There are pretty much two types of timers with two styles of setting the callback. There is the scheduled timer which adds the timer to a default run loop which will start the timer automatically, and there is the standard timer which must be added to an NSRunLoop (which I won’t cover here). Both types have a variation which can be initialized with an NSInvocation class, which is really a fancier way of setting the callback (target selector). So let’s start with the most basic example of how you would initialize, and use NSTimer.

// Assume this is in a controller class, or somewhere equally useful
 
- (NSTimer)createTimer {
    // Create a managed timer (don't need to add to the run loop!)
    self.timer = [NSTimer scheduledTimerWithTimeInterval:0.5
        target:self selector:@selector(targetMethod:)
        userInfo:nil repeats:YES];
 
    return self.timer;
}
 
- (void)targetMethod:(NSTimer*)timer {
    NSLog(@"targetMethod called!");
}

Now that example will fire the timer as soon as you call createTimer, and trigger the targetMethod until you quit the application or call [self.timer invalidate];. It should be noted that with this method the target HAS to take the timer as an argument.

What if you KNOW you won’t need a repeating timer though? There must be an easier way. Well, there is. Every NSObject class has the method performSelector:withObject:afterDelay: which makes life even easier.

More complete examples on NSTimer can be found in the reference library.

Functional and concurrent languages were pretty much all the rage in 2009. I’ve been looking a little at languages, and Clojure seems pretty cool, as does Erlang. These languages make my brain hurt seeing as I’ve really only ever worked with C syntax languages, but it could be a good learning experience.

2. Learn to use neural networks

I had some experience with some basic AI this year, and did some work with genetic algorithms, but I don’t feel like it really gave me much more insight into developing intelligent software.

3. 3D with OGRE 1.7

OGRE is the rendering engine to watch next year with the announcement of iPhone support, MIT license, and the release of Torchlight, . Not sure what my actual plans would be, but I’d like to actually build something this time around. Even if it’s just a simple tech demo.

4. Finish an iPhone app?

Yeah, I’ve started a lot, and finished pretty much nothing this year. With 3 or 4 apps already on the go, I think I should probably get around to finishing something soon.

Turns out I won despite some other brilliant entries. My secret sauce was the use of nested ternary operators, and pretty much makes the code unreadable. I’m posting the example in case anyone is interested in running it and seeing if they can improve/learn from it. Might also be worth noting that you should turn php notices off, and give $n an unsigned int value (for best results).

The code:
<?$a=str_repeat;for($t=$n+1;$t--;)echo$a(' ',$t?$t-1:$n-1).($t?$t==$n?"^":"/".$a('*',($p+=1*2)-1)."\\":'|')."\n";

This morning I read an article that pissed me off. It pissed me off because there were parts I agreed with, and it pissed me off because so much of the community agreed with the parts I didn’t. It was also frustrating because I couldn’t quite express just why it frustrated me so much, but now I can. The article made some big statements about app developers, and even bigger assumptions about what consumers want.

I happen to have written some cocoa, and even a few web apps in my time, and frankly, there are downsides on either side of the fence. It’s no doubt that the web has caught up to desktop applications in a pretty big way in the last 3-4 years. There was a time I would have never considered paying for a web application, let alone think of it as replacing a desktop app. Apps like Google docs, and a few productivity apps have proven me wrong.

There are still some good reasons for native apps though, and the sales figures on Apples app store speak for themselves. I think consumers might actually know what they want.

1. Convenience

On the app store, you can buy an application in seconds, and usually for the price of a coffee. On the web, it might mean a sign-up process, and usually involves digging out a credit card or paypal password. There is effort required for something that should be serving you. Pricing is also a part of this. I’d rather pay $1.99 for an app a might only try for a few minutes, than spend $20+ a year for subscription I might have to remember to cancel in a few months. I’d rather throw a dice than make a commitment.

2. Experience

The other aspect is user experience. If I am using iPhone apps, I expect each application to behave in a certain way, and have a certain look. If I see a table view in 5 different apps, I know they are going to behave in the same way. I’m willing to pay a few bucks for that. On the web, you are at the mercy of what the developer thinks UI should behave like. Performance is also a pretty big part of this. I don’t have to wait for UI images, CSS, or javascript to load before I can start using most native apps. It’s usually just there when I want it. I know arguments can be made for local caching, and optimization, but that’s assuming a lot about the skills of the developer, and generally comes as an after thought.

