Ordered Results using DirectoryIterator

No matter if you are beginner or expert one of the most command tasks that you  will do is writing some class/script/snippet of directory iteration.

"Get a list of files/directories and display"

With PHP there are about baker's dozen different ways of accomplishing this.  In the beginning there was functional verbose way:

It gets the job done, but not very extensive and it seems VERY verbose.  Being that my development background started with OOP I was never a fan.  Fastforward a little bit and PHP introduced "dir", which returns an instance of the Directory class.

Not to bad, but still verbose and God forbid that you have to do recursion.

With PHP5 came the SPL. Standard PHP Library, which still to this day I don't know why it isn't prompted more. Pure object-oriented and has the flexibility to accomplish the basic tasks set before them, as well as, the strength to be a customizable as the developer wants.

The class which most use for directory iteration is…hold your breathe: DirectoryIterator.  In my use case I need to server up image path and meta information in an HTTP request so that an iPhone app could parse the response and grab the appropriate images for display.

Basic usage:

See how easy that was.  OOP at it's best except for one little thing.  The images were not coming back in the correct order.  They are named on the filesystem: "00.png", "01.png", "02.png", etc., but the return was random.  While I can appreciate DirectoryIterator being a more "abstract" enumator and not really having a "natural" sort order I still was frustrated.  Remember, what I said earlier though about the SPL being customizable and OO.  You can subclass the DirectoryIterator and supply your own comparator, which by design, is best practice for a large system.  I, however, was looking  for the shortest line between two points and creating a subclass seemed overkill.

*I really wish PHP had categories like Objective-C or method swizzling

Not a problem though.  I can just pass a callback function to the usort function and call it a day.  H.O.P.  This logic does work, but the array that I wanted to sort is associative so the key that should be sorted is "name". The callback function for usort ONLY accepts two arguments which it compares.  I had to bake in the key which isn't flexible.  I would rather reuse the functionality by being able to pass in the key to sort on. PHP isn't the only language that has this result.  If you look at the behavior of an NS(Mutable)Dictionary in objective-c which makes copies of keys, so the objects in the key array will be different. Objective-C offers the ability to pass in a comparator when iterating over the dictionary so that the sort order is defined by the developer not by the hash.

In a perfect world I would be able to do the following:

Here is the example script for my use case. (changed some path names for security reasons)

Custom UIActionSheet Using Core Animation

About four months I posted a blog and project that showed how to customize the buttons of a UIActionSheet.  In the disclaimer I stated that because of the use of the private api's if you attempted to submit your app with this technique to the App Store it will get rejected.

This time around a created a simple, yet effective customized, mock UIActionSheet.  Essentially it is just a custom UIView with three buttons that animates and dismisses just let an UIActionSheet.  All you have to do is assign a method to each of the buttons.

If I have time then I'll try and make it even more extensible by creating a custom delegate to make the classes even more reusable.

Upcoming to Universal iOS App on GitHub

In anticipation for the upcoming public release of iOS 4.2, I have updated my Universal iOS App project (iAd Branch).  The project will run on 3.2 and up with iAd support for iPhone and iPad (4.2 only for iPad).

I ran into some interesting hurdles while working on this update.  The first of which is that adding in iAd support for a project using a UISplitViewController SUCKS! #FAIL When iAds where first offered in the 4.0 iOS they came in two different size: 320 x 50 (ADBannerContentSizeIdentifier320x50) and 480 x 32 (ADBannerContentSizeIdentifier480x32) which served their purpose since you could use iAds only on the phone.  When iAd support was added for the iPad Apple was smart and deprecated those properties and added ADBannerContentSizeIdentifierPortrait and ADBannerContentSizeIdentifierLandscape, thus abstracting the dimensions that are available for any current and future devices.  This unification works great on the iPhone and iPad...except for when you implement UISplitViewController on the iPad.  The reason being that even though your root view or "detail" view controller are in landscape or portrait mode their widths aren't in the expected frame width for either choose of iAd. Thus you get an inaccurate display and you will an error in:

- (void)bannerView:(ADBannerView *)banner didFailToReceiveAdWithError:(NSError *)error

stating that an ad has displayed but is being obscured. In order to get around this I had to add in some padding to readjust the 'y' coordinate for the tableview's frame (only when the ad appears).  Why the rotation, and only on the iPad, gets screwed up I am not sure at the moment.  I created a simple, iPad only project and got the same results so there might be a bug, but until I am able to verify, my "padding" works".

