Tag Archives: iphone

Social plugin for Phonegap 2.6 and up

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In my search to have the iOS 6 default social sharing plugin, I landed up at this page. While everything seems right for this plugin, I somehow faced some problems in the UX. Thought would look a little deeper into it and found that this plugin relies upon the old plugin architecture of Phonegap. It still works, but then if it does not, you know know why.
Now to implement social sharing in my project, I have done a quick round of update to the plugin. Its working in my phonegap version 2.6. And that should work on Phonegap 3 as well, as the new plugin implementation has not changed after version 2.0.
Here is the github link for the new plugin.
While currently this plugin only shares the link and the message, you have to send a third parameter as an empty string for the image parameter. I will do the code cleanup and fix as I get some time to look into it. For the time being, its ready to use in new Phonegap versions.

Happy coding :)

Cordova(Phonegap), jQueryMobile and making a popup

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This may seem obvious to make a pop-up with jQuerymobile with its popup API, but its a little more than just calling the api.
The problem is closing the popup. When working in a single page application in jQuerymobile and phonegap, the closing of the popup will take you to different jQueryMobile pages depending upon your setup.
The solution is to make the popup ready to be open just at the current page and while closing it should not make the application go to different pages. The trick is to while initialising the popup widget, initialise it with “{history: false}”, and thats all.
Here is a popup created with jQueryMobile API.


	

		
My PopUp

	

	

		
Title

		
		
		
		Save
		Cancel

Here is the javascript code to initialise the widget and open it.

//making a popup which will not take you back to the previous page.
$('#popupDialog').popup({history: false});//awesomeness
$('#popupDialog').popup('open');

Happy coding :)

Settings Check for Apple Push Notification

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While developing an iOS application with Push Notification, there might be a time, one comes across the following error message.

- no valid 'aps-environment' entitlement string found for application

Well, that means the APN (Apple Push Notification) server is denying to register your application. This situation arises when the signing certificate for the application differs from the one you generated for Push Notification.

The fix is to select the proper certificate in the settings for the project.
codeSigningCert

Happy coding.

Cordova (Phonegap) , alert message.

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This might seem, very easy task. But then while making a customisable alert message, one need to think as to how to do it. While working on Cordova(phonegap), one can easily assume and which is true is the javascript alert script.

alert("Hello!");

The javascript alert will work. Then we do not have a customisation option except for the message. The solution Cordova provides is a function with the name as alert. The syntax is as below.

navigator.notification.alert(message, alertCallback, [title], [buttonName]);

In the very basic form, where one need to have a specific title, message and button name, the code I use is

navigator.notification.alert("My message", undefined,"My Alert", "ok");

Thats the simplest kind and if one need more generic, wrap the whole thing inside one of your own custom function as example below.

function showAlertWithTitle(title,message){
	navigator.notification.alert(message, undefined,title, "ok");
}

Hope coding.

iOS notifications from developer's view

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Notifications in iOS devices such as iPhone and iPad are a way to tell the user about some important thing has happened. From a users perspective it is just a message reminding thing.
For a developer, one must note the difference between the type of notifications. Well, to be at its simplest form, there re two kinds of notifications. One is local notification and one is push notification (think this as server is telling the iOS device to show the notification).
Well, why should I bother about these two as a developer ?! That might be the question if you are doing the notification programming in iOS for the first time. The answer is, iOS gives very certain instructions as to what and how to do the notification implementation.
Here is the official link to the Apple documentation.

There are only three types of UX for either of the notification (local or push). They are
1. Displaying an alert message
2. Badge the application icon
3. Play a sound

The settings to control these notification types are located in the global settings menu of iOS. Remember it, the settings of all the applications, which use notifications are at one place in all iOS devices and that is the “settings” menu.
Well, another subtle but important option is “notification center”. Its the place, where all the notifications from all the applications reside. The settings, whether to keep the “notification” in “notification center” or not is also inside the global “settings” menu. Being a developer, the good thing about Apple and for that matter the iOS is, one does not code for adding settings item for notifications. It is done automatically for you by the OS (Operating System). All this magic happens, when you as a developer, makes a “certificate” for the application in Apple developer’s portal for the application saying “this application used notification”. Simple and elegant.

