Created the SearchResultsModel protocol and made YahooSearchResultsMo…

…del and FlickrSearchResultsModel conform to this new protocol.

I also fixed a bug in YahooXMLResponse's XPath queries.

Classes/AppDelegate.m

@@ -7,37 +7,8 @@
 #import "AppDelegate.h"
 #import "SearchTableViewController.h"
 #import "SearchPhotosViewController.h"
-#import "YahooSearchResultsModel.h"
-#import "FlickrSearchResultsModel.h"
-#import "App.h"
 #import "Three20/Three20.h"
 
-SearchService CurrentSearchService = SearchServiceDefault;
-SearchResponseFormat CurrentSearchResponseFormat = SearchResponseFormatDefault;
-
-id CreateSearchModel(SearchService service, SearchResponseFormat responseFormat)
-{
-    id model = nil;
-    switch ( service ) {
-        case SearchServiceYahoo:
-            model = [[[YahooSearchResultsModel alloc] initWithResponseFormat:responseFormat] autorelease];
-            break;
-        case SearchServiceFlickr:
-            model = [[[FlickrSearchResultsModel alloc] initWithResponseFormat:responseFormat] autorelease];
-            break;
-        default:
-            [NSException raise:@"CurrentSearchService unknown" format:nil];
-            break;
-    }
-    return model;
-}
-
-id CreateSearchModelWithCurrentSettings(void)
-{
-    return CreateSearchModel(CurrentSearchService, CurrentSearchResponseFormat);
-}
-
-
 @implementation AppDelegate
 
 @synthesize window;

Classes/FlickrSearchResultsModel.h

@@ -6,7 +6,7 @@
 //
 
 #import "Three20/Three20.h"
-#import "App.h"
+#import "SearchResultsModel.h"
 
 @class URLModelResponse;
 
@@ -17,17 +17,13 @@
  *  See the description of YahooSearchResultsModel.
  *
  */
-@interface FlickrSearchResultsModel : TTURLRequestModel
+@interface FlickrSearchResultsModel : TTURLRequestModel <SearchResultsModel>
 {
     URLModelResponse *responseProcessor;
     NSString *searchTerms;
     NSUInteger page;
 }
 
-@property (nonatomic, readonly) NSArray *results;   // When your TTTableViewDataSource needs data to display, it should use this method to acquire the parsed SearchResult domain objects.
-@property (nonatomic, readonly) NSUInteger totalResultsAvailableOnServer;
-@property (nonatomic, retain) NSString *searchTerms;
-
-- (id)initWithResponseFormat:(SearchResponseFormat)responseFormat;
+// The designated initializer is defined in the SearchResultsModel protocol.
 
 @end

Classes/FlickrSearchResultsModel.m

@@ -9,7 +9,6 @@
 #import "FlickrJSONResponse.h"
 #import "FlickrXMLResponse.h"
 #import "GTMNSDictionary+URLArguments.h"
-#import "App.h"
 
 const static NSUInteger kFlickrBatchSize = 16;   // The number of results to pull down with each request to the server.
 
@@ -61,7 +60,7 @@ - (void)load:(TTURLRequestCachePolicy)cachePolicy more:(BOOL)more
                                 @"flickr.photos.search", @"method",
                                 searchTerms, @"text",
                                 @"url_m,url_t", @"extras",
-                                @"43f122b1a7fef3db2328bd75b38da08d", @"api_key", // TODO comment this out
+                                @"43f122b1a7fef3db2328bd75b38da08d", @"api_key", // I am providing my own API key as a convenience because I'm trusting you not to use it for evil.
                                 [responseProcessor format], @"format",
                                 [NSString stringWithFormat:@"%lu", (unsigned long)page], @"page",
                                 batchSize, @"per_page",

Classes/SearchPhotosViewController.m

@@ -4,7 +4,7 @@
 
 #import "SearchPhotosViewController.h"
 #import "SearchResultsPhotoSource.h"
-#import "App.h"
+#import "SearchResultsModel.h"
 
 @implementation SearchPhotosViewController
 
@@ -21,12 +21,16 @@ - (void)doSearch
 {
     NSLog(@"Searching for %@", queryField.text);
 
-    // Configure the photo source with the user's search terms
-    // and load the new data.
-    // NOTE: the compiler warning here is wrong, it just doesn't know
-    //       that photoSource forwards to the model.
-    [photoSource setSearchTerms:[queryField text]];
     [queryField resignFirstResponder];
+
+    // Configure the photo source with the user's search terms.
+    // NOTE: I have to explicitly cast the photoSource to the SearchResultsModel
+    //       protocol because otherwise the compiler will issue a warning
+    //       (because the compiler doesn't know that the photoSource forwards
+    //       to a SearchResultsModel at runtime)
+    [(id<SearchResultsModel>)photoSource setSearchTerms:[queryField text]];
+
+    // Load the new data
     [photoSource load:TTURLRequestCachePolicyDefault more:NO];
 
     // Display the updated photoSource.

