Creating buttons in Xcode

Question

Is there a better way to do the following in Xcode for iPhone app?

I have a main navigation UIViewController screen with 4 buttons on it.

Clicking button 1 shows a sub navigation UIViewController with 4 buttons on it. Clicking button 2 shows the same sub navigation UIViewController but with 5 buttons on it. Clicking button 3 shows the same sub navigation UIViewController but with 4 buttons on it. Clicking button 4 shows the same sub navigation UIViewController but with 6 buttons on it.

To handle this I have assigned tags to each button in the main navigation. When a button is clicked, I take this tag number and pass it to sub navigation UIViewController.

Then in the sub navigation UIViewController, based on this value, I manually draw/create the sub navigation buttons as needed.

Below is how I handle this in the sub navigation UIViewController. I check to see what value was passed from main navigation UIViewController, and draw the number of buttons accordingly. I also set custom background images for each button. And for each button click I have its own selector method. Note that some buttons in the sub navigation will go to a UIViewController while some buttons will go to a TableViewController. Also each sub navigation button will have to display its own "content" in its destination view.

Is there a better, more elegant way of handling this? It just seems like a lot of code duplication to me.The example below shortened for brevity.

//  SubNavViewController.m
//  SegueTest
#import "SubNavViewController.h"
#import "GettingHereViewController.h"
#import "TableViewController.h"
#import "GettingHereContent.h"

@interface SubNavViewController ()
@end

@implementation SubNavViewController
@synthesize tagNumber;
@synthesize buttonNumber;
@synthesize buttonPushedTrackNumber;

@synthesize hotelButton;
@synthesize bAndBButton;
@synthesize caravanButton;
@synthesize selfCateringButton;
@synthesize apartmentsButton;
.
.
.
etc (19 in total)


- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
    } 
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    if (self.tagNumber == 1)
    {
        self.navigationItem.title = @"Getting Here";

        // By Air Button
        byAirButton = [UIButton buttonWithType:UIButtonTypeCustom];
        byAirButton.tag = 1;
        byAirButton.frame = CGRectMake(25, 140, 280.f, 40.f);
        UIImage *airButton = [UIImage imageNamed:@"gettingHereByAirButton.png"];
        [byAirButton setBackgroundImage:airButton forState:UIControlStateNormal];
        [self.view addSubview:byAirButton];
        [byAirButton addTarget:self action:@selector(byAirButtonClicked) forControlEvents:UIControlEventTouchUpInside];

        // By Rail Button
        byRailButton = [UIButton buttonWithType:UIButtonTypeCustom];
        byRailButton.tag = 2;
        byRailButton.frame = CGRectMake(25, 190, 280.f, 40.f);
        UIImage *railButton = [UIImage imageNamed:@"gettingHereByRailButton.png"];
        [byRailButton setBackgroundImage:railButton forState:UIControlStateNormal];
        [self.view addSubview:byRailButton];
        [byRailButton addTarget:self action:@selector(byRailButtonClicked) forControlEvents:UIControlEventTouchUpInside];

        .
        .
        . etc (2 more button)
    }
    else if (self.tagNumber == 2)
    {
        self.navigationItem.title = @"Where to Stay";

        // B&B Button
        bAndBButton = [UIButton buttonWithType:UIButtonTypeCustom];
        bAndBButton.tag = 1;
        bAndBButton.frame = CGRectMake(25, 140, 280.f, 40.f);
        UIImage *bedAndBreakfast = [UIImage imageNamed:@"whereToStayBedAndBreakfastButton.png"];
        [bAndBButton setBackgroundImage:bedAndBreakfast forState:UIControlStateNormal];
        [self.view addSubview:bAndBButton];
        [bAndBButton addTarget:self action:@selector(bAndBButtonClicked) forControlEvents:UIControlEventTouchUpInside];
        .
        .
        . etc (do this for the rest of the buttons)  
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

- (void) byAirButtonClicked
{
    GettingHereContent *gettingHere = [GettingHereContent new];
    gettingHere = @"By Air";
    NSLog(@"Content: %@", gettingHere);
    [self performSegueWithIdentifier:@"gettingHereSegue" sender:self];
}

- (void) bAndBButtonClicked
{
    GettingHereContent *gettingHere = [GettingHereContent new];
    gettingHere = @"Bed and Breakfast";
    NSLog(@"Content: %@", gettingHere);
    [self performSegueWithIdentifier:@"tableViewSegue" sender:self];
}

.
.
. (do this for all buttons - 19 in total)

- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
}
@end

Answer 1

First I would recommend to create a NS_ENUM defining all your buttons in the following way:

typedef NS_ENUM(NSUInteger, ButtonTag)
{
    ButtonTagHotel,
    ButtonTagOther,
    ...
}

Then in viewDidLoad: you could create an Array with all buttons, that are needed for your current state like the following way:

NSMutableArray *buttonTags = [[NSMutableArray alloc] init];

if (self.tagNumber == 1 || self.tagNumber == 3)
    [buttonTags addObject: @(ButtonTagHotel)];

if (self.tagNumber == 5 || self.tagNumber == 8)
    [buttonTags addObject: @(ButtonTagOther)];

// etc...

When you have build up your needed button tags, you can create and add them all in one loop:

uint cnt = 0;

for (NSNumber *tag in buttonTags)
{
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
    btn.tag = [tag unsignedIntValue];
    btn.frame = CGRectMake(25, 20 + (cnt * 50.f), 280.f, 40.f);
    UIImage *image = [UIImage imageNamed:@"genericButtonImage.png"];
    [btn setBackgroundImage:image forState:UIControlStateNormal];
    [self.view addSubview:btn];
    [btn addTarget:self action:@selector(buttonTouched:) forControlEvents:UIControlEventTouchUpInside];

    cnt++;
}

If you have to set a different image for every button, then you should create another array that is holding all image names indexed by the ButtonTag enum...

Now you just have to implement -(void)buttonTouched:(UIButton*)sender:

-(void)buttonTouched:(UIButton*)sender
{
    switch (sender.tag) {
        case ButtonTagHotel:
        {
            // do your stuff
        }
            break;
        ...
        default:
            break;
    }
}