A template for a custom UIViewController with proper model handling. See http://www.ios-coding.com/blog/2014/06/22/model-handling-in-uiviewcontroller/

MyViewController-ModelHandling.m

//    Copyright 2014 bitecode, Michael Ochs
//
//    See http://www.ios-coding.com/blog/2014/06/22/model-handling-in-uiviewcontroller/
//
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.


// MyViewController.h:
@interface MOCDefaultViewController : UIViewController

@property (nonatomic, strong, readwrite) MyModel *myModel;

@end



// MyViewController.m:
@implementation MOCDefaultViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
	
    [self setupSubviewHierarchy];
    [self updateViewWithCurrentModel];
}

- (void)setupSubviewHierarchy
{
    // if not using Interface Builder, setup your view hierarchy here
    // do not use your model in here!
}

- (void)updateViewWithCurrentModel
{
    MyModel *myModel = self.myModel;
    // set text labels, text inputs, switches and other UI components
    // according to your model's state in here.
}

- (void)setMyModel:(MyModel *)myModel
{
    _myModel = myModel;
    if (self.isViewLoaded) {
        [self updateViewWithCurrentModel];
    }
}

@end