Reveal app shows more UI details than xcode

Reveal is an app that you can get (from here) that can take a snapshot of your running app and show all the items that are in it, even if they are hidden or in the background. xcode does have "debug view hierarchy" that does a pretty good job but if you need more detail than that, reveal is for you.

In the latest xcode (7) there is a bit of a connection problem. Specifically with the plugin as it was made for xcode 5 it seems. So to manually get reveal connected to your simulation, you can pause the app while it is running and run the command in the debug commands (lldb);

expr (void*)dlopen("/Applications/Reveal.app/Contents/SharedSupport/iOS-Libraries/libReveal.dylib", 0x2);

expr [(NSNotificationCenter*)[NSNotificationCenter defaultCenter] postNotificationName:@"IBARevealRequestStart" object:nil];

continue;

You might need to enter each line one at a time for it to work. 

After that, you should be able to goto the reveal app, attach it to the simulator and hit the refresh button and tada!

iOS KVO explained or How Key Value Observations work

There are so many ways to transfer data between objects. delegate, blocks, notifications, etc. Understanding them and how to use them properly is one of the most critical aspects of developing apps. Which ones should I used and why is very important. With that being said, here is one more that I've used many times before but always seemed to avoid really understanding, until now. KVO.

Key-Value Observing (KVO) is another way to learn about other objects without them really offering it up easily. The basis of this technique is if you want to know when a value of a different object changes you can create a KVO to detect and inform you of when this actually happens. Many apple APIs use this like AVPlayer. Personally I am not a big fan but I can appreciate why it is used.

Lets get down to it. Here is the declaration;

 [object addObserver:(NSObject *)anObserver
         forKeyPath:(NSString *)keyPath
            options:(NSKeyValueObservingOptions)options
            context:(void *)context];

-object is the object you want to observe the change on
-anObserver should whom you want to be listening, usually self.
-keyPath is the name of the property you want to listen for. Example is when a label text changes you would put in @"text"
-options is for when it actually changes, what do you want back. There are 4 options of which you can choose multiple;    
    NSKeyValueObservingOptionNew = 0x01, when you want what the new value is
    NSKeyValueObservingOptionOld = 0x02, when you want what the old value was
    NSKeyValueObservingOptionInitial = 0x04, when you want to know before it happens
    NSKeyValueObservingOptionPrior  = 0x08 when you want to know after it happens (can't get the old one then)
-context is a unique identifier that you can reference when the call back method is actually called. I needs to be unique and nothing else. So people like to get creative with this sometimes. Most of the time I see something like this;

static void *AVPlayerDemoPlaybackViewControllerStatusObservationContext = &AVPlayerDemoPlaybackViewControllerStatusObservationContext;

This is just a pointer that references itself. It is small and unique so it fits perfectly. And when you want to find it, you can do so easily. 

Now that you are listening, now what? How do I actually do something? Well you need to run the actually method it plans to run when it needs to of course. It is;

- (void)observeValueForKeyPath:(NSString*) path

                      ofObject:(id)object

                        change:(NSDictionary*)change

                       context:(void*)context

-path is the string you want

-object is the actual object 

-change is a dictionary of the items you requested

-context is that unique context you created above

Since this method is called for all value changes you should isolate what you are looking for each time by referencing path, context and/or object. Once you have done that, grab the change dictionary and see what was actually changed. 

Note: Most of the time you want to compare the new and old one when you get them to make sure it was not actually just updated with the same thing twice.

   if (context == AVPlayerDemoPlaybackViewControllerStatusObservationContext){
        AVPlayerItemStatus status = [[change objectForKey:NSKeyValueChangeNewKey] integerValue];
        self.streamStatusType = StreamStatusTypeUnknownState;
        switch (status){
            case AVPlayerItemStatusUnknown:{
                self.streamStatusType = StreamStatusTypeUnknownState;
                break;
            }
            case AVPlayerItemStatusReadyToPlay:{
                self.streamStatusType = StreamStatusTypeReadyToPlay;
                break;
            }
            case AVPlayerItemStatusFailed: {
                self.streamStatusType = StreamStatusTypeFailed;
                break;
            }
        }
     }

And that is about it!

