OO approach to view controller classes in obj-c - objective-c

Question

I have 10 different pages built into a slider control in my app, these pages are setup using storyboards.
The only difference on each page is a different web view to display rich text and a different image as a background are used.
Is it possible for me to have one view controller for all 10 pages and setup some flags in the constructor which would be executed on every page when its loaded to tell it what image and web view to show? If so what would this look like?
Thanks,
Lewis.

Answer 1

You can create subclass of UIViewController, for example MyViewController.
And then replace your .h file with:
#import <UIKit/UIKit.h>
#interface MyViewController : UIViewController
#property (nonatomic, strong) UIWebView *myWebView;
#property (nonatomic, strong) UIImageView *myImageView;
- (id)initWithURLString:(NSString *)urlString image:(NSString *)imageName;
#end
And your .m file with:
#import "MyViewController.h"
#interface MyViewController ()
#end
#implementation MyViewController
#synthesize myWebView = _myWebView;
#synthesize myImageView = _myImageView;
- (id)initWithURLString:(NSString *)urlString image:(NSString *)imageName
{
self = [super init];
if (self) {
NSURL *url = [NSURL URLWithString:urlString];
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];
_myWebView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 320, 400)];
[_myWebView loadRequest:urlRequest];
_myImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];
_myImageView.frame = CGRectMake(0, 400, 60, 60);
}
return self;
}
#end
And then just create an instances of your UIViewController subclass:
MyViewController *vCon = [[MyViewController alloc] initWithURLString:someURLString image:imageName];

Answer 2

I think the best approach would be to define a data source for your view controller. This data source would have the following interface, e.g.:
#protocol MyVCDataSource
- (NSUInteger)numberOfPages;
- (NSString*)htmlContentForPageIndex:(NSUInteger)index;
- (NSString*)backgroundForPageIndex:(NSUInteger)index;
#end
You would provide your view controller with a member called datasource that would be initialized in the initWithDatasource method:
#interface MyVC : UIViewController
...
#property (nonatomic, weak) id<MyVCDataSource> datasource;
- (id)initWithDatasource:(id<MyVCDataSource>)ds;
Then your view controller would just ask the data source for the HTML data or the background file name when it needs it:
- (void)viewDidLoad {
self.view.backgroundColor = GET_BACKGROUND_FROM_STRING([self.datasource backgroundForPageIndex:self.currentIndex]);
[self.webView loadHTMLString: [self.datasource htmlContentForPageIndex:self.currentIndex]];
....
}
I assumed that the protocol just returns strings, but indeed you can have it return what you need (e.g., an image, a color, an URL), it all depends on the internals of your class.
Finally, your datasource object could be any object (even your MyVC instance) and return its data by indexing into an array:
- (NSString*)htmlContentForPageIndex:(NSUInteger)index {
return [self.htmlPages objectAtIndex:index];
}
etc.