad" object context; we will merge this context into the main context once deserialization is complete
-        managedObjectContext = [[coreManager newContext] retain];
-        [[NSNotificationCenter defaultCenter] addObserver:self 
-            selector:@selector(contextDidSave:) 
-            name:NSManagedObjectContextDidSaveNotification 
-            object:managedObjectContext];
-
-        resources = [[self resourcesFromString:[self sourceString]] retain];
-
-        // Attempt to save object context; if there's an error, it will be placed in the CoreResult (which is sent to the target)
-        [managedObjectContext save:&error];
-
-        [self performSelectorOnMainThread:@selector(notify) withObject:nil waitUntilDone:NO];
-
-        // Remove context save observer
-        [[NSNotificationCenter defaultCenter] removeObserver:self 
-            name:NSManagedObjectContextDidSaveNotification object:managedObjectContext];
-
-        return;
-    }
-
-    // Log error if level is high enough
-    if (error != nil && coreManager.logLevel > 3)
-        NSLog(@"CoreDeserializer error: %@", [error description]);
+  // Get Core Manager from resource class if it hasn't been defined yet
+  if (coreManager == nil)
+    coreManager = [[resourceClass performSelector:@selector(coreManager)] retain];  
+
+  // Create "scratchpad" object context; we will merge this context into the main context once deserialization is complete
+  managedObjectContext = [[coreManager newContext] retain];
+  [[NSNotificationCenter defaultCenter] addObserver:self 
+      selector:@selector(contextDidSave:) 
+      name:NSManagedObjectContextDidSaveNotification 
+      object:managedObjectContext];
+
+  resources = [[self resourcesFromString:[self sourceString]] retain];
+
+  // Attempt to save object context; if there's an error, it will be placed in the CoreResult (which is sent to the target)
+  [managedObjectContext save:&error];
+
+  [self performSelectorOnMainThread:@selector(notify) withObject:nil waitUntilDone:NO];
+
+  // Remove context save observer
+  [[NSNotificationCenter defaultCenter] removeObserver:self 
+      name:NSManagedObjectContextDidSaveNotification object:managedObjectContext];            
+
+  // Log error if level is high enough
+  if (error != nil && coreManager.logLevel > 3)
+      NSLog(@"CoreDeserializer error: %@", [error description]);
 }
 
 

CoreManager.h

@@ -17,6 +17,7 @@
     NSOperationQueue *deserialzationQueue;
 
     NSString *remoteSiteURL;
+    NSString *remoteSiteFormat;
 
     // Default setting for whether or not to get data from within the bundle (instead of performing remote HTTP requests)
     BOOL useBundleRequests;
@@ -42,6 +43,7 @@
 @property (nonatomic, retain) NSOperationQueue *deserialzationQueue;
 
 @property (nonatomic, retain) NSString *remoteSiteURL;
+@property (nonatomic, retain) NSString *remoteSiteFormat;
 @property (nonatomic, assign) BOOL useBundleRequests;
 @property (nonatomic, assign) float bundleRequestDelay;
 

CoreManager.m

@@ -16,7 +16,7 @@ @implementation CoreManager
 
 @synthesize persistentStoreCoordinator, managedObjectContext, managedObjectModel;
 @synthesize requestQueue, deserialzationQueue;
-@synthesize remoteSiteURL, useBundleRequests, bundleRequestDelay, defaultDateParser;
+@synthesize remoteSiteURL, remoteSiteFormat, useBundleRequests, bundleRequestDelay, defaultDateParser;
 @synthesize entityDescriptions, modelProperties, modelRelationships, modelAttributes;
 @synthesize logLevel;
 
@@ -54,6 +54,9 @@ - (id) initWithOptions:(NSDictionary*)options {
 
         logLevel = 1;
 
+        if (remoteSiteFormat == nil)
+          remoteSiteFormat = @"json";
+
         // ===== Core Data initialization ===== //
 
         // Create primary managed object model
@@ -170,6 +173,7 @@ - (void)dealloc {
     [modelRelationships release];
 
     [remoteSiteURL release];
+    [remoteSiteFormat release];
 