Bonus note: removing the observer can actually crash the app randomly is seems so it is good practice to add a @try @catch around it just in case.

        @try {

            [self.playerItem removeObserver:self forKeyPath:@"status"];

        }

        @catch (NSException *exception) {

            

        }

        @finally {

            

        }

References:
Apple KVO intro
Apple KVO example

How to make a 3D planet in xcode using SceneKit

For some reason I've always wanted to create a spinning 3D globe but never had the time or ability. I decided last weekend to see if I could find someone or some way to make one. I checked all the usual places but the few I found were either overly complicated, way out of date, or no longer worked. So I decided to put my hat in the ring. I thought this might also be a good way to play with scenekit since I have never touched it before.

Wow. It worked better than I could ever imagine. Here is how to make the whole world in a few steps and about 15 lines of code.

First create a new project using scene kit. I like objective-c but you can do whatever you want with the language. You should be able to run it right away and see an airplane that you can move around the screen in 3 dimensions. Don't worry about that.

Here is the quick code;

-(void)worldSetup{

    SCNView *scnView = (SCNView *)self.view;

    

    myScene = [[SCNScene alloc] init];

    

    SCNSphere *planetSphere = [SCNSphere sphereWithRadius:5.0];

    SCNNode *sphereNode = [SCNNode nodeWithGeometry:planetSphere];

    [myScene.rootNode addChildNode:sphereNode];

    

    SCNMaterial *corona = [SCNMaterial material];

    corona.diffuse.contents = [UIImage imageNamed:@"earth"];

    corona.specular.contents = [UIColor colorWithWhite:0.6 alpha:1.0];

    corona.shininess = 0.5;

    [planetSphere removeMaterialAtIndex:0];

    planetSphere.materials = @[corona];

    

    // create and add a light to the scene

    scnView.autoenablesDefaultLighting = YES;

    

    // create and add a camera to the scene

    scnView.allowsCameraControl = true;

    

    mySphere = planetSphere;

    

    scnView.scene = myScene;
}

earth

in celebration of seeing pluto,
I added some love

Here is the alternate slightly more custom code.

-(void)worldSetup{

    SCNView *scnView = (SCNView *)self.view;

    

    myScene = [[SCNScene alloc] init];

    

    SCNSphere *planetSphere = [SCNSphere sphereWithRadius:5.0];

    SCNNode *sphereNode = [SCNNode nodeWithGeometry:planetSphere];

    [myScene.rootNode addChildNode:sphereNode];

    

    SCNMaterial *corona = [SCNMaterial material];

    corona.diffuse.contents = [UIImage imageNamed:@"earth"];

    corona.specular.contents = [UIColor colorWithWhite:0.6 alpha:1.0];

    corona.shininess = 0.5;

    [planetSphere removeMaterialAtIndex:0];

    planetSphere.materials = @[corona];

    

    // create and add a light to the scene

    SCNNode *lightNode = [SCNNode node];

    lightNode.light = [SCNLight light];

    lightNode.light.type = SCNLightTypeAmbient;

    lightNode.light.color = [UIColor colorWithWhite:0.37 alpha:1.0];

    lightNode.position = SCNVector3Make(0, 50, 50);

    [myScene.rootNode addChildNode:lightNode];

    

    SCNNode *omniLightNode = [SCNNode node];

    omniLightNode.light = [SCNLight light];

    omniLightNode.light.type = SCNLightTypeOmni;

    omniLightNode.light.color = [UIColor colorWithWhite:.70 alpha:1.0];

    omniLightNode.position = SCNVector3Make(0, 40, 40);

    [myScene.rootNode addChildNode:omniLightNode];

    

    // create and add a camera to the scene

    scnView.allowsCameraControl = true;

    

    // create and add a camera to the scene

    SCNNode *cameraNode = [SCNNode node];

    cameraNode.camera = [SCNCamera camera];

    cameraNode.position = SCNVector3Make(0, 0, 20);

    [myScene.rootNode addChildNode:cameraNode];

    

    mySphere = planetSphere;

    

    scnView.scene = myScene;

}

You still need to get an 'earth' texture from the internet somewhere, should be easy to find, probably from NASA. And that is it!