The major difference from developer’s point, between local notification and push notification is local notification is scheduled. That means, we can not show a notification if certain things happen in the application. Once application goes to background, we lost power as a developer to do anything at all with that application. So local notifications can only be scheduled for a normal application (for music streaming applications we do get a little more control). If at all we have to notify the user on certain data change, we have to fall back to push notifications. This one is pushed by Apple Push Notification server. Though, there are third party services which can push data, but all of the data push to an users device route through Apple Push Notification server.
The last thing to note is Push notifications are created on the server and pushed to the device, at max, upon tapping the notification, the underlying application can be brought to foreground and thats all one can do as a developer.

Tips for phonegap developers :
1. There are two different official plugins (one for local and one push notification), but then these plugins are not always up to date or might not support your version of the phonegap(cordova), do some reading before you settle down with the plugins.
2. The third party service providers (for push notification) might have their own plugins (a lot of do have), its better to use their plugins if you are developing upon their infrastructure.

Tip for push notification :
Make sure you are creating proper certificate with “push notification service” enabled at “Apple developer portal” and then using a profile on XCode which uses that certificate.

Some push notification servers are
1. http://www.pushwoosh.com
2. http://www.xtify.com
3. https://pushwizard.com

Would like to know if anything I am missing here, I am putting things here as I am doing hands-on with this iOS “notifications” for the first time.

iOS5 with ARC ( Automatic Reference Counting )

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With iOS5 comes the most important feature for me as a developer, Automatic Reference Counting.
This is may not feel a large announcement from an user’s perspective but as a developer, this is the feature. Well, what does that mean and how it affects me as an iOS application developer? This means no retain and release, yeeeaaaahhooooo. If you are developing for iOS devices till now, the pain of maintaining the reference count of an object is always there till it goes to the appstore. With the ARC, one can now forget those. In other words we can say finally garbage collection is here with iOS5, though its not that from a technical perspective, but from a developers perspective its kind of that.
Here is the official description about all the features of iOS5.
Whatever the announcement is for others, but for a developer it is the most significant release of the iOS till now.

Lua : My experience with it.

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Well, on my journey with mobile development, I picked up Lua for sometime. I am quite impressed with its simplicity and power. If you do not know, Corona SDK provides Lua scripting language to build applications for mobile devices. The popular Angrybirds game utilises the power of Lua.
Basically its a simple language with very minimum number of key words and language syntaxes. Anyone familiar with javascript or actionscript can start jumping into it and be productive from day one. There are variants of the installer for Mac and Windows. Some what I feel Windows installer is the best and has got its own IDE, which is on top of popular SciTE IDE.
There is a complete 2D game engine / framework for Lua named Love. With that one can instantly start creating Lua games. As Lua is simple, so as Love is. But then one gets a whole lot of goodies out of a framework. I would say a must try for any game developer.
There is a nice framework for iPhone, which uses Lua and its called WAX. This also fits Lua’s philosophy as to keep the framework simple and easy. The best part is, once you start coding in WAX, you do not have to think about memory management, which is very important and sometimes most time consuming act, while developing application with ObjectiveC.
Now that I have seen Lua’s power and simplicity, I will try that out more and more and post updates about my experiments. Here are some Lua related links for you to get used to
1. Users, tutorials and more
2. Love : 2D game engine
3. WAX : iOS development framework
4. 2D Engine A 2D game engine (I Have not tried yet)
5. Luxinia 3D game engine (I have not tried yet)
6. Lua Forge Projects, tutorials and more
7. Baja Engine A game engine (I have not tried yet)

With that I think I also have to pick up some engines and start playing with it. Overall, Lua feels just perfect as its simplicity and power. Its portable and lightweight. After all its Opensource and Free.

My second iphone game

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CatchThemAllV0.1.0

Just finished my second iphone game. While I have not tested it on device yet!!

