iOS-Patterns

Adapter

What is it ?

Its a wrapper around class giving it a new interface.

When use it ?

• Converting interface of a class into another interface that clients expect without modifying their source code.

You have to change the library in the project. Moving from google maps to apple maps.

• Class you attend to use have very old interface. Example "dispatch_after" coded below.

@interface Timer : NSObject
+(void)dispatchAfter:(double)seconds block:(void (^)())block;
@end

@implementation Timer
+(void)dispatchAfter:(double)seconds block:(void (^)())block {
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, seconds * NSEC_PER_SEC), dispatch_get_main_queue(), task);
}
@end

[Timer dispatchAfter:10 block:^{
    NSLog(@"Print");
}];
    
              VS
    
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 10 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
    NSLog(@"Print");
});

More info :

https://sourcemaking.com/design_patterns/adapter

http://www.tutorialspoint.com/design_pattern/adapter_pattern.htm

http://www.oodesign.com/adapter-pattern.html

https://en.wikipedia.org/wiki/Adapter_pattern

Decorator

What is it ?

When use it ?

[Timer new];

More info :