Here is a link to the app in github. https://github.com/Darkin/3DPlanet

Helpful CocoaPods

The classic and helpful AFNetworking
Github - CocoaPod pod "AFNetworking", "~> 2.0"

The robust and powerful JSON data network restful RESTKIT
Github - CocoaPod pod 'RestKit', '~> 0.24.0'
                                # Testing and Search are optional components
                                pod 'RestKit/Testing', '~> 0.24.0'
                                pod 'RestKit/Search',  '~> 0.24.0'

The nice JSON to/from NSDictionary template MANTLE
Github - CocoaPod  pod 'Mantle', '~>2.0.2'

The pretty much required facebook 1 2 3
Github - CocoaPod 'FBSDKCoreKit', 'FBSDKLoginKit', 'FBSDKShareKit' .

The ever helpful image downloader and cacher SDWebImage
Github - CocoaPod pod 'SDWebImage', '~>3.7'

Random Storyboard Autolayout Situational Help

I'm just going to put random helpful links here that explain how to perform certain tasks in the xcode storyboard that might be helpful.

- Spreading out Items (like UIButtons) evenly. Helps to put them all in a separate UIView as well so you can move them all together.

- Simple Getting Started Tutorial with font sizing. Helps understand constraints that only work in certain devices as well as a nice font sizing section.

-How to unwind a segue with the push of a button. Frustrating if you don't know it. Explains how to setup and properly close a segue from any parent view controller. There is a programmatic version here.

Using CocoaPods and setting up Facebook SDK 4.1 in an xcode workspace in iOS8

Cocoapods are the new external framework. They are easy to setup, easy to update and easy to incorporate... one you have done it a few times. The most common external framework people use is the FacebookSDK. I will walk you through the basics of setting up a xcode workspace that incorporates the new facebookSDK which are now three parts; 'FBSDKCoreKit', 'FBSDKLoginKit', and 'FBSDKShareKit'.

I will probably go through some basic facebook usage in another post... maybe.

First you need to setup cocoapods. If you have not done so already, go into a terminal from your launchpad/utilities and type;
 $ sudo gem install cocoapods
This should use your integrated Ruby and setup cocoapods so you can use them whenever you want. It will most likely ask for your computer password and give you a warning but that is normal. Your mac should then  install a bunch of files and you are off to the races.

Next you will need to setup a work location. To be clean, create a new folder for your new app.
$ mkdir NewApp
$ cd NewApp
$ touch Podfile

You should be in your new app folder and in that folder should be an empty file called Podfile. This file is the instructions for cocoapods on what pods you want installed for this particular app. Since we want the app to have the new facebook pods installed, open up the Podfile in whichever prefered editor you want and copy this in;

source 'https://github.com/CocoaPods/Specs.git'
xcodeproj 'NewApp'
platform :ios, '7.0'
#Facebook Stuff
pod 'FBSDKCoreKit', '~> 4.1'
pod 'FBSDKLoginKit', '~> 4.1'
pod 'FBSDKShareKit', '~> 4.1'

What this does; The first line is to tell Cocoapods where on the internet you wish to look for the pods. The second line says what project you want your pods to work with. The third line says what target you want to setup. The lines with a # at the beginning are just comments and the last three lines are the actual facebook pods you wish to install into your workspace. Close this up and open up xcode.

In xcode, create a new project called NewApp (or whatever you decided to call it in the other areas) and put it in the same directory as the Podfile. Now go back to your terminal session and type;
$pod install

If everything was done correctly, you should see some green command lines installing the facebook pods and then the folder should also have a new xcworkspace file. Open up that file and you should see both your project and and 'Pods' in your workspace directory in xcode.

And you are done!

Why do this? Well, not only can you copy and paste this into all future projects but you can also update the pods at any point by just typing 'pod install' or 'pod update'. You can also create your own local pods and do the same thing. The way to do that is just specify a local directory for the pod you wish to incorporate;

#pod 'D2TSounds', :path => '/Users/yourname/Documents/CocoaPods/D2TSounds'

You might need to do a little setup for the local files but if you have several items that you use a lot, this will save you a lot of time in the long run.

