UIActionSheet with Blocks

A very simple solution to a problem that bugged for me for sometime.

So I was recently doing some work on DNISSwiperCell when I came across the need to be able to access a custom UITableViewCell (DNISItemCell) from the event of a selection made from a UIActionSheet. Since the UIActionSheet was displayed from a button click on the cell I had access to the cell but once I left the scope of the event for the button being clicked I could not find a way to get that cell object.

I had thought of several different ways to stuff the object in various places but all the solutions really had the appearance of a hack that I knew I would hate myself for later. What I wanted was a way to pass in a callback like I do in javascript that would at the same time give me access to that object (Closure).

Luckily I had been playing with Blocks a couple of months back and I was realizing this would be a great way to solve my problem. So I first created a simple implementation of a block that I could assign to a property in the class.

It looked something like the following:

typedef void (^simpleBlock)(void);
simpleBlock callBack;

Then when I created the action sheet I could assign a block to that variable:

UIActionSheet *actionSheet = [[UIActionSheet alloc] initWithTitle:NULL delegate:self cancelButtonTitle:@"Cancel" destructiveButtonTitle:NULL otherButtonTitles:@"Action Button", nil];

callBack = ^{
    // add code here for the block

[actionSheet setActionSheetStyle:UIActionSheetStyleDefault];
[actionSheet showInView: [self view]];

Then all that remained was handling the delegate for the action sheet so that when it was dismissed it would call that block.

-(void) actionSheet:(UIActionSheet *)actionSheet willDismissWithButtonIndex:(NSInteger)buttonIndex
    if (callBack != nil) {

Done!!! Oh but wait this solution is really no different than the other hacks that I was trying to avoid plus how do I know which button on the action sheet was pressed? What about the other delegates for UIActionSheet?

So let’s take this a step further and actually find a way to handle all the delegates for UIActionSheetDelegate and at the same time handling the information that comes back with each. By inspecting the different delegates that UIActionSheetDelegate offers we can see that while there are six different delegates they can actually be grouped into two common patterns that we can with the following:

typedef void(^DNISActionSheetButtonIndex)(UIActionSheet * actionSheet, NSInteger buttonIndex);
typedef void(^DNISActionSheet)(UIActionSheet * actionSheet);

With the pattern for each delegate typedef as a block that we can use let’s proceed with bringing them into a object that we can use for identifying a property that will represent each of the delegates for UIActionSheetDelegate.

typedef void(^DNISActionSheetButtonIndex)(UIActionSheet * actionSheet, NSInteger buttonIndex);
typedef void(^DNISActionSheet)(UIActionSheet * actionSheet);

@interface DNISActionSheetBlocks : UIActionSheet

@property (strong) DNISActionSheetButtonIndex blockClickedButton;
@property (strong) DNISActionSheet blockWillPresentActionSheet;
@property (strong) DNISActionSheet blockDidPresentActionSheet;
@property (strong) DNISActionSheetButtonIndex blockDidDismissWithButton;
@property (strong) DNISActionSheetButtonIndex blockWillDismissWithButton;
@property (strong) DNISActionSheet blockActionSheetCancel;


Then move on to the implementation of the delegates and plug each of them into the properties that we have just defined. The plan is that as each delegate is called that a log message will be printed to allow me to debug the application.

@interface DNISActionSheetBlocks () 


@implementation DNISActionSheetBlocks

#pragma responding to actions
-(void) actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
    NSLog(@"blockClickedButton was called");
    if([self blockClickedButton] != nil) {
        [self blockClickedButton](actionSheet, buttonIndex);

#pragma customizing behavior
-(void) willPresentActionSheet:(UIActionSheet *)actionSheet
    NSLog(@"blockWillPresentActionSheet was called");
    if ([self blockWillPresentActionSheet] != nil) {
        [self blockWillPresentActionSheet](actionSheet);

-(void) didPresentActionSheet:(UIActionSheet *)actionSheet
    NSLog(@"blockDidPresentActionSheet was called");
    if ([self blockDidPresentActionSheet] != nil) {
        [self blockDidPresentActionSheet](actionSheet);

-(void) actionSheet:(UIActionSheet *)actionSheet willDismissWithButtonIndex:(NSInteger)buttonIndex
    NSLog(@"blockWillDismissWithButton was called");
    if ([self blockWillDismissWithButton] != nil) {
        [self blockWillDismissWithButton](actionSheet, buttonIndex);