Classes/SearchResultsModel.h

@@ -0,0 +1,54 @@
+/*
+ *  SearchResultsModel.h
+ *
+ *  Created by Keith Lazuka on 7/25/09.
+ *
+ */
+
+#import "Three20/Three20.h"
+
+/*
+ *  NOTE: this is where you can switch the web service between Flickr and Yahoo
+ *        and between using the JSON and XML response processors.
+ *        All you need to do is set SearchServiceDefault and 
+ *        SearchResponseFormatDefault to the appropriate value.
+ *
+ */
+typedef enum {
+    SearchServiceYahoo,
+    SearchServiceFlickr,
+    SearchServiceDefault = SearchServiceYahoo
+} SearchService;
+extern SearchService CurrentSearchService;
+
+typedef enum {
+    SearchResponseFormatJSON,
+    SearchResponseFormatXML,
+    SearchResponseFormatDefault = SearchResponseFormatXML
+} SearchResponseFormat;
+extern SearchResponseFormat CurrentSearchResponseFormat;
+
+#pragma mark -
+
+/*
+ *      SearchResultsModel
+ *
+ *  This protocol is intended for TTModels that represent a remote search service.
+ *  
+ */
+@protocol SearchResultsModel <TTModel>
+
+@property (nonatomic, readonly) NSArray *results;                           // A list of domain objects constructed by the model after parsing the web service's HTTP response. In this case, it is a list of SearchResult objects.
+@property (nonatomic, readonly) NSUInteger totalResultsAvailableOnServer;   // The total number of results available on the server (but not necessarily downloaded) for the current model configuration's search query.
+@property (nonatomic, retain) NSString *searchTerms;                        // The keywords that will be submitted to the web service in order to do the actual image search (e.g. "green apple")
+
+- (id)initWithResponseFormat:(SearchResponseFormat)responseFormat;          // The designated initializer
+
+@end
+
+#pragma mark -
+
+// Factory methods for instantiating a functioning SearchResultsModel.
+id<SearchResultsModel> CreateSearchModelWithCurrentSettings(void);
+id<SearchResultsModel> CreateSearchModel(SearchService service, SearchResponseFormat responseFormat);
+

Classes/SearchResultsModel.m

@@ -0,0 +1,34 @@
+//
+//  SearchResultsModel.m
+//
+//  Created by Keith Lazuka on 7/25/09.
+//
+
+#import "SearchResultsModel.h"
+#import "YahooSearchResultsModel.h"
+#import "FlickrSearchResultsModel.h"
+
+SearchService CurrentSearchService = SearchServiceDefault;
+SearchResponseFormat CurrentSearchResponseFormat = SearchResponseFormatDefault;
+
+id<SearchResultsModel> CreateSearchModel(SearchService service, SearchResponseFormat responseFormat)
+{
+    id<SearchResultsModel> model = nil;
+    switch ( service ) {
+        case SearchServiceYahoo:
+            model = [[[YahooSearchResultsModel alloc] initWithResponseFormat:responseFormat] autorelease];
+            break;
+        case SearchServiceFlickr:
+            model = [[[FlickrSearchResultsModel alloc] initWithResponseFormat:responseFormat] autorelease];
+            break;
+        default:
+            [NSException raise:@"CurrentSearchService unknown" format:nil];
+            break;
+    }
+    return model;
+}
+
+id<SearchResultsModel> CreateSearchModelWithCurrentSettings(void)
+{
+    return CreateSearchModel(CurrentSearchService, CurrentSearchResponseFormat);
+}

Classes/SearchResultsPhotoSource.h

@@ -7,7 +7,7 @@
 
 #import "Three20/Three20.h"
 
-@class YahooSearchResultsModel;
+@protocol SearchResultsModel;
 
 /*
  *      SearchResultsPhotoSource
@@ -28,15 +28,15 @@
  */
 @interface SearchResultsPhotoSource : NSObject <TTPhotoSource>
 {
-    YahooSearchResultsModel *model;
+    id<SearchResultsModel> *model;
 
     // Backing storage for TTPhotoSource properties.
     NSString *albumTitle;
     int totalNumberOfPhotos;    
 }
 
-- (id)initWithModel:(YahooSearchResultsModel *)theModel;    // Designated initializer.
+- (id)initWithModel:(id<SearchResultsModel>)theModel;    // Designated initializer.
 
-- (id<TTModel>)underlyingModel;     // The model to which this PhotoSource forwards in order to conform to the TTModel protocol.
+- (id<SearchResultsModel>)underlyingModel;     // The model to which this PhotoSource forwards in order to conform to the TTModel protocol.
 