It is important that if you clone/run this project that you read the debug console for iad display errors.  These are relevant errors passed to the delegate method and don't have to do with my code.  You will notice in the video that ad fails to load the first round.  This is due to an error from Apple serving up the ad because inventory is not available. Second time is the charm.

*important - always implement delegates to handle failures

In the next few weeks I'll be adding a branch where the Universal app will have Tabbar support.

CWCustomAccessoryView - Custom UITableViewCell AccessoryView

Around the same time that Oliver Drobnik (Formely Dr. Touch) published his blog entry, Custom-Colored Disclosure Indicators, I was also in the middle a client's project where the table view cells each had a different colored uitablviewcellaccessory.  I had to deal with 20 different images for the accessory views (10 for pre-iPhone4 and 10 for retina display).   At the time I knew having to manage the images themselves and the code to display those views was unwieldy and cumbersome.  I took inspiration from Oliver's post to come up with a class, CWCustomAccessoryView, which allows the developer to customize the way the accessoryView for a cell looks which includes the stroke, _>_, and fill color.

Though the code is almost a month old and I haven't had that much time on improving it, but after reading Ray Wenderlich's blog on Arc's and Paths I see I need to make the accessory view look for like Apple's detail disclosure button to make everything look really polished.

Per usual the code is hosted over at GitHub.  Comments and improvements are ALWAYS welcomed.

Customizing UIActionSheet Buttons

One of the great benefits of iOS development is that Apple has provided the ability to customize almost any element thus not limiting a designer or developer with a stock look and feel.  Just take a look at subtle examples in Twitter for iPhone to the extreme of the Outside Weather app or Starbucks.  I am working on a nice size project and one of the requirements is to have the UIActionSheet buttons be a different color than the default gray color.  This turned out the be as straightforward as trying to change the look and feel of a tabbar.

::NOTE TO APPLE:: Customizing Tabbars and UIActionSheet buttons should be a lot easier. ::END NOTE::

It took a few hours, but I finally knocked it out.  At first glance I figured that each one of the buttons would be an instance of UIButton and I could located them in the view hierarchy and just update the background color either in a delegate method or subclass UIActionSheet and override drawRect:.  NEGATIVE.  

My next possible approach was to create my own custom view(s) and slap them on the UIActionSheet's main view and send everything else to the back.  Granted that has worked for some people and is a totally viable option, but I found it to be a very hacky solution for what I was doing.

After looking up a few questions on StackOverflow it turns out that sometime after iOS 3.1 the subviews in the UIActionSheet are an undocumented class instances of UIThreePartButton.


After digging up that little nugget about UIThreePartButton I finally had turned a corner.  The next hurdle was trying to find the correct method to use from the UIThreePartButton class to change the background color.  Unfortunately, there isn't a backgroundColor property for that.  Granted since I am dealing with a class that inherits form UIView I could set the subviews backgroundColor property to [UIColor redColor], but when I did that I didn't get the expected result of a button with a red background.  The button became a red tint and the view behind the button was red as well.  Obstacle.  Looking at the methods/properties that I DID have I went on a little intuition that Apple wasn't using a color, but a stretchable background image for the button.  I grabbed the background graphic that I wanted and used - (void) setBackgroundImage:.  SUCCESS!!!!!!!

I wasn't quite finished.  Background button was what I wanted, but I needed to change the font color from black to white.  But wait there isn't a method to set the font. However, UIPushButton inherits from UIThreePartButton so once again going on an educated guess/intution I was able to use setTitleColor:forState: and perfection.  Excatly what I wanted and needed.  UIActionSheet with red buttons and white font.

