ROADServices.md

#Services

Services implements access of application-wide objects via Service Locator acting as a gathering and decorating point. Public interface exposed in RFServiceProvider.

##Registering a service

Registering a service requires 2 simple steps:

• Add category to RFServiceProvider with a getter for the service.

@interface SFServiceProvider (SampleService)
- (id<SampleServiceInterface>)watchListService;
@end	

SampleServiceInterface is a placeholder for any abstraction protocol to the service.

• Annotate getter with RFService attribute specifying service class.

RF_ATTRIBUTE(RFService, serviceClass = [SampleService class])
- (id<SampleServiceInterface>)watchListService;

##Example

Logger shared instance created using Service Locator looks like:

#import <ROAD/ROADServices.h>
#import "RFLogger.h"

@interface RFServiceProvider (LoggingService)

RF_ATTRIBUTE(RFService, serviceClass = [RFLogger class])
+ (id<RFLogging>)logger;

@end

And used as:

id <RFLogging> logger = [RFServiceProvider logger];

##Dependencies

Services are build on top of Attributes to specify service class for each specific case.

RFService attribute with single serviceClass property serves for this. Class object as a parameter value is passed.