 @end

Classes/SearchResultsTableDataSource.m

@@ -7,6 +7,7 @@
 
 #import "SearchResultsTableDataSource.h"
 #import "SearchResult.h"
+#import "SearchResultsModel.h"
 
 @implementation SearchResultsTableDataSource
 
@@ -19,7 +20,7 @@ - (void)tableViewDidLoadModel:(UITableView *)tableView
 
     // Construct an object that is suitable for the table view system
     // from each SearchResult domain object that we retrieve from the TTModel.
-    for (SearchResult *result in [self.model results])
+    for (SearchResult *result in [(id<SearchResultsModel>)self.model results])
         [self.items addObject:[TTTableImageItem itemWithText:result.title
                                                     imageURL:result.thumbnailURL
                                                 defaultImage:[UIImage imageNamed:@"photo_placeholder.png"]

Classes/SearchTableViewController.m

@@ -4,7 +4,7 @@
 
 #import "SearchTableViewController.h"
 #import "SearchResultsTableDataSource.h"
-#import "App.h"
+#import "SearchResultsModel.h"
 
 @implementation SearchTableViewController
 
@@ -63,7 +63,7 @@ - (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
     // Configure our TTModel with the user's search terms
     // and tell the TTModelViewController to reload.
     [searchBar resignFirstResponder];
-    [self.model setSearchTerms:[searchBar text]]; // TODO I guess I'm going to need to create a model base class, or at least a protocol.
+    [(id<SearchResultsModel>)self.model setSearchTerms:[searchBar text]];
     [self reload];
     [self.tableView scrollToTop:YES];
 }

Classes/YahooSearchResultsModel.h

@@ -6,6 +6,7 @@
 //
 
 #import "Three20/Three20.h"
+#import "SearchResultsModel.h"
 
 @class URLModelResponse;
 
@@ -40,15 +41,13 @@
  *  directly into the YahooSearchResultsModel class.
  *
  */
-@interface YahooSearchResultsModel : TTURLRequestModel
+@interface YahooSearchResultsModel : TTURLRequestModel <SearchResultsModel>
 {
     URLModelResponse *responseProcessor;
     NSString *searchTerms;
     NSUInteger recordOffset;
 }
 
-@property (nonatomic, readonly) NSArray *results;   // When your TTTableViewDataSource needs data to display, it should use this method to acquire the parsed SearchResult domain objects.
-@property (nonatomic, readonly) NSUInteger totalResultsAvailableOnServer;
-@property (nonatomic, retain) NSString *searchTerms;
+// The designated initializer is defined in the SearchResultsModel protocol.
 
 @end

Classes/YahooSearchResultsModel.m

@@ -9,7 +9,6 @@
 #import "YahooJSONResponse.h"
 #import "YahooXMLResponse.h"
 #import "GTMNSDictionary+URLArguments.h"
-#import "App.h"
 
 const static NSUInteger kYahooBatchSize = 16;   // The number of results to pull down with each request to the server.
 

Classes/YahooXMLResponse.m

@@ -31,7 +31,7 @@ - (NSError*)request:(TTURLRequest*)request processResponse:(NSHTTPURLResponse*)r
     NSArray *bigImageWidths = [root nodesForXPath:@"//foo:Result/foo:Width" error:&error];
     NSArray *bigImageHeights = [root nodesForXPath:@"//foo:Result/foo:Height" error:&error];
     NSArray *thumbnailURLs = [root nodesForXPath:@"//foo:Result/foo:Thumbnail/foo:Url" error:&error];
-    totalObjectsAvailableOnServer = [[[[root nodesForXPath:@"foo:ResultSet[@totalResultsAvailable]" error:&error] lastObject] stringValue] integerValue];
+    totalObjectsAvailableOnServer = [[[[root nodesForXPath:@"//foo:ResultSet/@totalResultsAvailable" error:&error] lastObject] stringValue] integerValue];
 
     NSAssert1(!error, @"XML Parse error: %@", error);
     NSAssert([titles count] == [bigImageURLs count] && [titles count] == [thumbnailURLs count], 
@@ -43,8 +43,8 @@ - (NSError*)request:(TTURLRequest*)request processResponse:(NSHTTPURLResponse*)r
         result.title = [[titles objectAtIndex:i] stringValue];
         result.bigImageURL = [[bigImageURLs objectAtIndex:i] stringValue];
         result.thumbnailURL = [[thumbnailURLs objectAtIndex:i] stringValue];
-        result.bigImageSize = CGSizeMake([[bigImageWidths objectAtIndex:i] intValue], 
-                                         [[bigImageHeights objectAtIndex:i] intValue]);
+        result.bigImageSize = CGSizeMake([[[bigImageWidths objectAtIndex:i] stringValue] intValue], 
+                                         [[[bigImageHeights objectAtIndex:i] stringValue] intValue]);
         [self.objects addObject:result];
     }
 

