ios - The correct realization of the adapter pattern in objective c -

i need create data manager app without hardcoding on 1 file format, if change way of saving data - can easily. purposes choose adapter pattern.

i have datamanager class wrote general methods making data store it.

@protocol datamanagerprotocol @required - (void) readfile; - (void) savefile; @end  @interface datamanager : nsobject {     nsmutablearray *items;     nsmutablestring *destpath; }  // many different methods  @end 

than have datafilemanager there method storing data in 1 specific format:

@interface datafilemanager : nsobject - (void) saveplist; - (void) readplist; @end  @implementation datafilemanager  - (void) saveplist {     nslog(@"the plist file saved."); }  -(void) readplist {     nslog(@"the plist file readed."); }  @end 

and have dataadapter convert interfaces:

#import <foundation/foundation.h> #import "datafilemanager.h" #import "datamanager.h"  @interface dataadapter : nsobject <datamanagerprotocol> {     @private datafilemanager *_datafilemanager; }  @property (nonatomic, strong) datafilemanager *datafilemanager; - (id) initwithdatafilemanager:(datafilemanager*) adaptee; @end  @implementation dataadapter  @synthesize datafilemanager = _datafilemanager;  - (id) initwithdatafilemanager:(datafilemanager *) adaptee {     self = [super self];     _datafilemanager = adaptee;     return self; }  - (void) savefile {     [_datafilemanager saveplist]; }  - (void) readfile {     [_datafilemanager readplist]; }  @end 

so in datamanager file write method:

- (void) savethetestfile:(id)foradapter {     [foradapter savefile]; } 

and using this:

datafilemanager *datafilemanager = [[datafilemanager alloc] init]; dataadapter *dataadapter = [[dataadapter alloc] initwithdatafilemanager:datafilemanager]; [self savethetestfile:dataadapter]; 

it works, believe wrong here - there way make more simple? don't use arc , need release lot of filemanagers - it's not good, believe. totally confused in methods. maybe can give more interesting , simple realization of pattern case? thank you!

another solution use category on datamanager class defined inside implementation file of datafilemanager class.

here example how should like:

//class datafilemanager's implementation @implementation datamanager (datafilemanager_adapter) // methods allow datafilemanager connect datamanager // methods datafilemanager can use calculate values dependent on both datamanager //  , datafilemanager @end  @implementation datafilemanager // datafilemanager's methods @end  

the classical approach create third intermediary class have done but, in objective-c, categories eliminate need. adapter interfaces in objective-c, using categories.