Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
Generic UIAlertViewDelegate implementation that translates into a convenient block-based API. Go to http://cutecoder.org to read how to use this.
//
// BSAlertViewDelegateBlock.h
// SpeechTimer2
//
// Created by Sasmito Adibowo on 25-12-13.
// Copyright (c) 2013-2014 Basil Salad Software. All rights reserved.
//
// Licensed under the BSD License <http://www.opensource.org/licenses/bsd-license>
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
// OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
// SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
#import <UIKit/UIKit.h>
/**
Adapts UIAlertViewDelegate protocol into a block-friendly interface.
*/
@interface BSAlertViewDelegateBlock : NSObject<UIAlertViewDelegate>
/**
Designated initializer.
*/
-(id) initWithAlertView:(UIAlertView*) alertView;
@property (nonatomic,strong) void(^clickedButtonAtIndexBlock)(UIAlertView* alertView,NSInteger buttonIndex);
@property (nonatomic,strong) void(^alertViewCancelBlock)(UIAlertView* alertView);
@property (nonatomic,strong) void(^willPresentAlertViewBlock)(UIAlertView* alertView);
@property (nonatomic,strong) void(^didPresentAlertViewBlock)(UIAlertView* alertView);
@property (nonatomic,strong) void(^willDismissWithButtonIndexBlock)(UIAlertView* alertView,NSInteger buttonIndex);
@property (nonatomic,strong) void(^didDismissWithButtonIndexBlock)(UIAlertView* alertView,NSInteger buttonIndex);
@property (nonatomic,strong) BOOL(^alertViewShouldEnableFirstOtherButtonBlock)(UIAlertView* alertView);
@end
//
// BSAlertViewDelegateBlock.m
// SpeechTimer2
//
// Created by Sasmito Adibowo on 25-12-13.
// Copyright (c) 2013-2014 Basil Salad Software. All rights reserved.
// http://basilsalad.com
//
// Licensed under the BSD License <http://www.opensource.org/licenses/bsd-license>
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
// OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
// SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
#import <objc/runtime.h>
#import "BSAlertViewDelegateBlock.h"
const char* const BSAlertViewDelegateBlockKey = "BSAlertViewDelegateBlockKey";
@interface BSAlertViewDelegateBlock ()
@property (nonatomic,weak) UIAlertView* alertView;
@end
@implementation BSAlertViewDelegateBlock
-(void) alertViewDelegateBlock_cleanup
{
UIAlertView* alertView = self.alertView;
// remove all handler blocks in case one of these blocks inadvertendly caused a circular reference to this delegate object.
self.clickedButtonAtIndexBlock = nil;
self.alertViewCancelBlock = nil;
self.willPresentAlertViewBlock = nil;
self.didPresentAlertViewBlock = nil;
self.willDismissWithButtonIndexBlock = nil;
self.didDismissWithButtonIndexBlock = nil;
self.alertViewShouldEnableFirstOtherButtonBlock = nil;
// finally remove this delegate from the alert view
if (alertView.delegate == self) {
alertView.delegate = nil;
objc_setAssociatedObject(alertView, BSAlertViewDelegateBlockKey, nil, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
}
-(id) initWithAlertView:(UIAlertView *)alertView
{
if (self = [super init]) {
self.alertView = alertView;
objc_setAssociatedObject(alertView, BSAlertViewDelegateBlockKey, self, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
alertView.delegate = self;
}
return self;
}
#pragma mark UIAlertViewDelegate
// Called when a button is clicked. The view will be automatically dismissed after this call returns
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
void(^clickedButtonAtIndexBlock)(UIAlertView* alertView,NSInteger buttonIndex) = self.clickedButtonAtIndexBlock;
if (clickedButtonAtIndexBlock) {
clickedButtonAtIndexBlock(alertView,buttonIndex);
}
}
// Called when we cancel a view (eg. the user clicks the Home button). This is not called when the user clicks the cancel button.
// If not defined in the delegate, we simulate a click in the cancel button
- (void)alertViewCancel:(UIAlertView *)alertView
{
void(^alertViewCancelBlock)(UIAlertView* alertView) = self.alertViewCancelBlock;
if (alertViewCancelBlock) {
alertViewCancelBlock(alertView);
}
[self alertViewDelegateBlock_cleanup];
}
- (void)willPresentAlertView:(UIAlertView *)alertView
{
void(^willPresentAlertViewBlock)(UIAlertView* alertView) = self.willPresentAlertViewBlock;
if (willPresentAlertViewBlock) {
willPresentAlertViewBlock(alertView);
}
}
- (void)didPresentAlertView:(UIAlertView *)alertView
{
void(^didPresentAlertViewBlock)(UIAlertView* alertView) = self.didPresentAlertViewBlock;
if (didPresentAlertViewBlock) {
didPresentAlertViewBlock(alertView);
}
}
- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex
{
void(^willDismissWithButtonIndexBlock)(UIAlertView* alertView,NSInteger buttonIndex) = self.willDismissWithButtonIndexBlock;
if (willDismissWithButtonIndexBlock) {
willDismissWithButtonIndexBlock(alertView,buttonIndex);
}
}
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
void(^didDismissWithButtonIndexBlock)(UIAlertView* alertView,NSInteger buttonIndex) = self.didDismissWithButtonIndexBlock;
if (didDismissWithButtonIndexBlock) {
didDismissWithButtonIndexBlock(alertView,buttonIndex);
}
[self alertViewDelegateBlock_cleanup];
}
- (BOOL)alertViewShouldEnableFirstOtherButton:(UIAlertView *)alertView
{
BOOL(^alertViewShouldEnableFirstOtherButtonBlock)(UIAlertView* alertView) = self.alertViewShouldEnableFirstOtherButtonBlock;
if (alertViewShouldEnableFirstOtherButtonBlock) {
return alertViewShouldEnableFirstOtherButtonBlock(alertView);
}
// default to enable.
return YES;
}
@end
@krin-san

This comment has been minimized.

Copy link

krin-san commented Nov 13, 2014

Let's refer directly to the article: http://cutecoder.org/programming/painless-alert-view/

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.