     [managedObjectContext release];
     [managedObjectModel release];

CoreResource.h

@@ -31,6 +31,7 @@ typedef enum _Action {
 + (BOOL) useBundleRequests;
 
 + (NSString*) remoteSiteURL;
++ (NSString*) remoteSiteFormat;
 + (NSString*) remoteCollectionName;
 + (NSString*) remoteURLForCollectionAction:(Action)action;
 + (NSString*) remoteURLForResource:(id)resourceId action:(Action)action;
@@ -55,7 +56,7 @@ typedef enum _Action {
 + (NSDateFormatter*) dateParser;
 + (NSDateFormatter*) dateParserForField:(NSString*)field;
 
-+ (Class) deserializerClassForFormat:(NSString*)format;
++ (Class) deserializerClass;
 //+ (id) resourceCollectionFromJSONCollection:(id)jsonCollection withParent:(id)parent;
 //+ (id) resourcePropertiesFromJSONElement:(id)jsonElement withParent:(id)parent;
 

CoreResource.m

@@ -32,6 +32,10 @@ + (NSString*) remoteSiteURL {
     return [[self coreManager] remoteSiteURL];
 }
 
++ (NSString*) remoteSiteFormat {
+    return [[self coreManager] remoteSiteFormat];
+}
+
 + (NSString*) remoteCollectionName {
     return [[[NSStringFromClass(self) deCamelizeWith:@"_"] substringFromIndex:1] stringByAppendingString:@"s"];
 }
@@ -103,8 +107,8 @@ + (NSDateFormatter*) dateParserForField:(NSString*)field {
     return [self dateParser];
 }
 
-+ (Class) deserializerClassForFormat:(NSString*)format {
-    return NSClassFromString($S(@"Core%@Deserializer", [format uppercaseString]));
++ (Class) deserializerClass {
+    return NSClassFromString($S(@"Core%@Deserializer", [[self remoteSiteFormat] uppercaseString]));
 }
 
 /**
@@ -603,7 +607,7 @@ + (void) findRemote:(id)resourceId {
 
 + (void) findRemote:(id)resourceId andNotify:(id)del withSelector:(SEL)selector {
     CoreRequest *request = [[[CoreRequest alloc] initWithURL:
-        [CoreUtils URLWithSite:[self remoteURLForResource:resourceId action:Read] andFormat:@"json" andParameters:nil]] autorelease];
+        [CoreUtils URLWithSite:[self remoteURLForResource:resourceId action:Read] andFormat:[self remoteSiteFormat] andParameters:nil]] autorelease];
     request.delegate = self;
     request.didFinishSelector = @selector(findRemoteDidFinish:);
     request.didFailSelector = @selector(findRemoteDidFail:);
@@ -632,7 +636,7 @@ + (void) findAllRemote:(id)parameters {
 
 + (void) findAllRemote:(id)parameters andNotify:(id)del withSelector:(SEL)selector {
     CoreRequest *request = [[[CoreRequest alloc] initWithURL:
-        [CoreUtils URLWithSite:[self remoteURLForCollectionAction:Read] andFormat:@"json" andParameters:parameters]] autorelease];
+        [CoreUtils URLWithSite:[self remoteURLForCollectionAction:Read] andFormat:[self remoteSiteFormat] andParameters:parameters]] autorelease];
     request.delegate = self;
     request.didFinishSelector = @selector(findRemoteDidFinish:);
     request.didFailSelector = @selector(findRemoteDidFail:);
@@ -653,7 +657,7 @@ + (void) findAllRemote:(id)parameters andNotify:(id)del withSelector:(SEL)select
 
 + (void) findRemoteDidFinish:(CoreRequest*)request {
     // Create and enqueue deserializer in non-blocking thread
-    CoreDeserializer* deserializer = [[CoreJSONDeserializer alloc] initWithSource:request andResourceClass:self];
+    CoreDeserializer* deserializer = [[[self deserializerClass] alloc] initWithSource:request andResourceClass:self];
     deserializer.target = request.coreDelegate;
     deserializer.action = request.coreSelector;
     [[[self coreManager] deserialzationQueue] addOperation:deserializer];