Playing with PLBlocks + UIActionSheet

ExampleUse.m

// Copied from Apple's SeismicXML code sample
// When the user taps a row in the table, display the USGS web page that displays details of the earthquake they selected.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    Earthquake *earthquake = (Earthquake *)[earthquakeList objectAtIndex:indexPath.row];

    PLActionSheet *sheet = [[PLActionSheet alloc] initWithTitle: @"Display Map"];
    
    [sheet addButtonWithTitle: @"Show USGS Site in Safari" block: ^{
        [[UIApplication sharedApplication] openURL:[NSURL URLWithString: [earthquake USGSWebLink]]];
    }];

    [sheet addButtonWithTitle: @"Show Location in Maps" block: ^{
        NSString *mapsQuery = [NSString stringWithFormat:@"z=6&t=h&ll=%f,%f", earthquake.latitude, earthquake.longitude];
        mapsQuery = [mapsQuery stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
        NSString *mapsURLString = [kMapsBaseURL stringByAppendingString:mapsQuery];
        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:mapsURLString]];
    }];

    [sheet setCancelButtonWithTitle: NSLocalizedString(@"Cancel", @"Cancel") block: ^{}];

    [sheet showInView: self.view];
    [sheet release];

    [self.tableView deselectRowAtIndexPath:indexPath animated:YES];
}

PLActionSheet.h

//
//  PLActionSheet.h
//
//  Created by Landon Fuller on 7/3/09.
//  Copyright 2009 Plausible Labs Cooperative, Inc.. All rights reserved.
//

#import <UIKit/UIKit.h>

/**
 * A simple block-enabled API wrapper on top of UIActionSheet.
 */
@interface PLActionSheet : NSObject <UIActionSheetDelegate> {
@private
    UIActionSheet *_sheet;
    NSMutableArray *_blocks;
}

- (id) initWithTitle: (NSString *) title;

- (void) setCancelButtonWithTitle: (NSString *) title block: (void (^)()) block;
- (void) addButtonWithTitle: (NSString *) title block: (void (^)()) block;

- (void) showInView: (UIView *) view;

@end

PLActionSheet.m

//
//  PLActionSheet.m
//
//  Created by Landon Fuller on 7/3/09.
//  Copyright 2009 Plausible Labs Cooperative, Inc.. All rights reserved.
//

#import "PLActionSheet.h"


@implementation PLActionSheet

- (id) initWithTitle: (NSString *) title {
    if ((self = [super init]) == nil)
        return nil;
    
    /* Initialize the sheet */
    _sheet = [[UIActionSheet alloc] initWithTitle: title delegate: self cancelButtonTitle: nil destructiveButtonTitle: nil otherButtonTitles: nil];

    /* Initialize button -> block array */
    _blocks = [[NSMutableArray alloc] init];

    return self;
}

- (void) dealloc {
    _sheet.delegate = nil;
    [_sheet release];

    [_blocks release];

    [super dealloc];
}


- (void) setCancelButtonWithTitle: (NSString *) title block: (void (^)()) block {
    [self addButtonWithTitle: title block: block];
    _sheet.cancelButtonIndex = _sheet.numberOfButtons - 1;
}

- (void) addButtonWithTitle: (NSString *) title block: (void (^)()) block {
    [_blocks addObject: [[block copy] autorelease]];
    [_sheet addButtonWithTitle: title];
}

- (void) showInView: (UIView *) view {
    [_sheet showInView: view];

    /* Ensure that the delegate (that's us) survives until the sheet is dismissed */
    [self retain];
}

- (void) actionSheet: (UIActionSheet *) actionSheet clickedButtonAtIndex: (NSInteger) buttonIndex {
    /* Run the button's block */
    if (buttonIndex >= 0 && buttonIndex < [_blocks count]) {
        void (^b)() = [_blocks objectAtIndex: buttonIndex];
        b();
    }

    /* Sheet to be dismissed, drop our self reference */
    [self release];
}

@end

addButtonWithTitle should return the index, like UIActionSheet does:

- (NSInteger) addButtonWithTitle: (NSString *) title block: (void (^)()) block {
    [_blocks addObject: [[block copy] autorelease]];
    return [_sheet addButtonWithTitle: title];
}

Then

[self addButtonWithTitle: title block: block];
_sheet.cancelButtonIndex = _sheet.numberOfButtons - 1;

should be written as

_sheet.cancelButtonIndex = [self addButtonWithTitle: title block: block];