add GLKViewController to subview - GLKView context causes crash - objective-c

Question

I have a pretty simple set up in mind, having a mainViewController that has a GLKViewController on top of it. The idea is having my GLKViewController in a box, that take sup 1/3 of the screen, on the mainViewController. This can be seen below:
That white box is my own custom GLKViewController with the follow code:
boxViewController.h
//boxViewController.h
#import <UIKit/UIKit.h>
#import <GLKit/GLKit.h>
#interface boxViewController : GLKViewController
#end
boxViewController.m
//boxViewController.m
#import "boxViewController.m"
#interface boxViewController () { }
#property (strong, nonatomic) EAGLContext *context;
#end
#implementation boxViewController
-(void)viewDidLoad {
[super viewDidLoad];
self.context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
if (!self.context) {
NSLog(#"Failed to create ES context");
}
GLKView *view = (GLKView *)self.view;
// view.context = self.context;
view.drawableDepthFormat = GLKViewDrawableDepthFormat24;
}
#end
On my mainViewController in the viewDidLoad I simply call boxViewController like this:
boxViewController* box = [[boxChartViewController alloc] init];
box.view.layer.frame = CGRectMake(10, 50, self.view.frame.size.width-20, self.view.frame.size.height/3);
[self.view addSubview:box.view];
which works perfect.
Notice that in my boxViewController.m I had view.context = self.context commented out. If you uncomment it, my application crashes without any error messaging (it breaks with a EXC_BAD_ACCESS in the objc_msgSend assembly code [line 8 to be specific]).
What am I doing incorrectly that when I set the context the application crashes? From all the tutorials I noticed that they have the same set up, except not setting the controller on another controller. Though I don't understand why GLKViewController couldn't be framed on another controller, so I don't think that's the issue.

Answer 1

After a few hours of messing around I found that adding the viewController as a child works:
#import "mainViewController.h"
#implementation mainViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.view.layer.backgroundColor = [UIColor colorWithRed:242.0f/255.0f green:242.0f/255.0f blue:242.0f/255.0f alpha:1.0].CGColor;
boxViewController* chart = [[boxViewController alloc] init];
chart.view.layer.frame = CGRectMake(10, 50, self.view.frame.size.width-20, self.view.frame.size.height/3);
chart.view.layer.borderColor = [UIColor blackColor].CGColor;
chart.view.layer.borderWidth = 2.0f;
[self addChildViewController:chart];
[self.view addSubview:chart.view];
}