Recently, I was working on a game with Cocos2d and keep getting this weird iOS version problem. On iOS 5, all my labels were shown as expected but on iOS 4 labels somehow kept disappearing. First I thought this is because of the retina display and point/pixels stuff. However, it was because of the fonts I was using. HelveticaNeue-CondensedBold and HelveticaNeue-CondensedBlack are available on iOS 5, but not on iOS 4 (http://iosfonts.com/).

I googled to see how easy to add custom fonts and it turned out, it is super easy.

These are the links I found helpful:

• Adding custom fonts by Dave Allanson (link)
• Using Custom Fonts by M. Arsalan Anwar (link)

If you get the fonts from Adobe, we will get a drawing problem like mentioned here. You need to follow the steps here, change the font file’s ascender property. Don’t worry it is not that scary as it seems Don’t forget to install Apple Font Tool Suite from here.

After this short happy talk, here is the code snippet that saves your UIImage to the Documents folder with its alpha channel, if there is one. The other method is for reading that image back to an UIImage instance.

-(void)saveImageToDocs:(NSString *)fileName
{
	NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
	NSString *documentsDirectory = [paths objectAtIndex:0];
	NSString *filePath2 = [NSString stringWithFormat:@"%@/%@.png", documentsDirectory, fileName];

	// If you use this method, the transparency will be lost
	//NSData* imageData = UIImageJPEGRepresentation(drawImage.image, 1.0);
	//NSData* imageData = UIImagePNGRepresentation(drawImage.image);
	//[imageData writeToFile:filePath2 atomically:NO];

	// So use this one
	[UIImagePNGRepresentation(myUIImage) writeToFile:filePath2 atomically:YES];
}

-(void)loadImageFromDocs:(NSString *)fileName
{
	NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
	NSString *documentsDirectory = [paths objectAtIndex:0];
	NSString *filePath2 = [NSString stringWithFormat:@"%@/%@.png", documentsDirectory, fileName];
	if([[NSFileManager defaultManager] fileExistsAtPath:filePath2])
	{
		NSLog(@"image file exists");
		myUIImage = [UIImage imageWithContentsOfFile: filePath2];
	}
}

Below you can find the summary of available alternatives for storing data on iOS based machines. Mainly, which one to use depends on your needs like size of data, need of concurrency, access speed, etc.

• NSUserDefaults
  • Based on plists
  • Store lightweight app state
  • Tutorial (link)
• Plist — Writing everything out as a plist
  • Not suitable for complex model objects
  • Faster than NSUserDefaults
  • How to load a plist (link)
  • Write & Read data to .plist (link)
• Archived Objects
  • Conteptual guide (link)
  • Archives provide a means to convert objects and values into an architecture-independent stream of bytes that preserves the identity of and the relationships between the objects and values.
  • Serialization converts Objective-C types to and from an architecture-independent byte stream. In contrast to archiving, basic serialization does not record the data type of the values nor the relationships between them; only the values themselves are recorded. Arbitrary objects cannot be serialized. Only instances of NSArray, NSDictionary, NSString, NSDate, NSNumber, and NSData (and some of their subclasses) can be serialized. (link)
  • Forum post about how to use archiver (link)
• The joy of SQLite
  • Basically a local file act like a database server
  • Not very good for extreme concurrent access
  • A step by step tutorial (link)
• Core Data
  • Higher abstraction layer than SQLite
  • Save&load model objects
  • ORM (Rails ActiveRecord, Java Hibernate)
  • Use NSPredicate for in memory filtering
  • Apple Dev Center Article (link)
• Web Services
  • Store & access remote data
  • XML and Json parsers

ps. Related Stackoverflow entry

Here are the alternatives (List of Audio APIs) –

• System Sound API — very short – limited file type – no control
• AVAudioPlayer class — objC
• Audio Toolbox — recording – streaming – controls
• Audio Units — audio processing
• OpenAL — 3D positional sound (Yes, just like OpenGL)

Since what I need is just to play a short audio clip w/out any looping or any other control, I choose System Audio API.

As always, Google is the first address to ask howto use System Audio AP, How To Play Audio With The iPhone SDK is a step by step guide, but it takes the starting point from a sample code project from Apple, which is no longer available.

Another one is the sample code project SysSound which contains an iOS4 specific feature so that it will not work on iPad.

So how to play an audio clip w/out hassling that much?

Here is the code snippet : (don’t forget to add the AudioToolbox framework)
#include
….

-(void)playSound
{
	SystemSoundID shortSound;
	NSURL* audioFile = [NSURL fileURLWithPath:[[NSBundle mainBundle]
				pathForResource:[NSString stringWithFormat:@"filename"] ofType:@"wav"]];
	AudioServicesCreateSystemSoundID((CFURLRef)audioFile, &shortSound); 

	//playing it
	AudioServicesPlaySystemSound(shortSound);

	//cleanup
	AudioServicesDisposeSystemSoundID(shortSound);

}

• http://stackoverflow.com/questions/1143589/what-is-the-pastrykit-framework
• http://daringfireball.net/2009/12/pastrykit
• http://ajaxian.com/archives/pastrykit-an-iphone-webdev-library-from-apple

Sencha Touch — you should definitely see their kitchen sink, it is pretty cool.but there is no commercial license yet.

• http://ajaxian.com/archives/sencha-touch
• http://mobile.tutsplus.com/articles/news/sencha-touch-html5-mobile-framework/
• http://www.endofnative.com/

iUi — not that many people using it I guess. I build a site with it, if it is sth fast and easy to learn, iUi can do the job.

• Sites build with iUi — http://code.google.com/p/iui/wiki/PoweredBy

jqtouch — demos seem very nice, probably better than iUi in terms of current release capabilities and size of community.

iWebkit — demo seems promising, but not ready for prime time.

SproutCore — not for iPhone specificly, but its demo seems nice.

So my choice for the next task is jqtouch. not iui this time.

Since finding a good starter document is a very important decision, I took my time to select my first RoR source. I went over the following books and decided to use the latter one:

• Ruby on Rails For Dummies
• Sitepoint Simply Rails 2nd Edition
• Beginning Ruby on Rails
• The Ruby on Rails Tutorial Book

Although it is called as a tutorial, when you get the pdf dump, the 12 chapter tutorial is approximately 500 pages, which is literally a book.

The language of the book is very clean and most of the time funny. You can easily develop the code when you are reading it.  You can also follow a test driven approach if you want, but you don’t have (I didn’t).

I finished the book in 7 days with a daily 4 hours concentrated reading/coding sessions and with lots of Starbucks Misto (thanks Starbucks Besevler crew!).

The final code is at Github, and live demo site at Heroku.

As a pointer for the further steps, the tutorial suggest some pointers but I prefer to go on with my path, which requires ImageMagick and Paperclip, so next post will be about these two.

See you next time!

ps. I really like Heroku. Grails has something similar but to be honest, it is not that magical (as in iPad).

After 3 nights the application was ready for the submission. It got rejected since I didn’t read the iPad User guidelines carefully (actually I just skimmed it in 5 minutes). The rejection reason is “You can’t show more than one popover at the same time”. I fixed the problem, and it is available in the app store (App Store link)

I will probably change the default RSS feed of Hackernews which only show top 30 posts. Probably something on GAE, and maybe a simple my favorites kind of thing.