Nesting GLKView into UIViewController
I'm trying to use GLKView in UIViewController, my code looks like this

CustomViewController.h

    #import <UIKit/UIKit.h>
    #import <GLKit/GLKit.h>
    
    @interface CustomViewController : UIViewController
    {
    	NSString * name;
    }
    
    @property NSString * name;

CustomViewController.m

    #import "CustomViewController.h"
    
    @interface CustomViewController ()
    
    @end
    
    @implementation CustomViewController
    @synthesize name;
    
    - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
    {
        self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
        if (self) {
            // Custom initialization
        }
        return self;
    }
    
    - (void)viewDidLoad
    {
        [super viewDidLoad];
    	// Do any additional setup after loading the view.
    	EAGLContext * context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
    	CGRect mainScreen = [[UIScreen mainScreen] bounds];
    	GLKView * viewGL = [[GLKView alloc] initWithFrame:CGRectMake(mainScreen.size.width / 2, mainScreen.size.height / 2, 50, 50)];
    	viewGL.context = context;
    	[self.view addSubview:viewGL];
    }
    
    - (void)viewDidUnload
    {
        [super viewDidUnload];
        // Release any retained subviews of the main view.
    }
    
    - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
    {
        return (interfaceOrientation == UIInterfaceOrientationPortrait);
    }
    
    @end

How can I define the draw/render method of GLKView? and where can I init OpenGL? Any suggestions?
Nesting GLKView into UIViewController
===

I'm trying to use GLKView in UIViewController, my code looks like this

CustomViewController.h

    #import <UIKit/UIKit.h>
    #import <GLKit/GLKit.h>
    
    @interface CustomViewController : UIViewController
    {
    	NSString * name;
    }
    
    @property NSString * name;

CustomViewController.m

    #import "CustomViewController.h"
    
    @interface CustomViewController ()
    
    @end
    
    @implementation CustomViewController
    @synthesize name;
    
    - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
    {
        self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
        if (self) {
            // Custom initialization
        }
        return self;
    }
    
    - (void)viewDidLoad
    {
        [super viewDidLoad];
    	// Do any additional setup after loading the view.
    	EAGLContext * context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
    	CGRect mainScreen = [[UIScreen mainScreen] bounds];
    	GLKView * viewGL = [[GLKView alloc] initWithFrame:CGRectMake(mainScreen.size.width / 2, mainScreen.size.height / 2, 50, 50)];
    	viewGL.context = context;
    	[self.view addSubview:viewGL];
    }
    
    - (void)viewDidUnload
    {
        [super viewDidUnload];
        // Release any retained subviews of the main view.
    }
    
    - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
    {
        return (interfaceOrientation == UIInterfaceOrientationPortrait);
    }
    
    @end

How can I define the draw/render method of GLKView? and where can I init OpenGL? Any suggestions?