Abstract Factory method pattern - ios

Question

I have gone through couple of video and blog tuts online. Felt like i understood everything, however still struggling to implement the Abstract factory pattern. Here is my requirement:
I have a User class which should give a user object.
There are two types of users in my application for e.g Service Provider (Provider) and Service receiver (Consumer).
There are some common properties between these two types of users like name, email id , mobile number etc. For Provider type there will be some extra properties.
Provider types could be of for e.g. TaxiDriver or Restaurant etc.
I want to implement Abstract factory and factory method pattern for this user class so that the application can be decoupled from the User model and whenever the application wants an User of type Provider or Consumer it should get the right object.
What I tried so far:
AbstracUserProtocol.h
#protocol AbstractUserProtocol
#required
#property(nonatomic, strong) id delegate;
#property(nonatomic, readonly, getter=isExist) BOOL exist;
#property (nonatomic, strong) NSString *name;
#property (nonatomic, strong) NSString *emailID;
#property (nonatomic, assign) NSInteger phoneNumber;
-(void)saveUserData;
-(void)retrievUserData;
#end
AbstractUser.h
#interface AbstractUser : NSObject <AbstractUserProtocol>
-(id)initWithType:(UserType)usrType;
#end
AbstractUser.m
#implementation AbstractUser
#synthesize delegate, exist, name, emailID, phoneNumber;
-(id)initWithType:(UserType)usrType
{
self = nil;
if (usrType == kConsumer) {
self = [Consumer alloc]init];
}
else if (usrType == kProvider) {
self = [ProviderFactory alloc] initWithServiceType:TaxiService];
}
return self;
}
-(void)saveUserData {
[NSException raise:NSInternalInconsistencyException
format:#"You have not implemented %# in %#",
NSStringFromSelector(_cmd), NSStringFromClass([self class])];
}
-(void)retrievUserData {
}
#end
Now created two subclasses Consumer and ProviderFactory from AbstractUser class.
Consumer.h
#interface Consumer : AbstractUser
#property (nonatomic, strong) NSString *address;
#end
ProviderFactory.h
#interface ProviderFactory : AbstractUser
-(id)initWithServiceType:(ServiceType)srvType;
#property(nonatomic, strong) NSString *ownerDetails;
#end
So whenever in future if my application want to support another business user like Taxi and Restaurant type then I just have to create a class and init through ProviderFactory class.
Is my approach correct for the abstract Factory pattern? Appreciate any guidance.

Answer 1

Based on your follow up question, I edited the answer.
I'm not entirely sure you need to use AbstractFactory for what you are trying to accomplish. The basics of AbstractFactory is that it allows you to
provide an interface for creating families of related or dependent
objects without specifying their concrete classes (Gamma et al.)
Take this example from Design Patterns: Elements of Reusable Object-Oriented Software by Gamma et al. Let's say you are creating a toolkit to build user interfaces for a document editor. You may have a bunch of widget objects like scrollers, buttons, toolbars, etc. But you may want to later add a different look-and-feel to the document editor. So then you can use AbstractFactory to provide an interface to create all of the widget products (i.e. createScrollbar, createButtons, etc.) but then to change the look-and-feel, you subclass the abstract class and override the methods so that say, createScrollbar returns a scrollbar that has a 3-D effect. In another case, you subclass the abstract class to create a pink scrollbar. The options are endless, and since your client code doesn't care what the scrollbar looks like (all the client cares about is whether it scrolls text or not), you can easily add future looks-and-feels without touching the client code.
In your case, the client cares what kind of AbstractUser it is getting because in some cases it needs a Customer and in some cases a Provider. So either way, your client code would have to be changed if in the future you added a new kind of user.
That said, I think the best approach for you would be to just create an abstract base class of User and then subclass it and add the user-specific properties to the subclass. Here is an example of what I mean.
AbstractUser.h
#import <Foundation/Foundation.h>
#interface AbstractUser : NSObject
#property(nonatomic, strong) id delegate;
#property(nonatomic, readonly, getter=isExist) BOOL exist;
#property (nonatomic, strong) NSString *name;
#property (nonatomic, strong) NSString *emailID;
#property (nonatomic, assign) NSInteger phoneNumber;
#end
Consumer.h
#import "AbstractUser.h"
#interface Consumer : AbstractUser
#property (strong, nonatomic) NSString *address;
#end
ViewController.m
#import "ViewController.h"
#import "Consumer.h"
#import "Provider.h"
#interface ViewController ()
#property (strong, nonatomic) Consumer *consumer;
#property (strong, nonatomic) Provider *provider;
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
_consumer = [[Consumer alloc] init];
_provider = [[Provider alloc] init];
self.consumer.name = #"Jason";
self.consumer.address = #"some address";
self.provider.name = #"Stack Overflow";
#end