NSArray*arr =[...load up with data...];
[[TTNavigator navigator] openURLAction:[[TTURLAction actionWithURLPath:@"tt://restaurant/Chotchkie's"]
applyQuery:[NSDictionary dictionaryWithObject:arr forKey:@"arrayData"]]];
-(id) initWithName:(NSString*)name query:(NSDictionary*)query 
{
  for(MyObject* item in[query objectForKey:@"arrayData"])
  //... do something with item ...
}

// ...

}

But, what happens when you only want to pass the query parameter?

 - (id)initWithNavigatorURL:(NSURL*)URL query:(NSDictionary*)query

Obvious right!

Thanks StackOverflow

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.

Following is a very simple view based project, that will demonstrate animating view with keyboard slide up/down.
But first, let’s see the problem. If you don’t change your view positioning when the keyboard becomes visible, basically you are likely to get something like this:

To fix that, what should be done is to listen the keyboard slide up/down notifications through the NSNotificationCenter, which viewWillAppear is a good place to start listening these two notifications.

-(void)viewWillAppear:(BOOL)animated
{
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(slideUpView:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(slideDownView:) name:UIKeyboardWillHideNotification object:nil];
}

Second step is to change the positioning of the components according to the animation of the keyboard. The following methods are called when there is a notification from the keyboard:

-(void)slideDownView:(NSNotification*)notification
{
	[[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] getValue:&animationCurve];
    [[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] getValue:&animationDuration];
    [[[notification userInfo] objectForKey:UIKeyboardBoundsUserInfoKey] getValue:&keyboardFrame];

	[UIView animateWithDuration:animationDuration
				delay:0.0
				options:animationCurve
				animations:^{
					self.view.frame = CGRectMake(0, 0, 320, 480);
				}
				completion:^(BOOL finished){
					NSLog(@"Slide down Done..!");
				}];
}

-(void)slideUpView:(NSNotification*)notification
{
    [[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] getValue:&animationCurve];
    [[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] getValue:&animationDuration];
    [[[notification userInfo] objectForKey:UIKeyboardBoundsUserInfoKey] getValue:&keyboardFrame];
	//
	[UIView animateWithDuration:animationDuration
				delay:0.0
				options:animationCurve
				animations:^{
					self.view.frame = CGRectMake(0, -keyboardFrame.size.height + 70, 320, 416);
				}
				completion:^(BOOL finished){
					NSLog(@"Slide up Done..!");
				}];
}

Don’t forget to add .h file the following declarations:

// in controller's .h file
NSTimeInterval animationDuration;
UIViewAnimationCurve animationCurve;
CGRect keyboardFrame;

The final result is something like this

note 1: Feel free to download the source code (link). It also includes the slide down via the button.
note 2: The licence to this peace of code is Beerware, In short, “Should the user of the product meet the author and consider the software useful, he is encouraged to buy the author a beer ‘in return’ (or, in some variations, drink a beer in the author’s honor).”

What you need to do in three steps is that

• Sign up to AWS, connect to AWS (preferable with Amazon EC2 API Tools)
• Create an instance (via API tools or the web console)
• Connect to that instance via SSH.

These are the steps that works for me,

1. Sign up AWS — http://aws.amazon.com/

2. Follow the steps at that link, and create X.509 certificate (also download private key when doing that)

3. Create an instance from the https://console.aws.amazon.com/ec2/ (Don’t forget to save the private key .pem file while creating the instance)

5. Follow the steps here http://paulstamatiou.com/how-to-getting-started-with-amazon-ec2 for connecting to the instance via SSH.

Links that helps

- AWS console – https://console.aws.amazon.com/ec2/

- AWS portal — https://aws-portal.amazon.com/

- Starting Amazon EC2 with Mac OS X — http://www.robertsosinski.com/2008/01/26/starting-amazon-ec2-with-mac-os-x/

- How To: Getting Started with Amazon EC2 — http://paulstamatiou.com/how-to-getting-started-with-amazon-ec2

- Connect to Your Linux/UNIX Instance — http://docs.amazonwebservices.com/AWSEC2/latest/GettingStartedGuide/

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

gem 'aws-s3'

bundle install

development:
  bucket: bucket-dev
  access_key_id: xxx
  secret_access_key: xxx
test:
  bucket: bucket-test
  access_key_id: xxx
  secret_access_key: xxx
production:
  bucket: bucket-pro
  access_key_id: xxx
  secret_access_key: xxx

  #paperclip
  has_attached_file :photo,
       :styles => {
       :thumb=> "100x100#",
       :small  => "400x400>" },
     :storage => :s3,
     :s3_credentials => "#{RAILS_ROOT}/config/s3.yml",
     :path => "/:style/:id/:filename"

That’s it! Simple isn’t it.

links that might help

From this link, you can find the steps for creating a Rails project from scratch with paperclip.
http://jameswilding.net/2010/07/24/paperclip-rails-3/

As I have already had a project that needs file attachments, I follow a slightly different path.