My first iphone game was taking the accelerometer into game play and this game is all about multi-touch. While it is quite straight forward to play, but it holds the ability of being engaging and addictive.

The game play is to choose the color which is displayed maximum times on screen. There are only 5 colours, but then one has to count the number of times. There is a simple counter runs to show how much time one is spending in a particular question. If the counter reaches 1000, the question changes to the next question and the player looses one point. The interesting part of the same is, each of the colours is assigned a different touch input. That means, if the player has to choose a particular colour, he/she may have to touch with 3 fingers, similarly there are 2 finger touch, 4 finger touch etc are available.
The game play is going to be interesting if you are trying out in device, on the simulator, its a waste and boring thing.
Hope, I will test it soon with a real device and come up with my first experience with it.

Code is hosted at Github and the direct location is here.

Happy Gaming :)

Making random numbers in ObjectiveC, the quick and dirty way.

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This is another part of my iphone development experience, where I really feel the pain over and again. So putting up my quick way to do get a random number. There are a lot of methods regarding the random number generation in objectiveC and there are even third party attempts to get the best random number possible.
The three most obvious functions are rand(),random() and arc4random(). While a lot can be heard around of not getting a random number by the first two functions, the last options is better. At least I get decent random numbers with it.
Now to get a random number between 2 points, the code would be

//random number between 0 and 5 not 5, till 4
int i=arc4random()%5;
//random number between 10 and 15 not 15, till 14
int j=10 + arc4random()%5;

Hope that makes my next random number creation search leads me to look at this post.
Happy coding :)

Dealing with Touch Events, the Sparrow way.

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This is specifically caught me, when I am coming from other object oriented technology. May be because of those environments are all single touch based. And I never have worked in multi-touch based application.
While working in Sparrow-framework, there is a nice event called “SP_EVENT_TYPE_TOUCH” . This is basically used if we want to use the touch based interaction in our game. Once we add an handler to it, the general expectation is it will just fire up once per touch/tap. But actually it will fire up 2 times as we have 2 different events, “touchesBegan” and “touchesEnded” for each touch interaction in the main cocoa/objectiveC framework. And the good news is Sparrow-framework does a nice job of encapsulating the internals of all those two events and gives us one event to deal with, that is “SP_EVENT_TYPE_TOUCH”.
Well, but the catch is getting confused with the event handler code. Lets dive in here.

[self addEventListener:@selector(onUserTouch:) 
	atObject:self forType:SP_EVENT_TYPE_TOUCH];

Now the handler code will look as below

- (void)onUserTouch:(SPTouchEvent*)event
{
        NSLog(@"onUserTouch");
}

When run, this code will generate log messages two times for a single touch! Thats for the reason we discussed earlier. Well, the fix is on the handler. We have to deal the events inside if-else where we will check, whether its single or multi touch as below.

- (void)onUserTouch:(SPTouchEvent*)event
{
        NSLog(@"onUserTouch");
        NSArray *touches = [[event touchesWithTarget:self 
                       andPhase:SPTouchPhaseBegan] allObjects];
	if (touches.count==1) {
		NSLog(@"1 fingure touch ");
               //Do the custom code here for single touch events
	}else if (touches.count==2) {
		NSLog(@"2 fingure touch ");
	}
}

For only single touch the syntax is even smaller

- (void)onUserTouch:(SPTouchEvent*)event
 {
     SPTouch *touch = [[event touchesWithTarget:self 
                 andPhase:SPTouchPhaseBegan] anyObject];
     if (touch)
     {
         SPPoint *touchPosition = [touch locationInSpace:self];
         NSLog(@"Touched position (%f, %f)", 
              touchPosition.x, touchPosition.y);
     }
 }

The only difference being, while handling single touches we can directly use “anyObject” as the last parameter and that will give us a single event and for multi-touch environments we have to use “allObjects” as the last parameter. But all this will happen inside the event handler, which will by default fire up twice.
One has to get the “touch” or “touches” inside the event handler and then process the code according to it. Directly the handler will fire up twice and that must not confuse as to, whats happening around!

Happy coding :)