Even though I can't submit any app to the AppStore because of the undocumented class working through the exercise was very enlightening in the areas of ui customization, design patterns and general problem solving skills which should always be in the top of a developer's skillset.

I posted my example on github.  It was compiled with 4.0 with XCode 4 Preview 3, but XCode 3.x should work.  If you run into any problems then let me know.

Creating a Universal iOS App Tutorial

Just when I thought I had a somewhat decent grasp on developing and deploying iOS apps Apple came out with the iPad and threw a whole new element in the mix when it comes to developing.  Thankfully, the iPad will allow iPhone apps to run on the device, but the user experience is definitely sub-par.  So what is the best approach to providing an native iPhone app and a native iPad app?  The first option is to duplicate your existing iPhone app code base and modify all your views and some of the controllers to take advantage of the features in the 3.2 SDK.  The problem with that is the massive DUPLICATION of code and to be honest it seems quite lazy.  I have seen lots of examples where developers use the idiom check for which device is being used, as well as, runtime checks for selectors in order to leverage the correct methods/classes for the given device.  While this is certainly a better approach then having two separate code bases with 90% of the same code you now have code that is sprinkled/littered with if/else checks.  Unfortunately, you are once again stuck with code that will be maintainable for long.  After reading the chapter on universal apps from the upcoming book from Pragmatic Programmers, iPad Programming, I found a much better design pattern of splitting out the app into Shared, iPhone and iPad resources, classes and delegates.

As a side note, due to the ever exponential growth of iOS device popularity developers are not going to have the bonus of just jumping straight into writing an app like we did when there was just the iPhone.  A lot more thought needs to be given to design patterns (especially regards to the quality of your MVC) and application flow.

In order to make life a little easier on myself since a few universal apps are coming in my near future I decided to create a basic "template" for a universal app.

  • Compiled for 3.2 and 4.0
  • Utilizes navigation controller based app for iPhone device and SplitViewController for iPad
  • Shared "model" class and controller classes
  • Separate resources (classes/xibs) for the different devices

Comments and improvements are ALWAYS welcome.  One improvement that I know I want to make is having the "detail" controller from the SplitViewController to be a UINavigationController.

How to Create SMS Ballon iPhone Table View

I was working on incorporating an "sms ballon" type view for a client and while doing some research on the best, and different, ways to implement the functionality I came across a great tutorial, but thought it could be cleaned up just a little bit which should make your FPS increase and I fixed some memory leaks.  I wasn't able to run any performance tests on it so I would welcome ANY feedback how to improve the code.

The key to making the "ballon" background grow and shrink based upon the amount of text is using:

UIImage *balloon = [[UIImage imageNamed:self.imgName] stretchableImageWithLeftCapWidth:24 topCapHeight:15];

If someone has any advice on how to make the font look better please let me know.

UILocalNotification Example Project Using iOS4

One of the greatest new features that is included in iOS4 is the power that developers have to deliver local notifications.  At the time that the first beta was released in April I was writing specs/requirements and project timeline for a potential app which would have ended up taking me about 5 months to develop.  A large part of the project schedule dealt with having to setup/maintain user reminder preferences...the number of reminders, frequency of each one, time zones, etc.  I tried to think of ever solution that I could that didn't involve the server component, but there really wasn't any other way.

UILocationNotification to the rescue.  After looking over the API docs, Apple had provided exactly what I needed and I was able to cut out 2.5 months from the project schedule because of it.

I was able to create an POC app using UILocationNotifications in literally 5 minutes.  It involved two easy steps:


  1. In the app delegate class I added the following method to verify that the event was fired off if the app was running. -(void)application:(UIApplication *)application didReceiveLocationNotification:(UILocationNotification *)notification;
  2. In the -(void) viewDidLoad method of my controller you alloc/init a new UILocationNotification object, set the fireDate which is an NSDate object, what time zone you want, what the notification message(body) should be and then add the UILocationNotification object to the UIApplication scheduleLocalNotification method


There are two possible end results.  The first being that the event is fired off while the app is running in which case you will not see anything. Hence, why I added the NSLog to the didReceiveLocationNotification method.  The second is if you close the app before the notification has fired and in that case you will receive the alert box with your message.

