Iphone – PhoneGap vs. Titanium

I registered with stackoverflow just for the purpose of commenting on the mostly voted answer on top. The bad thing is stackoverflow does not allow new members to post comments. So I have to make this comment more look like an answer.

Rory Blyth's answer contains some valid points about the two javascript mobile frameworks. However, his key points are incorrect. The truth is that Titanium and PhoneGap are more similar than different. They both expose mobile phone functions through a set of javascript APIs, and the application's logic (html, css, javascript) runs inside a native WebView control.

1. PhoneGap is not just a native wrapper of a web app. Through the PhoneGap javascript APIs, the "web app" has access to the mobile phone functions such as Geolocation, Accelerometer Camera, Contacts, Database, File system, etc. Basically any function that the mobile phone SDK provides can be "bridged" to the javascript world. On the other hand, a normal web app that runs on the mobile web browser does not have access to most of these functions (security being the primary reason). Therefore, a PhoneGap app is more of a mobile app than a web app. You can certainly use PhoneGap to wrap a web app that does not use any PhoneGap APIs at all, but that is not what PhoneGap was created for.

2. Titanium does NOT compile your html, css or javascript code into "native bits". They are packaged as resources to the executable bundle, much like an embedded image file. When the application runs, these resources are loaded into a UIWebView control and run there (as javascript, not native bits, of course). There is no such thing as a javascript-to-native-code (or to-objective-c) compiler. This is done the same way in PhoneGap as well. From architectural standpoint, these two frameworks are very similar.

Now, are they any different? Yes. First, Titanium appears to be more feature rich than PhoneGap by bridging more mobile phone functions to javascript. Most noticeably, PhoneGap does not expose many (if any) native UI components to javascript. Titanium, on the other hand, has a comprehensive UI APIs that can be called in javascript to create and control all kinds of native UI controls. Utilizaing these UI APIs, a Titanium app can look more "native" than a PhoneGap app. Second, PhoneGap supports more mobile phone platforms than Titanium does. PhoneGap APIs are more generic and can be used on different platforms such as iPhone, Android, Blackberry, Symbian, etc. Titanium is primarily targeting iPhone and Android at least for now. Some of its APIs are platform specific (like the iPhone UI APIs). The use of these APIs will reduce the cross-platform capability of your application.

So, if your concern for your app is to make it more "native" looking, Titanium is a better choice. If you want to be able to "port" your app to another platform more easily, PhoneGap will be better.

Updated 8/13/2010: Link to a Titanium employee's answer to Mickey's question.

Updated 12/04/2010: I decided to give this post an annual review to keep its information current. Many things have changes in a year that made some of the information in the initial post outdated.

The biggest change came from Titanium. Earlier this year, Appcelerator released Titanium 1.0, which departed drastically from its previous versions from the architectural standpoint. In 1.0, the UIWebView control is no longer in use. Instead, you call Titanium APIs for any UI functions. This change means a couple things:

1. Your app UI becomes completely native. There is no more web UI in your app since the native Titanium APIs take over control of all your UI needs. Titanium deserves a lot of credit by pioneering on the "Cross-Platform Native UI" frontier. It gives programmers who prefer the look and feel of native UI but dislike the official programming language an alternative.

2. You won't be able to use HTML or CSS in your app, as the web view is gone. (Note: you can still create web view in Titanium. But there are few Titanium features that you can take advantage of in the web view.)Titanium Q&A: What happened to HTML & CSS?

3. You won't be able to use popular JS libraries such as JQuery that assume the existence of an DOM object. You continue to use JavaScript as your coding language. But that is pretty much the only web technology you can utilize if you come to Titanium 1.0 as a web programmer.

Titanium video: What is new in Titanium 1.0.

Now, does Titanium 1.0 compile your JavaScript into "native bits"? No. Appcelerator finally came clean on this issue with this developer blog:Titanium Guides Project: JS Environment. We programmers are more genuine people than those in the Marketing department, aren't we? :-)

Move on to PhoneGap. There are not many new things to say about PhoneGap. My perception is that PhoneGap development was not very active until IBM jumped on board later this year. Some people even argued that IBM is contributing more code to PhoneGap than Nitobi is. That being true or not, it is good to know that PhoneGap is being active developed.

PhoneGap continues to base itself on web technologies, namely HTML, CSS and JavaScript. It does not look like PhoneGap has any plan to bridge native UI features to JavaScript as Titanium is doing. While Web UI still lags behind native UI on performance and native look and feel, such gap is being rapidly closed. There are two trends in web technologies that ensure bright feature to mobile web UI in terms of performance:

1. JavaScript engine moving from an interpreter to a virtual machine. JavaScript is JIT compiled into native code for faster execution. Safari JS engine: SquirrelFish Extreme

2. Web page rendering moving from relying on CPU to using GPU acceleration. Graphic intensive tasks such as page transition and 3D animation become a lot smoother with the help of hardware acceleration. GPU Accelerated Compositing in Chrome

Such improvements that are originated from desktop browsers are being delivered to mobile browsers quickly. In fact, since iOS 3.2 and Android 2.0, the mobile web view control has become much more performing and HTML5 friendly. The future of mobile web is so promising that it has attracted a big kid to town: JQuery has recently announced its mobile web framework. With JQuery Mobile providing UI gadgets, and PhoneGap providing phone features, they two combined creates a perfect mobile web platform in my opinion.

I should also mention Sencha Touch as another mobile web UI gadget framework. Sencha Touch version 1.0 was recently released under a dual licensing model that includes GPLv3. Sencha Touch works well with PhoneGap just as JQuery Mobile does.

If you are a GWT programmer(like me), you may want to check out GWT Mobile, an open source project for creating mobile web apps with GWT. It includes a PhoneGap GWT wrapper that enables the use of PhoneGap in GWT.

