In a move foreshadowed by the Newton Message Pad fifteen years ago, Apple's new iPad jettisons the conventional shared file system and introduces a new, streamlined convention for working with document files that ordinary users should find much more understandable.
Outside of savvy computer users, the idea of opening a file by searching through hierarchical paths in the file system is a bit of a mystery. Add in the concept of local and cloud file servers and things really get confusing.
Apple has already taken some steps to hide complexity in the file system in Mac OS X; Spotlight search was supposed to make a file's location almost irrelevant, while apps such as iTunes, iPhoto, and Photo Booth now present their databases of content in media folders within the open file panel rather that forcing users to slog through the underlying file system.
The Finder, iTunes and iPhoto also allow users to wirelessly share content between different systems via Bonjour-discovered file shares that pop up automatically whenever another system sharing files is sensed on the network.
The iPhone similarly abstracts away the file system entirely; there is no concept of opening or saving files, just a media library of Photos and file attachments that stay connected to their mailbox items. But the iPhone currently isn't designed to do much more than view files.
iPad's new document sharing model
With the iPad, Apple demonstrated new multitouch versions of desktop-class iWorks apps with user interfaces that need to open and save documents. There's still no file system browser with open and save panels. Instead, each app displays the files it knows about at launch for the user to navigate through directly.
An iPad developer has revealed to AppleInsider how this new mechanism works, without also requiring that users learn about the complexity of the underlying file system. Rather than iPad apps saving their documents into a wide open file system, apps on iPad save all their documents within their own installation directory. Delete the app and you'll clean out all of its related files. This is how the iPhone OS already works.
Additionally, iPad apps can now specify that their documents be shared wirelessly. With that configuration, the iPad will make available each apps' documents, allowing the user to wirelessly mount their iPad via WiFi and simply drag and drop files back and forth between it and their desktop computer.
On the desktop system, the iPad will show up as a share containing a documents folder for each app that enables sharing. For example, a user with iWork apps will be able to wirelessly connect to their iPad as if it were a directly connected drive, and simply drag spreadsheet, presentation, or word processing files between their local system and the mobile device as desired.
Documents copied to the app's shared folder will be graphically presented by the app when it launches, sparing users from having to figure out where to look for their document files and avoiding any need to sort through different kinds of documents. The document listing also presents each file as a large preview akin to Quick View on the Mac OS X desktop.
And iPad app's documents can be presented in any way that makes sense, depending on how many and what kind of documents the individual iPad app uses. Apple demonstrated its Work apps scrolling through a quick list of documents, while its iBooks app presents its various digital books as titles in a virtual bookshelf.
Just like the iPhone, the iPad will sync some apps' documents via either iTunes or MobileMe, including photos, music, movies, TV shows, contacts, calendars, and bookmarks.