Design Pattern - Objective-C - MVC Model View Controller -

hi read tutorials around web on mvc , read topics on here. think got concept of mvc i'm not sure of implementation.

i've tried apply simple program, window have label , button. button increase counter , label shows value of it.

i tried in 2 different ways.

in first case ( example works ) melt view , controller. said, example works, want guys tell me if it's correct implementation mvc or it's not following right design.

the second example has model view , controller 3 separated class, example doesnt work because v , c import itself, love guys tell me i'm doing wrong.

first version: model, view-controller

//model.h #import <foundation/foundation.h>  @interface model : nsobject {     int _counter; }  -(void)setcounter:(int)valuecounter; -(int)getcounter; -(void)increasecounter; @end  //model.m #import "model.h" @implementation model {}  -(void)setcounter:(int)valuecounter { _counter = valuecounter; } -(int)getcounter { return _counter; } -(void)increasecounter{ _counter ++; } @end   //viewcontroller.h #import <uikit/uikit.h> #import "model.h"  @interface viewcontroller : uiviewcontroller {     iboutlet uibutton *_button;     iboutlet uilabel *_label;     model *mymodel; }  -(ibaction)send:(id)sender; @end  //viewcontroller.m #import "viewcontroller.h" @interface viewcontroller () @end  @implementation viewcontroller - (void)viewdidload {     [super viewdidload];      mymodel = [[model alloc]init];     _label.text = [nsstring stringwithformat:@"%d",[mymodel getcounter]]; }  - (void)didreceivememorywarning { [super didreceivememorywarning]; }  - (ibaction)send:(id)sender{     [mymodel increasecounter];     _label.text = [nsstring stringwithformat:@"%d",[mymodel getcounter]]; }  @end 

is way correct pattern mvc ? code works, before start more complex apps want make sure code in way. how app, way of mvc. bad? good? how change or fix it?

second version: model, view, controller separated

----> model

//model.h #import <foundation/foundation.h>  @interface model : nsobject {     int _count; }  -(void)setcount:(int)value; -(int)getcount; -(void)increasecount;  @end  //model.m #import "model.h"  @implementation model  -(void)setcount:(int)value { _count = value; } -(int)getcount { return _count; } -(void)increasecount { _count = _count++; }  @end 

----> view

//view.h #import <uikit/uikit.h> #import "controller.h"  @interface viewcontroller : uiviewcontroller{     iboutlet uilabel *label;     iboutlet uibutton *button;     controller *mycontroller; }  @end  //view.m #import "viewcontroller.h" #import "controller.h"  @interface viewcontroller () @end  @implementation viewcontroller  - (void)viewdidload {     [super viewdidload];     mycontroller = [[controller alloc]init]; }  - (void)didreceivememorywarning { [super didreceivememorywarning]; }   -(ibaction)pressbutton:(id)sender{     label.text = [nsstring stringwithformat:@"%d",[mycontroller actionincrease]]; }  @end 

----> controller

//controller.m #import <foundation/foundation.h>  @class "model.h" @class  "viewcontroller.h"  @interface controller : nsobject {     model *_mymodel;     uiviewcontroller *_myviewcontroller; }  -(int)actionincrease;  @end  //controller.m #import "controller.h" #import "model.h"  @implementation controller  -(id)init{     _mymodel = [[model alloc]init]; }  -(int)actionincrease {     [_mymodel increasecount];     return [_mymodel getcount];     }  @end 

version doesn't work because classes view , controller import each other , compiler gives me warning

simply: uiviewcontroller not view, it's controller

think of uiviewcontroller puppeteer , uiview puppet.

• uiviewcontroller controls displayed on uiview
• uiview's main purpose contain subviews.
• nsobject can used class, should used uiviewcontroller.

admittedly, understood better after completing codeschool's tutorial http://www.codeschool.com/courses/try-ios. highly recommend simple hands-on approach.

let's break down:

note: here utilize @property declarations instead. these save writing own setter , getter methods. (unless need override them custom functionality)

nsobject (model):

//mymodelobject.h #import <foundation/foundation.h>  @interface mymodelobject : nsobject  @property (nonatomic) int count;   @end 

uiview (view):

//myview.h #import <uikit/uikit.h>  @interface myview : uiview  // holds it's own subviews @property (strong, nonatomic) uiview *anotherview; @property (strong, nonatomic) uiimageview *myimageview;  @end 

uiviewcontroller (controller, comes here!):

//myviewcontroller.h #import <foundation/foundation.h>  #import "myview.h"  // custom view #import "mymodel.h" // custom model  @interface myviewcontroller : uiviewcontroller  @property (strong, nonatomic) myview *myview  // see how view "owned" view controller?  @end    //myviewcontroller.m  @implementation myviewcontroller   @synthesize myview;   - (void) somemethod {      [myview dosomething];   }  @end