3. Ownership

This is probably my lamest argument of all, but it’s hard to deny it’s importance. I like the feeling that an app is downloaded to my device all tucked away in the filesystem with my preferences in a (mostly) secure location. With a web app, I’m at the mercy of the developer deciding his app isn’t paying the server bills, the network going down, and my personal information being who knows where.

These aren’t significant issues.

I really believe in the web as a platform, but I also think that the line between native apps and “the cloud” is starting to fade. As a developer, the biggest difference is the tools and the delivery. I happen to think that building a native app and maintaining it without the worry of infrastructure would be pretty nice for a change. It can also be a joy to use proprietary tools when they are well thought out, and work when you need them to. The app store is necessary, and so is the web. It’s a great time to be developing for either. Take some time to think about which type of app your customers would want before you begin the bashing.

I think it’s going to super useful for people collaborating. I love that Wave can bridge the gap between IM, and email. I hate having to dig through IM conversations to get info, and I also hate missing important info because I didn’t have my email client open. So, people who say Wave doesn’t solve a problem don’t spent a lot of time on the internet.

There’s so many reasons why Wave won’t be replacing email though. The type of work I do probably puts me in the top 1% of people who spend ridiculous amounts of time on the internet, and even I could live without Wave. But gosh darn, it’s pretty neat. It’s going to come down to how many people I know that use it, and how good the mobile app will be. If nothing else, Wave is a pretty big step forward, and pushes a lot of the bounds of what  even the most web 2.0 people thought was possible.

About 5 months ago now, I launched my little social networking experiment called you-vs-me.com. The idea was that people could create discussions, and vote on things they prefer. Using that data, I would work hard at calculating compatibility. It seemed simple to create, and it looked as though it would be a web app that would get people talking.

What went right

I was right about a few things. It was a good idea (for the most part). The design looked inviting, and I got compliments that the app didn’t look like it was made by one guy in his free time. The app was fairly simple to use, and the user interactions seemed meaningful. I was also right that it got people talking. The Twitter integration brought me the majority of my traffic, and even got me some media attention. The first month had me thinking that my idea was taking off as planned.

What went wrong

There are a lot of things I didn’t do right. One of the worst things I did was removing the invite codes too early. I found that it was way easier to market you-vs-me as a closed beta app that was invite only. The other things I did wrong was not using a service like Facebook connect, or OpenID, and not utilizing Twitter to its full potential. I spent too much time thinking about how my app would scale if it got popular, than trying to help it get popular. I think that’s probably a common mistake when a developer sees some early success, but it’s so much easier to just pay a little more for hosting (which I did too).

Unfortunately, even if I had done all of the above right, I think that the concept of the site was just too limiting. I had not given people enough reason to sign in. The app could have been better executed as a powerful API, and Facebook app. But even then, the compatibility algorithm I had created was weak at best, and quite buggy early on. My plan was to use my smoke and mirrors parlor trick compatibility calculation until I could make something compelling. What could have been the focal point of the app just wasn’t powerful enough to convince anyone.

Conclusion

I can feel pretty good that I made a quality application that gave me some great programming, business, and marketing experience. I’m still looking for the next great idea, and right now I’m still not sure what direction to go. Whether I am going towards mobile, web, or some sort of business service as my next side project, I think I learned some valuable lessons.

Seems pretty amazing to me that I was able to port the library from C++ to python in a handful of hours on the weekend, but I guess that shows why so many smart people are using python. Anyway, the library is nothing amazing, but it is very powerful and simple. I still need to learn a few things about python, and make things a little more flexible, but I have put the library on github under MIT license for anyone interested in using it.

Genetix.py

Twitter has more or less taken over for the events in my life, and the pictures that I take, yet I’d still like an outlet to share things I learn, and my journey in the field of technology. As burnt out as I feel from time to time, I know I love thinking about how to design software, and getting excited about my next big project. Point is I probably won’t be changing careers any time soon, so I might as well be a voice in the community, and have a place to share my thoughts.