Mac OS X Leopard - ARCAism

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CHAPTER 24 MAC OS X DEVELOPMENT: THE APPLICATION FRAMEWORKS
NOTE For more information on Automator and automation, see Chapter 23.
DotMac Kit
To those of us who’ve been online since the first IP addresses crawled out of the sea, the services
of Apple’s .Mac subscription service are nothing new. E-mail, a home page, and a little space on
a server somewhere are old hat. Still, .Mac manages to remain compelling, not with what it does,
but how.
Normally, publishing things to the Web involves several steps and specialized file transfer
programs. Using the WebDAV standard, the DotMac Kit embeds web services directly into applications.
A user’s .Mac account becomes less like a server and more like an online extension of
their home folder.
Integrating with .Mac is a great way to add value for your users, and is probably the
number-one feature that sets applications designed “for the Mac” apart from applications that
are “Mac compatible.” Fortunately, the DotMac Kit, also known as the .Mac SDK, makes
adding this feature almost as easy as using .Mac itself.
The DotMac Kit breaks all operations into transactions. This means checking credentials,
making sure a user’s account is current, creating a directory, and moving files to and from the
server are all encapsulated as transactions.
Transactions allow you to switch between synchronous and asynchronous modes as needed.
There are a few places where switching modes is handy, but it’s absolutely indispensable for
debugging. There’s also a compatibility interface for the truly lazy, which mimics the methods
used by Cocoa’s NSFileManager class. It doesn’t have the same flexibility as transactions, but for
simple actions or quick prototyping, it’s quite convenient.
Calendar Store
As Address Book does for people, iCal does for events. Aside from the standard questions
(What’s going on? Where? When? Who’s going to be there?), iCal events can include things like
URLs, notes, and alarms: time-sensitive triggers that can do anything from popping up a
reminder, running a script, and sending an e-mail. Using a colorful, easy-to-understand interface,
iCal lets users manage all their calendar-related information in one place, as shown in Figure 24-8.
Again, just like with Address Book, your application can interact with iCal’s data using the
Calendar Store framework. New in Leopard, Calendar Store frees your application (not to mention
your users) from the tedium of dealing with the same information in multiple places.
Calendar Store does more than just accessing, editing, and creating events. It also does the
following:
• Manages Leopard’s system-wide To Do list
• Notifies interested applications of any changes to the calendars
• Provides fast, flexible data-mining services using predicates: high-level, object-oriented
queries used throughout Mac OS X
In fact, it’s better to think of Calendar Store as what it really is: a central database. iCal just
happens to be a conveniently prebundled client. Indeed, Calendar Store is based on CalDAV, an
open networking standard that lets your users connect with server-side collaboration software,
regardless of platform.
It also means your applications calendaring features need no longer bind users to iCal. Any
application can use Calendar Store. In fact, Leopard provides several examples of this kind of
integration. The next time you get a piece of e-mail asking if you’re coming to the party on
Wednesday, try clicking the text and watch iCal add that event, as if your host had sent you an
iCal invitation.