Objective-C Fundamentals

The iPhone SDK: Safari
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C.3.2
have potentially patchy (or no) coverage. Mobile Safari offers support for an HTML5 feature
called the Offline Application Cache that offers a solution to this limitation. It allows
a manifest file to be written that outlines the files (HTML, JavaScript, CSS, and image files)
a web application requires. Safari downloads all files listed in the manifest and ensures
they’re available while offline. Provided your web application doesn’t depend on serverside
functionality, your application will happily run while the device is offline.
The Offline Application Cache is only
one of many advanced technologies
implemented by Safari. Other examples
include extensions to CSS to support
rounded edges, shadows, transforms, animations,
and transitions; rich canvas and
SVG support for vector-based client-side
drawing; and even APIs to store data on
the client side.
Figure C.3 Examples from http://cubiq.org, the
blog of Matteo Spinelli, demonstrating the use of
Mobile Safari is a world-class mobile
CSS3 transitions, animations, transformations,
browser designed to enable the development
of serious web-based applications. approach the behavior and look and feel of native
JavaScript, and HTML to build web-based UIs that
iPhone applications
As evidence of some of the powerful UI
elements that can be crafted with pure
HTML, CSS, and JavaScript, take a look at the various demos available on Matteo
Spinelli’s blog at http:// c u b i q . o rAs g . seen in figure C.3, many of the UI elements
seen in Apple and third-party iOS applications can be replicated easily in a webbased
environment.
An intrinsic advantage of developing using standardized web-based technologies is
their inherent ability to support more than one platform. With tweaks to your HTML
and CSS, it’s often possible to develop a web application that provides fairly good
native look and feel across a wide range of mobile platforms, such as Microsoft’s Windows
Mobile (now called Windows Phone), Research In Motion’s Blackberry, Palm’s
WebOS, and Nokia’s various platforms. With Mobile Safari leading the charge, most if
not all of these alternative platforms have equally rich web browser support. This isn’t
to say you’re left with a mediocre application that can’t access device-specific functionality.
An iPhone web application has access to a number of iPhone-specific device
capabilities and features.
iPhone OS integration
iPhone integration for web applications covers not only access to hardware features
such as the GPS, accelerometer, and compass, but also aspects that help make web
applications feel more like a natural part of the operating system. For example, by
adding the following line of HTML to your main page, you can enable a static image to
be displayed as a splash screen while your web application HTML and JavaScript
source code is downloaded, parsed, and rendered behind the splash screen: .