Friday, August 19, 2011

My take on Android vs iPhone development




As a mobile application developer I would like to share my experience with iOS and Android so far. At the end of this post I will rate my developer experience with each of the OSs and announce my favorite mobile OS!

I began my mobile application development experience with iOS. Coming from a Java programming background venturing into the murky waters of Objective C was a bit scary at first (I'd never even heard of Objective C until I looked into iOS). All I knew when starting off with Objective C was that it was a language similar to C and C++. That meant having to deal with memory pointers and no one who is a fan of Java and its garbage collector likes meddling with pointers again. Fortunately iOS apps are built around the MVC (Model-View-Controller design pattern), which meant there were standardized ways for dealing with pointers, you just needed to follow some routines and rules. But it isn't always easy.

But once I had got the hang of Objective C syntax and the Apple iOS API, things became a lot more easier. My favorite part of iOS development was using Interface Builder. The latest version of Xcode has this interface designer built into Xcode and it makes designing great looking iphone apps a breeze! Some developers prefer designing their UIs programmatically because that allows them to reuse design code in multiple apps but using interface builder makes the task of UI design much faster! The iOS API has practically every UI widget you can want on an app already available. So that makes your UI design task so much easier. I personally think the iOS UI widgets are much prettier than the current android widgets. Maybe because Steve Jobs is more peculiar about UI design than the folks at Google. So in conclusion for my take on iOS development I would say that what I like about it is the ease with which I can develop better looking UIs.

As for Android development I started off here doing an experimental app (which is now on the Android Market!:) ). My biggest complaint when trying out Android development was that at the time I started off I didn't own an Android handset. This meant that I had to run all my code on the emulator. When I started developing I was using the android api8. And gosh did it have the slowest emulator ever! Thankfully Android has since then increased their emulator speeds. But its still much slower than running on an actual device. Unlike the iPhone simulator, which simulates an iOS environment running on Mac h/w, the Android emulator emulates the entire Android device enviroment (including the h/w enviroment : SD card size, memory capacity etc.). So you can't blame it for being slow. But as long as you forget the emulator and stick to using a device for running your code during development, you will have a much happier android dev experience:)

The next thing that bugged me when starting off Android development was their UI designer. I used Eclipse along with the Android plugin for development. And even the currently available plugin is quite disappointing when it comes to UI designing. If your first mobile dev experience was with Android then this may not be that big a deal. You will just learn to navigate UI design using XML and not complain about it. But if you were an Interface Builder fan switching from iOS development to Android then you will be thoroughly disappointed. Seems Android folks are developing a WYSIWYG editor for the eclipse plugin though, this should provide a better rival for Interface Builder. Also I would rate the currently available UI widgets in iOS as better than Android ones in terms of their design and also ease of use in the code. Those cons aside developing Android apps is a joy because you are dealing with Java here. If you have some development experience in Java then there is no more learning required. Best of all the garbage collector handles all the nasty memory management details for you.

So here's my final rating.. Please note that the ratings below are entirely based on my own personal evalution.

1. UI design
iOS - 9/10
Android - 7/10

2. Ease of setting up dev environment
iOS - 3/10 (you need to get a mac first! and buy an iphone too or just forget about it!)
Android - 10/10 (can be done on a pc running any OS. and all dev tools required are freely available over the interent).

3. Deployment
iOS - 6/10 (the process of deployment is so cumbersome and restricted. but on the plus side this ensures that your app is of the best possible quality. still i think Apple can do more to simplify the deployment process)
Android - 5/10 (deploying an android app to the market is a breeze. but this really lowers the quality of apps out there)

4. Developing for different devices
iOS - 10/10 ( fixed screen sizes.)
Android - 2/10 ( varying screen sizes. different device hardwares. compatibility nightmare!)

5. Development language
iOS - 5/10 (strange and repetitive syntax.)
Java - 7/10 (Java is easy to develop with but runs slower)

6. Available resources for developers
iOS - 7/10 (the NDA delays developers from getting the info they need to support upcoming iOS releases in their apps)
Android - 10/10 (opensource. hurray!)

7. Debugging
iOS - 4/10 (can be a total nightmare even with tools like NSZombie setup. write perfect code or suffer!)
Android - 9/10 ( except for the occasional system crashes which leave baffling messages android dev tools are quick to point out exactly where you made a mistake in your code)

Some simple arithmetic results in Android being placed as the winner with 7.1429/10 vs 6.2857/10 for iOS.

For more developer takes on Android vs iOS please see:

http://whereoscope.wordpress.com/2010/12/07/android-vs-ios-a-developers-perspective/

http://nfarina.com/post/8239634061/ios-to-android

Tuesday, August 9, 2011

Making sense of crash logs from iPhone apps

Ohoh your iphone app just crashed! One way to debug the crash is by inspecting the crash log. Here's how..

1. Before releasing the application for iphone you must first build your app for Archiving on xcode.
This will generate both the ProjectName.app and ProjectName.app.dSYM files. You will see the generated ProjectName.app file in the target section of the project in xcode. Selecting the 'Show in Finder' option(right click target ProjectName.app file) will reveal the location of both these required files. Copy these files to a new folder named Project_CrashDebugging.

