Objective-C Fundamentals

316 APPENDIX C Alternatives to Objective-C
Figure C.2 Spot the
difference: the Facebook web
application on the left and
the Facebook native
application. The web
application lacks certain
features, such as access to
the camera and photo library.
Developers can create Web 2.0 applications which look and behave just like the applications
built into iPhone, and which can seamlessly access iPhone’s services, including making a
phone call, sending an email and displaying a location in Google Maps.
“iPhone to Support Third-Party Web 2.0 Applications,”
(www.apple.com/pr/library/2007/06/11iphone.html)
From this comment, it’s hard to imagine why you’d learn Objective-C—a technology
that finds little use outside of Apple-based platforms. It appears that reusable skills
such as HTML, CSS, and JavaScript are a better approach. An iPhone web application
can be as simple as a website rendered by the iPhone’s Safari web browser. By altering
layout, CSS styling, and so on, a web application can achieve fairly good parity with the
look and feel of native applications, as shown in figure C.2.
One advantage of web-based applications is their ability to automatically and instantaneously
update to a newer version. When you update the source code hosted on your
web server, all users are immediately upgraded; in fact, the user has no option to decide
if or when they upgrade. On the negative side, however, the iTunes App Store provides a
simple, economic model to allow you to monetize and charge for your applications.
Finding a way to monetize web applications, which can’t be hosted in the iTunes App
Store, is left as an exercise for the developer.
C.3.1
HTML5, CSS3, and other modern standards
Web-based applications require a connection to the internet so their source code can be
downloaded from the web server. This appears to rule out their use in scenarios such as
airplane flights or subway travel, where radio transmitting devices are either prohibited or