Blog Reader Challenge

Question

Extra Credit Table View Sections

Create sections in your table view to categorize blog posts into Design, Development and Mobile.

Hint: You can create three separate arrays and modify the method numberOfSectionsInTableView to return the number three. In your cellForRowAtIndexPath method check indexPath.section and write an if statement or a switch statement to return text from the appropriate array.

I've created three separate properties for the sections in the header file:

@property (nonatomic, strong) NSArray *mobile;
@property (nonatomic, strong) NSArray *development;
@property (nonatomic, strong) NSArray *design;

I`ve also initialised these arrays in the implementation file:

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.mobile = [NSArray
                   arrayWithObjects:@"The Missing Widget in the Android SDK: SmartImageView",
                                    @"Get Started with iOS Development", nil];
    self.design = [NSArray
                   arrayWithObjects:@"An Interview with Shay Howe",
                                    @"Getting a Job in Web Design and Development", nil];
    self.development = [NSArray
                        arrayWithObjects:@"Treehouse Friends: Paul Irish",
                                    @"Treehouse Show Episode 13 -  Navicons and Framework Flights", nil];
}

And modified the numberOfSectionsInTableView method to return the number 3.

I managed to do this as well:

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // Return the number of rows in the section.
    if (section == 0) {
        return [self.mobile count];
    } else if (section == 1) {
        return [self.design count];
    } else if (section == 2) {
        return [self.development count];
    }

    return 0;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

    if (indexPath.section == 0) {
           cell.textLabel.text = [self.mobile objectAtIndex:indexPath.row];
    } else if (indexPath.section == 1) {
           cell.textLabel.text = [self.design objectAtIndex:indexPath.row];
    } else if (indexPath.section == 2) {
           cell.textLabel.text = [self.development objectAtIndex:indexPath.row];
    }

    return cell;
}

Does anyone see what's wrong? When I run I see a screen with all of the rows and labels, but no sections...

Answer 1 · 2014-07-16T11:25:37Z

July 16, 2014 11:25am

Hi Rodrigo,

I too battled with this one for a couple of days before I finally got it to work. I had to add another section (maybe there's another way, but I couldn't find it):

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{

    NSString *title = nil;
    if (section == 0) {
        title=@"Mobile";
    } else if (section == 1) {
        title=@"Design";
    } else if (section == 2) {
        title=@"Development";
    }
    return title;
}

Hopefully this helps you.

Answer 2 · 2014-07-12T12:56:30Z

July 12, 2014 12:56pm

Hi Rodrigo,

You will also need to implement a similar if-else statement into numberOfRowsInSection:.

Base on the section index you need to return the number of rows for that section, which is actually the number of items in your arrays.

- (NSInteger)numberOfRowsInSection:(NSInteger)section {
    if (section == 0) {
           return [mobile count];
    } else if (section == 1) {
           return [design count];
    } else if (section == 2) {
           return [development count];
    }
    return 0;
}

Answer 3 · 2014-09-15T09:42:49Z

September 15, 2014 9:42am

//  TableViewController.m
//  BlogReader
//
//  Created by Amit Bijlani on 12/6/12.
//  Copyright (c) 2012 Amit Bijlani. All rights reserved.
//

#import "TableViewController.h"

@interface TableViewController ()

@end

@implementation TableViewController

- (id)initWithStyle:(UITableViewStyle)style
{
    self = [super initWithStyle:style];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.mobile = [NSArray arrayWithObjects:@"The Missing Widget in the Android SDK: SmartImageView",
                   @"Get started with iOS Development",
                   nil];
    self.design = [NSArray arrayWithObjects:
                   @"An Interview with Shay Howe",
                   @"Treehouse Friends: Paul Irish",
                   nil];
    self.development = [NSArray arrayWithObjects:
                   @"Getting A Job In Web Design and Development",
                   @"Treehouse Show Episode 13 &#8211; LLJS, Navicons and Framework Flights",
                   nil];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    // Return the number of sections.
    return 3;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // Return the number of rows in the section.
    if (section == 0) {
        return [self.mobile count];
    } else if (section == 1) {
        return [self.design count];
    } else if (section == 2) {
        return [self.development count];
    }
    return 0;

}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
    if (indexPath.section == 0) {
        cell.textLabel.text = [self.mobile objectAtIndex:indexPath.row];
    } else if (indexPath.section == 1) {
        cell.textLabel.text = [self.design objectAtIndex:indexPath.row];
    } else if (indexPath.section == 2) {
        cell.textLabel.text = [self.development objectAtIndex:indexPath.row];
    }
    return cell;
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
    NSString *title = nil;
    if (section == 0) {
        title = @"Mobile";
    } else if (section == 1) {
        title = @"Design";
    } else if (section == 2) {
        title = @"Development";
    }
    return title;
} 

/*
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the specified item to be editable.
    return YES;
}
*/

/*
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        // Delete the row from the data source
        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
    }   
    else if (editingStyle == UITableViewCellEditingStyleInsert) {
        // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
    }   
}
*/

/*
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
}
*/

/*
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the item to be re-orderable.
    return YES;
}
*/

#pragma mark - Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Navigation logic may go here. Create and push another view controller.
    /*
     <#DetailViewController#> *detailViewController = [[<#DetailViewController#> alloc] initWithNibName:@"<#Nib name#>" bundle:nil];
     // ...
     // Pass the selected object to the new view controller.
     [self.navigationController pushViewController:detailViewController animated:YES];
     */
}

@end

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Rodrigo Chousal

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Blog Reader Challenge

Rodrigo Chousal

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3 Answers

Martin Granger

Martin Granger

Robert Bojor

Robert Bojor

Rodrigo Chousal

Rodrigo Chousal

Will Macleod

Will Macleod