Download XCode Project

Note: This was compiled with iOS4 GM and tested on iPhone 3G/3GS

Facebook Graph API with a Native iPhone Application

One of the biggest gripes that I have with working with the FBConnect iPhone SDK, and really the Facebook API, in general was having to deal with a very inefficient REST implementation.  Callback after callback, protocol after protocol, major bugs (that have yet to be fixed as far as I know), and my biggest issue is the nasty user experience having to login a user.  I was very excited to hear when last month Facebook announced they had came out with a new API that would allow great security, ease and flexibility.  The pains of having to go through currently working functionality and refactor the code to accommodate the new features wasn't too much of a problem for me because it would mean a reduced code set on my part and I would be able to get rid of the Facebook Connect SDK.  I set out to test my theories and functionality via a quick web app.  No problems.  Then I proceeded over to my native iPhone app.  EraseUrX v2.0.  The new authentication mechanism utilized in Open Graph is OAuth2.0.  While many of the headaches and complexities of using OAuth are addressed and the documentation for using it in a mobile web app are well documented with Facebook they TOTALLY dropped the ball on providing any direction on using it with a native iPhone app and they don't provide an updated SDK.

I could one of three things: 1. Use the old Facebook Connect which should still work for the forseeable future, but as stated above has too many issues that I don't want to deal with and they could drop support at any moment. 2. Wait for Facebook to publish a new SDK, but how long would it take them 3. Just figure it out myself and have a flexible solution that didn't relay any third party framework.  I went with option 3.
The first thing you need to do is setup your app with Facebook.  Second, you will need to create a "callback" page that Facebook will send the request back to once the appropriate code and token has been given to your original request.  Third, once you have gotten the access_token from Facebook then you need to put it in a DOM object. This is important so that you can retrieve it via the UIWebview's javascript string evaluation and then finally save the access_token in NSUserDefaults for any subsequent requests.  In my case I wanted to get a list of the currently logged in friends.  Instead of having to go through the callbacks and delegate methods associated with the FBConnect SDK I now have user's login via OAuth and I make a call to, https://graph.facebook.com/me/friends, and get a JSON response of what I need.  Simple. Beautiful.
Callback Example (PHP):

Custom ViewController (I am not including setting up the uiwebview. I assume you already know how to do that):

Create Custom Sized UITableView with Header and Footer Views

I am currently working on a photo gallery/slideshow app and one of the requirements is for the main gallery listing page to have static header and footer that shows the app name, contact information and adverts.  The logical first method of attack is to just setup a UITableViewController subclass, slap some views and subviews to the table view header and footer and get on with the day.  However, the table itself should scroll, but the "header" and "footer" views should remain stationary.  My first approach, I found out quickly, did not work.  Surprisingly, there are a lot of people having issues with custom sized uitableviews in general and the discussions that I saw online didn't provide a very straight forward solution so I decided to create one.

The first big problem that most people run into is that they can't seem to resize the uitableview no matter what frame size they set.  It doesn't matter if you do it programmatically or through Interface Builder it still takes up the ENTIRE screen.  That is because they have subclassed UITableViewController.  To be honest I am not sure that happens "under the covers", but the custom frame sizes/locations are ignored.  You must make your controller a subclass of UIViewController and then add your UITableView as a subview to the your controllers view.

For example:

At this point your frame size and height will be respected.

In my example I setup a simple UINavigationController project with two controllers.  The first has a header view, footer view and uitableview.  The second "detail" controller just has a UILabel with placeholder text.  Everything is built programmatically so that you can adjust frames and positions easily as well as any other customizations you would like.  Comments/suggestions are always appreciated.

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