How to get indexes from NSIndexset into an NSArray in cocoa?

Question

I\'m getting the select items from a table view with:

NSIndexSet *selectedItems = [aTableView selectedRowIndexes];

what\'s the best way to

Answer 1

I did it by creating a category on NSIndexSet. This kept it small and efficient, requiring very little code on my part.

My interface (NSIndexSet_Arrays.h):

/**
 *  Provides a category of NSIndexSet that allows the conversion to and from an NSDictionary
 *  object.
 */
@interface NSIndexSet (Arrays)

/**
 *  Returns an NSArray containing the contents of the NSIndexSet in a format that can be persisted.
 */
- (NSArray*) arrayRepresentation;

/**
 *  Initialises self with the indexes found wtihin the specified array that has previously been
 *  created by the method @see arrayRepresentation.
 */
+ (NSIndexSet*) indexSetWithArrayRepresentation:(NSArray*)array;

@end

and the implementation (NSIndexSet_Arrays.m):

#import "NSIndexSet_Arrays.h"

@implementation NSIndexSet (Arrays)

/**
 *  Returns an NSArray containing the contents of the NSIndexSet in a format that can be persisted.
 */
- (NSArray*) arrayRepresentation {
    NSMutableArray *result = [NSMutableArray array];

    [self enumerateRangesUsingBlock:^(NSRange range, BOOL *stop) {
        [result addObject:NSStringFromRange(range)];
    }];

    return [NSArray arrayWithArray:result];
}

/**
 *  Initialises self with the indexes found wtihin the specified array that has previously been
 *  created by the method @see arrayRepresentation.
 */
+ (NSIndexSet*) indexSetWithArrayRepresentation:(NSArray*)array {
    NSMutableIndexSet *result = [NSMutableIndexSet indexSet];

    for (NSString *range in array) {
        [result addIndexesInRange:NSRangeFromString(range)];
    }

    return result;
}


@end