Like any which-tool-or-platform-or-language-or-framework-or-whatever question, it should really come down to what you want.

Forget all the if-you-want-to-develop-for-this-platform-then-you-have-to-pay-your-dues advice. If you're interested in learning Objective-C, Xcode, and associated Apple bits, then goferit. I did. It's been fun, but my interest was in developing iPhone apps. Learning a new language, framework, and IDE was just a bonus (I like this stuff). It was also necessary when I started.

I've been working with MonoTouch since it was released, and I love it. I prefer C# to Objective-C, and I like having access to the subset of the .Net (Mono) framework that MonoTouch provides. There are certain things that are simply easier to do with .Net than Cocoa (string manipulation, date manipulation, anything XML, etc.).

I also like not having to deal with reference-counting anymore. I was spoiled by years of not having to keep track of resources at that level. I don't mind having to clean up after myself, but I don't want to have to manually do something that every other modern dev platform I've used does for me automatically. Plus, even for seasoned Objective-C devs, reference-counting isn't a no-brainer. Scroll through OS X's console output sometime to see how many apps crash due to memory-management issues (I know - this can happen with basically any app, but it's far easier to make the mistakes that lead to this situation when you get overworked devs involved whose attention spans have been destroyed by twelve hours of if this and if that and else this and else that and blah blah blah).

I still use Objective-C/Xcode - I've really learned to like Apple's tools. I honestly feel they're awkward and a bit arcane, but still fun.

But... then I also like this:

public string SomeString { get; set; }

To do the same thing with Objective-C (on the iPhone, anyway) requires that you declare a local variable to back the property, write the property declaration, and then use the "synthesize" directive to have the property generated for you (depending on what property attributes you specify, you might have a property that wraps getters and setters that take care of reference-counting for you - overall, this is a time-saver, but the C# Way is the clear winner here).

That's just one example of how MonoTouch can make your life easier, especially if you're used to .Net/Java/Python/other languages that don't require that you get your fingers dirty with memory-mangement (unless you want to).

As far as iPhone-ness is concerned, aside from brining part of .Net to the iPhone world, the MonoTouch namespace maps to CocoaTouch, so if you're confused about, say, the MonoTouch UIViewController, you can just hop over to Apple's docs on the UIViewController. MonoTouch .Net-izes CocoaTouch, but it's close enough that you're unlikely to hit a wall (that wouldn't have also hit if you were using Xcode/Objective-C). It's slick.

Titanium is different. Since they're trying (trying) to create an abstraction layer that lets you write the same app for multiple platforms, you're going to deal with the usual drawbacks: Totally different APIs, loss of flexibility (the same could be said of MonoTouch, but not remotely to the same degree), and basically having to learn a whole new platform (which is what you're trying to avoid by getting around Xcode/Objective-C/CocoaTouch, right?).

I also hate JavaScript, so I'm going to be biased against Titanium. But even if that weren't the case - even if I could use a language I do like - the APIs don't tickle my fancy. Or my anything.

Regardless of the dev tools you choose, you will end up having to learn something about CocoaTouch. Whether it's Xcode/Objective-C, MonoTouch, or Titanium, something is going to break or go all wonky on you, and you're eventually going to have to refer to CocoaTouch documentation.

If I were giving a talk on iPhone development (which I have, and which I will be doing again), and if I were to discuss alternatives to Apple's dev tools (which I will), I would still strongly encourage devs to at least work through a few basic iPhone apps using the native tools. It's going to make you a better developer for the platform - period. And you can use this beginning phase to determine if you even want to use anything other than the free Apple-supplied bits. You might not. I've been using MonoTouch because it pleases me - not because it's necessary.

So, to summarize a few basic criteria:

• Preference (language/frameworks)

• Devices (do you care about non-iPhone platforms or think you might someday?)

• Comfort (if you like and know C# MUCH better than Objective-C, there's no reason not to go with MonoTouch)

And don't listen to the naysayers unless they've actually used the tech they're talking about. For example, I've read about Titanium, but I'm not experienced with it - I just know that I don't want anything to do with it on account of my preferences. That doesn't make it "bad" - just something I don't want in my life.

The Objective-C crowd can be impressively zealous. While there are plenty of open-minded devs in it, there are so, so, so many who think Objective-C and Cocoa and blah blah blah are THE last dev tools devkind will ever need.

Ignore them.

If you're worried about support, here's some stuff to consider:

• Apple is likely to remain current, as they're the ones making this junk.

• MonoTouch is likely to remain current - the Mono peeps have done an amazing job keep up with Microsoft, and I see no reason why they won't do the same with Apple. I'm blown away by what they do. And despite MonoTouch having been released, like, five minutes ago, they already have an update out for iPhone 3.1 stuff. They're serious about this, and I think they're magic. They're the Keebler Elves of the dev world. They sit in their secret layers and crank out stuff everybody (ok - not everybody) likes, but that nobody else would even attempt to do.

• Titanium is either going to become an awkward unified API for writing apps for multiple platforms that is entirely its own thing, or it's going to become more and more splintered as the capabilities of different platforms diverge. Yeah, that's a bunch of typical armchair nerdly future-gazing... I should have prefaced this bullet item with "It's my opinion that..." If only there were a way to go back and change it.

I'll shut up now.

Go with what you like. MonoTouch is a "safe" alternative to Apple's stuff. I'm afraid Titanium is going to go down the same old oops-this-super-high-level-platform-abstraction-layer-stuff-doesn't-really-work road that so many other technologies have. But if you're doing something simple, there's no harm in giving it a shot, especially considering that it's free during the beta period.

Aright.

Really shutting up now... I hope this helps.