TTRemoteExamples.xcodeproj/project.pbxproj

@@ -32,6 +32,7 @@
 		539A1C4D101B50480085BC76 /* FlickrJSONResponse.m in Sources */ = {isa = PBXBuildFile; fileRef = 539A1C4A101B50480085BC76 /* FlickrJSONResponse.m */; };
 		539A1C4E101B50480085BC76 /* FlickrSearchResultsModel.m in Sources */ = {isa = PBXBuildFile; fileRef = 539A1C4C101B50480085BC76 /* FlickrSearchResultsModel.m */; };
 		539A1D2B101B69550085BC76 /* FlickrXMLResponse.m in Sources */ = {isa = PBXBuildFile; fileRef = 539A1D2A101B69550085BC76 /* FlickrXMLResponse.m */; };
+		539A1DCB101BCAE30085BC76 /* SearchResultsModel.m in Sources */ = {isa = PBXBuildFile; fileRef = 539A1DCA101BCAE30085BC76 /* SearchResultsModel.m */; };
 		539C36E30FD6A99D00117201 /* GTMNSString+URLArguments.m in Sources */ = {isa = PBXBuildFile; fileRef = 539C36E00FD6A99D00117201 /* GTMNSString+URLArguments.m */; };
 		539C36E40FD6A99D00117201 /* GTMNSDictionary+URLArguments.m in Sources */ = {isa = PBXBuildFile; fileRef = 539C36E20FD6A99D00117201 /* GTMNSDictionary+URLArguments.m */; };
 		53CDB8D01018B56800AE0B64 /* SearchResult.m in Sources */ = {isa = PBXBuildFile; fileRef = 53CDB8CF1018B56800AE0B64 /* SearchResult.m */; };
@@ -110,9 +111,10 @@
 		539A1C4A101B50480085BC76 /* FlickrJSONResponse.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = FlickrJSONResponse.m; sourceTree = "<group>"; };
 		539A1C4B101B50480085BC76 /* FlickrSearchResultsModel.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = FlickrSearchResultsModel.h; sourceTree = "<group>"; };
 		539A1C4C101B50480085BC76 /* FlickrSearchResultsModel.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = FlickrSearchResultsModel.m; sourceTree = "<group>"; };
-		539A1CB2101B5D540085BC76 /* App.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = App.h; sourceTree = "<group>"; };
 		539A1D29101B69550085BC76 /* FlickrXMLResponse.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = FlickrXMLResponse.h; sourceTree = "<group>"; };
 		539A1D2A101B69550085BC76 /* FlickrXMLResponse.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = FlickrXMLResponse.m; sourceTree = "<group>"; };
+		539A1DC9101BC9A10085BC76 /* SearchResultsModel.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SearchResultsModel.h; sourceTree = "<group>"; };
+		539A1DCA101BCAE30085BC76 /* SearchResultsModel.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SearchResultsModel.m; sourceTree = "<group>"; };
 		539C36DE0FD6A99D00117201 /* GTMDefines.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = GTMDefines.h; sourceTree = "<group>"; };
 		539C36DF0FD6A99D00117201 /* GTMNSString+URLArguments.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "GTMNSString+URLArguments.h"; sourceTree = "<group>"; };
 		539C36E00FD6A99D00117201 /* GTMNSString+URLArguments.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "GTMNSString+URLArguments.m"; sourceTree = "<group>"; };
@@ -157,7 +159,6 @@
 				53D976520FFA57D600E62B9A /* Table Stuff */,
 				1D3623240D0F684500981E51 /* AppDelegate.h */,
 				1D3623250D0F684500981E51 /* AppDelegate.m */,
-				539A1CB2101B5D540085BC76 /* App.h */,
 			);
 			path = Classes;
 			sourceTree = "<group>";
@@ -330,6 +331,8 @@
 				53CDB8CF1018B56800AE0B64 /* SearchResult.m */,
 				53F0E6440FD716AA00523DB2 /* URLModelResponse.h */,
 				53F0E6450FD716AA00523DB2 /* URLModelResponse.m */,
+				539A1DC9101BC9A10085BC76 /* SearchResultsModel.h */,
+				539A1DCA101BCAE30085BC76 /* SearchResultsModel.m */,
 			);
 			name = Model;
 			sourceTree = "<group>";
@@ -444,6 +447,7 @@
 				539A1C4D101B50480085BC76 /* FlickrJSONResponse.m in Sources */,
 				539A1C4E101B50480085BC76 /* FlickrSearchResultsModel.m in Sources */,
 				539A1D2B101B69550085BC76 /* FlickrXMLResponse.m in Sources */,
+				539A1DCB101BCAE30085BC76 /* SearchResultsModel.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};