Helpful links;
Cocoapods initial setup
Cocoapod pod link page
Facebook Login
Facebook Sharing
Facebook App Links
Facebook Graph API

Setting and Testing localizations in iOS 6

To Set:
http://stackoverflow.com/questions/5349066/how-to-localize-my-app-with-xcode-4

7) in your code use  NSLocalizedString(@"TEST", @"test") where the first arg is the string and the second arg is the description (optional can be nil)
1) Create strings file

2) call it "Localizable.strings"
3) fill the localizable.string with all the english terms you use in the app "TEST" = "TEST";
4) file inspector "Make Localized"
5) + add localization you want
6) add only the localizable.strings file to the list
8) translate and smile

To Test:
http://useyourloaf.com/blog/2013/07/22/using-launch-arguments-to-test-localizations.html

1) go into the current Scheme
2) goto arguments
3) add "-AppleLanguages (Russian)" without quotes
4) click on and off to test the various languages and smile

iOS Creating Custom Delegates in iOS6 with ARC

So you want two Objects to talk to each other more than a little bit? Here is what to do by example.  Lets say we have our MainViewController and a new SearchViewController that you want a delegate attached to it. This is all you need to do.

In SearchViewController.h

@protocol SearchViewDelegate <NSObject>

@optional

@required

-(void)didAskToSearch:(NSString*)string;

@end

@interface SearchViewController : UIViewController {

}

@property (nonatomic, assign) id <SearchViewDelegate> delegate;

@end

optional has non-required methods and required of course has required methods. 

In SearchViewController.m;

    [_delegate didAskToSearch: [self searchRequestDetails]];

this is put anywhere in the code when you want it to send the information back to the other object. 

In the MainViewController.h;

@interface MainViewController : UIViewController <SearchViewDelegate> {

}

In MainViewController.m;

SearchViewController *searcher = [[SearchViewController alloc]init];

searcher.delegate = self;

#pragma mark - SearchViewControllerDelegates

-(void)didAskToSearch:(NSString*)string{

     //do whatever you want with the string results

}

When creating the object, make sure the tell the delegate you have those methods. Then you just have to create the methods as per it is required. 

Helpful link
http://stackoverflow.com/questions/12020539/how-to-make-custom-delegate-in-ios-app

Programmatically Adding UINavigationController to existing app in iOS 6 with ARC

Whenever you build an app, you think you know how it should be structured. How are the views going to be layed out for the user to see. However, sometimes designs have to change (Mostly because the client keeps a moving target). How can you add that very helpful Navigation Controller into an existing app quickly and easily...

First, don't panic. It is actually quite easy. the guys at apple feel your pain and tried to make this as confortable as possible. 

In the AppDelegate.m;

    UINavigationController *navCtrlr = [[UINavigationController alloc]initWithRootViewController:self.viewController];

    [self.window setRootViewController:navCtrlr];

Where "self.viewController" is your existing viewController that has your first view. 

Done. 

Thats it. 

Ta Da!

now all you need to do is go through your code and turn the "addSubview" to this;

     [self.navigationController pushViewController:_detailViewController animated:YES];

Where "_detailViewController" is your next view in the stack you want to view. 

As you know, navigationController has a auto back button, but if you want to do it manually;

 [self.navigationController popViewControllerAnimated:YES];

or

 [self.navigationController popToRootViewControllerAnimated:YES];

if you want to go all the way back to the beginning. 

Other quick cosmetic items you can do is;

-(void) viewWillAppear:(BOOL)animated{

    self.title = @"My Title";

    self.navigationController.navigationBarHidden = NO;

}

Which will let you change the title on the NavBar. And make sure it is not hidden.

- (void)viewDidLoad{

    [super viewDidLoad];

    [self.navigationController.navigationBar setBarStyle:UIBarStyleBlack];

}

Which will let you change the colour of the NavBar. 

There is a lot more that can be done, but I hope that gets you off the ground and in the right direction. 

Here is an add on that looks interesting;
iOS Open Source: Drop-Down Navigation Menu