Autogroup UITableView alphabetically

Question

Is there a way to auto group/auto-section my UITableView alphabetically? I have a huge array which is being displayed nicely, but it would be even better if I h

Answer 1

I have a pod just for this:

https://github.com/chrisladd/CGLAlphabetizer/

pod 'CGLAlphabetizer', '~> 0.1'

It creates a dictionary of arrays keyed by letters of the alphabet from a single array of objects and an arbitrary keyPath.

alphabetizedDictionary = [CGLAlphabetizer alphabetizedDictionaryFromObjects:anArray usingKeyPath:@"keyPath"];

So, assuming you had the model object that looked like this:

@interface CGLContact : NSObject
@property (nonatomic) NSString *firstName;
@property (nonatomic) NSString *lastName;

@property (nonatomic, readonly) NSString *fullName;

@end

Your tableViewController implementation might look something like this:

static NSString * const CGLContactsCellIdentifier = @"CGLContactsCellIdentifier";

@interface CGLContactsTableViewController ()
@property (nonatomic) NSDictionary *alphabetizedDictionary;
@property (nonatomic) NSArray *sectionIndexTitles;
@end

@implementation CGLContactsTableViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:CGLContactsCellIdentifier];
}

- (void)setContacts:(NSArray *)contacts {
    _contacts = contacts;
    self.alphabetizedDictionary = [CGLAlphabetizer alphabetizedDictionaryFromObjects:_contacts usingKeyPath:@"lastName"];
    self.sectionIndexTitles = [CGLAlphabetizer indexTitlesFromAlphabetizedDictionary:self.alphabetizedDictionary];

    [self.tableView reloadData];
}

- (CGLContact *)objectAtIndexPath:(NSIndexPath *)indexPath {
    NSString *sectionIndexTitle = self.sectionIndexTitles[indexPath.section];
    return self.alphabetizedDictionary[sectionIndexTitle][indexPath.row];
}

#pragma mark - Table view data source

- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView {
    return self.sectionIndexTitles;
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return [self.sectionIndexTitles count];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    NSString *sectionIndexTitle = self.sectionIndexTitles[section];
    return [self.alphabetizedDictionary[sectionIndexTitle] count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CGLContactsCellIdentifier forIndexPath:indexPath];

    CGLContact *contact = [self objectAtIndexPath:indexPath];
    cell.textLabel.text = contact.fullName;

    return cell;
}

@end

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