-(void) actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex
    NSLog(@"blockDidDismissWithButton was called");
    if ([self blockDidDismissWithButton] != nil) {
        [self blockDidDismissWithButton](actionSheet, buttonIndex);

#pragma cancelling
-(void) actionSheetCancel:(UIActionSheet *)actionSheet
    NSLog(@"blockActionSheetCancel was called");
    if ([self blockActionSheetCancel] != nil) {
        [self blockActionSheetCancel](actionSheet);


I begin to use this as is when I realize that my basic implementation won’t work because the initWithTitle method requires the delegate to be passed into it. So as I begin to quickly code up an init method it dawns on me how I am going to handle the various ways buttons can be added to an actionsheet? Ok so first things let’s just create an actionsheet without any buttons:

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


-(id) initWithTitle: (NSString *) title
    self = [self initWithTitle:title delegate:self cancelButtonTitle:nil destructiveButtonTitle:nil otherButtonTitles:nil, nil];
    return self;

Yes I know that an actionsheet without any buttons doesn’t do any good but for now I can test things out. Also with a basic actionsheet created I can manually add the buttons with a call to addButtonWithTitle. With a quick test I can now see things falling into place.

Like I said creating an actionsheet without any buttons really does no good. It’s comparable to building a car but not adding any wheels to it. How do I drive this thing? So let’s add a couple of more init methods.

  • initWithTitleAndButtons – actionsheet with a title and all the buttons we want displayed.
  • initWithButtons – the title is great and all but sometimes I can do without it, just show some buttons.

Both methods are almost identical with the only exception being the title information. Because of this I am only going to talk about initWithTitleAndButtons. For a complete look at the code you can go here.


-(id) initWithTitleAndButtons:(NSString *)title cancelButtonTitle:(NSString *)cancelButtonTitle destructiveButtonTitle:(NSString *)destructiveButtonTitle otherButtonTitles:(NSString *)otherButtonTitles, ...;

The implementation is going to take some work because we will have to deal a variable number of buttons that can be supplied to it. During testing I also learned that there is an order in which you add generic buttons as well as cancel buttons and destructive buttons. So from the following implementation you can see that we first add the generic buttons followed by the cancel button and then finally add the destructive button.

-(id) initWithTitleAndButtons:(NSString *)title cancelButtonTitle:(NSString *)cancelButtonTitle destructiveButtonTitle:(NSString *)destructiveButtonTitle otherButtonTitles:(NSString *)otherButtonTitles, ...
    self = [self initWithTitle:title];
    if (self) {
        if (nil != otherButtonTitles) {
            [self addButtonWithTitle:otherButtonTitles];

            va_list arguments;
            id eachObject;

            va_start(arguments, otherButtonTitles);
            while ((eachObject = va_arg(arguments, id)))
                [self addButtonWithTitle:eachObject];
        if (nil != cancelButtonTitle) {
            NSInteger index = [self addButtonWithTitle:cancelButtonTitle];
            [self setCancelButtonIndex:index];
        if (nil != destructiveButtonTitle) {
            NSInteger index = [self addButtonWithTitle:destructiveButtonTitle];
            [self setDestructiveButtonIndex:index];
    return self;

Hopefully you will find this useful and if so check back on it because even as I wrote it and this blog I found some other areas for improvement. Might rethink the whole thing and give the developer a way to assign a block of code to an individual button?

For now you can find the source here and as always Happy Coding!!

Get in on the Ground Floor!!!

Having been a software developer for a few years I have to say that my favorite job offers or postings are those that guarantee their idea is revolutionary and as a developer I would be crazy to not want to get in on the ground floor.

Now I am not going to say that all startups are bad because clearly our industry has proven this point wrong.

What I do want to explain is that as a developer I and am I sure many others get this pitch sometimes too often. So recently when I was approached by a previous coworker looking for a developer to work on their new idea I tried to take some time to share some advice before turning down their offer.

DISCLAIMER – I know this person and while I am certain that their idea probably has some merit to it lately my time is filled with the workings of my own ideas on top of my normal work schedule and of course the schedule of a parent with a child whose day almost never seems to end of after school activities.