The steps for adding a file attachment is as follows:

1. Install Paperclip

$ rails plugin install git://github.com/thoughtbot/paperclip.git

2. Add image attribute to your model

  #paperclip
  has_attached_file :photo,
     :styles => {
       :thumb=> "100x100#",
       :small  => "400x400>" }

3. Create migration file and add the necessary columns to your database

$ rails generate migration add_photo_to_microposts photo_file_name:string photo_content_type:string photo_file_size:integer

rake db:migrate

4. Change you form

<%= form_for @micropost  , :html => { :multipart => true } do |f| %>
  <%= f.file_field :photo %>
  ...

5. Change view that will show the uploaded image (optional)

<% if micropost.photo.exists? then %>
	<%= image_tag micropost.photo.url(:small) %>
<% end %>

That’s it. It is done.

For etohum admin application we used gae/j and it has been almost two years and gae/j has been improved a lot, but still, it has some really annoying features (bugs — I am not sure how to named them).

This time, it is the Datastore Indexes. Some of the pages requires indexes like

which turns out to be confusing for the auto generation tool. If, let’s say, you change the order of the last two fields,

like this

you will not get it automatically.

Even if you explicitly define it in your  datastore-indexes.xml file

<datastore-index kind="Application" ancestor="false" source="manual">
 <property name="applciationIsFinished" direction="asc"/>
 <property name="isSpam" direction="asc"/>
 <property name="sezonId" direction="asc"/>
 <property name="bitisTarihi" direction="desc"/>
 <property name="basvuruTarihi" direction="desc"/>
 </datastore-index>

And the workaround for the problem is stated in the last paragraph of Using Automatic Index Configuration documentation

It’s a good idea to occasionally move index configuration from datastore-indexes-auto.xml to datastore-indexes.xml, then disable automatic index configuration and test your app in the development server. This makes it easy to maintain indexes without having to manage two files, and ensures that your testing will reproduce errors caused by missing index configuration.

So change the datastore-indexes.xml file and add manually the all required indexes and upload the application.

<datastore-indexes autoGenerate="false">

You can change it back to auto generate after make sure the desired indexes are created.

ps. A tip about gae/j is that it is considerable faster when it is 4AM-7AM at the west coast of North America.

In UIDevice class , you see the following orientations:

typedef enum
{
    UIDeviceOrientationUnknown,
    UIDeviceOrientationPortrait,            // Device oriented vertically, home button on the bottom
    UIDeviceOrientationPortraitUpsideDown,  // Device oriented vertically, home button on the top
    UIDeviceOrientationLandscapeLeft,       // Device oriented horizontally, home button on the right
    UIDeviceOrientationLandscapeRight,      // Device oriented horizontally, home button on the left
    UIDeviceOrientationFaceUp,              // Device oriented flat, face up
    UIDeviceOrientationFaceDown             // Device oriented flat, face down
} UIDeviceOrientation;

But for a view controller’s parent, there are only four

self.parentViewController.interfaceOrientation only has

typedef enum
{
    UIInterfaceOrientationPortrait           = UIDeviceOrientationPortrait,
    UIInterfaceOrientationPortraitUpsideDown = UIDeviceOrientationPortraitUpsideDown,
    UIInterfaceOrientationLandscapeLeft      = UIDeviceOrientationLandscapeRight,
    UIInterfaceOrientationLandscapeRight     = UIDeviceOrientationLandscapeLeft
} UIInterfaceOrientation;

So the problem arises when you try to layout according to

  [UIDevice currentDevice].orientation

When the device orientation is UIDeviceOrientationFaceUp or UIDeviceOrientationFaceDown, you get 3 orientation changed calls. One is the up and down, than a landscape, than again up or down.

This is, to be honest, completely broken. It is clear that, since the status bar can be located to four locations on the screen, there should be 4 device orientations, not 6. The FaceUp and FaceDown should be a different property I guess (gravityOrientation or sth like that)

ps. Some links that can help if you have issues with this up&down thing

• Handling UIDeviceOrientationFaceUp & UIDeviceOrientationFaceDown
• http://www.cocos2d-iphone.org/forum/topic/6413
• http://www.iphonedevsdk.com/forum/iphone-sdk-development/45799-ipad-device-orientation-face-up.html

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);

}