2. Sync your iphone using itunes. Now your applications crash logs will have been copied to the computer. Generally you can find them at the following path your_home_folder_name/Library/Logs/CrashReporter/MobileDevice/your_device_name

3. Select the crash log from your project and copy it to Project_CrashDebugging folder you created earlier.

4. To demystify the crash log you will need to use the symbolicatecrash application. Typically it will be located at the following path /Developer/Platforms/iPhoneOS.platform/Developer/Library/PrivateFrameworks/DTDeviceKit.framework/Versions/A/Resources/. If not find it in your hard drive by searching for it using the locate function in console. Once you have found it copy it to one of your computers Path location (check you path locations using echo $PATH in console), generally copying /usr/bin will do. Now you can call symbolicatecrash directly from the console.

5. cd to your Project_CrashDebugging folder and now call..

symbolicatecrash crash_log_name ProjectName.app.dSYM > filename.crash

now you will have created a symbolicated filename.crash file which you can refer for debugging


Given below are parts of an example application I use to try out symbolicatecrash.

from ExampleViewController.m

- (void)viewDidLoad
{
NSString *test = [[[NSString alloc] initWithFormat:@"Test"] autorelease];
[test release];

NSLog(@"Test is: %@", test);//calling test after release will result in a crash
[super viewDidLoad];
}

from initial crash log..

Date/Time: 2011-08-10 11:09:33.253 +0530
OS Version: iPhone OS 5.0 (9A5288d)
Report Version: 104

Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x576e6f69
Crashed Thread: 0

Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libobjc.A.dylib 0x36c85fc2 0x36c82000 + 16322
1 Foundation 0x35238bb8 0x3522f000 + 39864
2 CoreFoundation 0x354e3d06 0x35454000 + 589062
3 CoreFoundation 0x35477d24 0x35454000 + 146724
4 CoreFoundation 0x354984b0 0x35454000 + 279728
5 Foundation 0x3524c914 0x3522f000 + 121108
6 Foundation 0x3524c8b4 0x3522f000 + 121012
7 Example 0x000027a4 0x1000 + 6052
8 UIKit 0x34a3c124 0x349ff000 + 250148
9 UIKit 0x34a1777a 0x349ff000 + 100218
10 UIKit 0x34b6d288 0x349ff000 + 1499784
11 Example 0x00002538 0x1000 + 5432
12 UIKit 0x34a17f1c 0x349ff000 + 102172
13 UIKit 0x34a070e6 0x349ff000 + 32998
14 UIKit 0x34a06032 0x349ff000 + 28722
15 UIKit 0x34a05ad0 0x349ff000 + 27344
16 UIKit 0x34a055ea 0x349ff000 + 26090
17 GraphicsServices 0x33f27ef4 0x33f23000 + 20212
18 CoreFoundation 0x354d79c4 0x35454000 + 539076
19 CoreFoundation 0x354d7966 0x35454000 + 538982
20 CoreFoundation 0x354d658c 0x35454000 + 533900
21 CoreFoundation 0x35478036 0x35454000 + 147510
22 CoreFoundation 0x35477efe 0x35454000 + 147198
23 UIKit 0x34a03758 0x349ff000 + 18264
24 UIKit 0x34a0098a 0x349ff000 + 6538
25 Example 0x000024ba 0x1000 + 5306
26 Example 0x00002478 0x1000 + 5240


from symbolicated crash log..

Date/Time: 2011-08-10 11:09:33.253 +0530
OS Version: iPhone OS 5.0 (9A5288d)
Report Version: 104

Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x576e6f69
Crashed Thread: 0

Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libobjc.A.dylib 0x36c85fc2 0x36c82000 + 16322
1 Foundation 0x35238bb8 0x3522f000 + 39864
2 CoreFoundation 0x354e3d06 0x35454000 + 589062
3 CoreFoundation 0x35477d24 0x35454000 + 146724
4 CoreFoundation 0x354984b0 0x35454000 + 279728
5 Foundation 0x3524c914 0x3522f000 + 121108
6 Foundation 0x3524c8b4 0x3522f000 + 121012
7 Example 0x000027a4 -[ExampleViewController viewDidLoad] (ExampleViewController.m:35)
8 UIKit 0x34a3c124 0x349ff000 + 250148
9 UIKit 0x34a1777a 0x349ff000 + 100218
10 UIKit 0x34b6d288 0x349ff000 + 1499784
11 Example 0x00002538 -[ExampleAppDelegate application:didFinishLaunchingWithOptions:] (ExampleAppDelegate.m:24)
12 UIKit 0x34a17f1c 0x349ff000 + 102172
13 UIKit 0x34a070e6 0x349ff000 + 32998
14 UIKit 0x34a06032 0x349ff000 + 28722
15 UIKit 0x34a05ad0 0x349ff000 + 27344
16 UIKit 0x34a055ea 0x349ff000 + 26090
17 GraphicsServices 0x33f27ef4 0x33f23000 + 20212
18 CoreFoundation 0x354d79c4 0x35454000 + 539076
19 CoreFoundation 0x354d7966 0x35454000 + 538982
20 CoreFoundation 0x354d658c 0x35454000 + 533900
21 CoreFoundation 0x35478036 0x35454000 + 147510
22 CoreFoundation 0x35477efe 0x35454000 + 147198
23 UIKit 0x34a03758 0x349ff000 + 18264
24 UIKit 0x34a0098a 0x349ff000 + 6538
25 Example 0x000024ba main (main.m:14)
26 Example 0x00002478 start + 32