First and foremost you need to understand the simple fact that developers are regularly pitched the line about the next greatest idea. Don’t be discouraged if we don’t share your enthusiasm. Rather change your approach, remember that you need to sell your idea to us just like you would a potential investor or future customer.

Back when I was in college I wanted to get this part-time sales job because the hours were perfect and the commission was awesome. I learned their product (even better than the manager who interviewed me), was dressed to impress for the interview and attempted to wow with my knowledge.

At the end of the interview the manager asked me one simple question. “What is the most important skill of a salesperson?”

Stumped at first, the answer seemed simple, they had to know the product.

Wrong!!! The most important skill to a salesperson is to become their clients friend so as to build a level of trust when completing the deal. The interviewing manager sat down with me and explained as best as could be done to an 18 year old who knew everything at the time.

So first things first try to become friends with the development community and do so in a manner that doesn’t paint you as that creepy uncle who buys pizza for everyone. Take some time and learn the things we like to do and take an interest in us as much as you want us to take in your idea.

The next piece of advice should be simple and hopefully already be something you are doing.

Network, network, network.

I had recommend to my friend that they should try some of the local entrepreneurial events happening in our area.

Startup Weekend - I attended/competed in one of these events a couple of years ago and let me say that it was a blast. There is an even mix of people who are developers, marketers, sales and everyone else you can think of starting a company with. What makes these events successful is that from the very beginning a team is built which shares in the idea that the company they are building is the next greatest thing.

! Million Cups (1MC) – So while I have not attended my own local meet-up the positive feedback I hear from the community is that this is a must for new entrepreneurs. It ties back to the original idea of networking.

Hackathons – Ok so I know that some of you are probably thinking this would be a great event to meet developers and pitch your idea. While I can’t speak for all developers at these events I can share with you my personal belief. I am at the event to hangout with people who love developing software as much as I do. An unwelcome approach at an event like this will automatically land you in that creepy uncle category I mentioned earlier.

Finally, if a developer is going to dedicate their free time towards your project then you should understand that they will expect to be an equal partner in the adventure. You may have come up with the idea but we were the ones who transformed your idea into a tangible thing.

Take these recommendations and use or pursue them however you choose. I am sure that along the way more will be learned but hopefully this will get you started. I normally sign-off by saying “Happy Coding” but instead let me say this…

Happy entrepreneuring and the best of luck in making your idea a revolutionary one.

A UITextView with borders

Ok I very rarely ever work with the UITextView (more like ever) and this will be a quick post to go over what I am sure is probably a simple and widely known fix for some developers.

So in my current project I have a need for the user to be able to enter multiple lines of text as a way of storing notes:

screen shot

The screen looks simple and as such I assumed it would be easily laid out in the storyboard editor. Maybe that was my first mistake? The following picture gives you an idea of what it looks like in the storyboard and, without some code quick additions, what it also will look when run:


Are you thinking the same thing I was?  Where is the border that intuitively tells the users they can click and enter some text on the screen?

I don’t know the reason behind this (maybe someone can explain it) but apparently the UITextView does not come with borders that you can control or define with the storyboard editor. There is also no way to enter Placeholder text but I will leave that as a subject for a future post.

For now lets cover the solution of getting a border to surround the text area.

Make sure that you first include the QuartzCore.framwork and then for your view add the following include statement:

#include <QuartzCore/QuartzCore.h>

Then in your views viewDidLoad method add the following lines of code (make sure that you change the name to match):

- (void)viewDidLoad
   [super viewDidLoad];
   // Do any additional setup after loading the view.

   [[self.textViewNotes layer] setBorderColor:[[UIColor lightGrayColor] CGColor]];
   [[self.textViewNotes layer] setBorderWidth:.4];
   [[self.textViewNotes layer] setCornerRadius:8.0f];    

Run it and there you go.

I am not going to go into details about what each line of code is doing because in this situation I believe the code is doing a fairly good job at documenting itself.

Where did I get the numbers from you ask?? I hate to say this but I applied no science in those numbers and it was just guess work and trying to find something that matched the UITextField already on the screen. I tried using the getters on my title field (it’s a UITextField) but that didn’t work. Probably a subject for another post at some other time.

For now enjoy and as always Happy Coding!!