Thursday, December 12, 2013
Abstract of
iCloud
Apple introduced iCloud in iOS5 as a service to allow
applications to store data on Apple’s servers and have it synchronized across
all devices used by the same person (via their Apple ID). It also has a backup
component. This document describes how to use some of the iCloud APIs provided
by Apple to store and retrieve data from their servers, with C# samples for
storing small key-value data pairs and for storing documents. It also discusses
how iCloud Backup can influence the design of your application. The iCloud
storage API in iOS5 allow applications to save user documents & application
specific data to a central location and access those items from all the user’s
devices. iCloud helps you store your photos, music, apps, documents, calendars
and more. It’s an easiest way to manage your content. Apple has built iCloud
functionality directly into many of their apps and iOS5. When you take a photo
from your iPhone, it can automatically synchronize with iCloud, and be pushed
to your iPad and Mac.
You can stop worrying about keeping all of your devices in
sync once they are all linked to your iCloud account. Once you connect your
device to the internet via a wired or Wi-Fi connection, all of your files will
be automatically synchronized. The Backup feature allows you to store your
personal data, along with music apps and books purchased from iTunes. You can
restore all of your data directly to your device from iCloud, or move it to any
new devices you buy. Apple has opened up development to third-party developers,
which means that there will eventually be iCloud compatible apps for Windows
aside those developed by Apple. Eventually iCloud development could spread to
other platforms including Linux, Android, and BlackBerry. If you switch back
and forth between a Windows PC and your Mac, it will not be long before you can
keep both of them in sync with iCloud. You get 5GB of backup space for free,
and there will likely be different pricing tiers based on how much data you
want to store in iCloud. For $24.99 a year you get the Scan and Match feature,
which scans your iTunes music library and adds any songs that are available in
the iTunes library to your iCloud account. It does not matter if you purchased
the songs from iTunes, from another music store, or ripped the CDs. All songs
added to your iCloud account using the Scan and Match feature will be at
256kbps (DRM-free AAC files) regardless of the quality of your original track.
There is a limit of 25,000 songs, but iTunes purchases do not count against
that limit.
iCloud Backup
While backing up to iCloud isn’t a feature that is directly
accessed by developers, the way you design your application can affect the user
experience. Apple provides iOS Data Storage Guidelines for developers to follow
in their iOS applications. The most important consideration is whether your app
stores large files that are not user-generated (for example, a magazine reader
application that stores hundred-plus megabytes of content per issue). Apple
prefers that you do not store this sort of data where it will be backed-up to
iCloud and unnecessarily fill the user’s iCloud quota. Applications that store
large amounts of data like this should either store it in one of the user
directories that is not backed-up (eg. Caches or tmp) or use
NSFileManager.SetSkipBackupAttribute to apply a flag to those files so that
iCloud ignores them during backup operations. This article introduced the new
iCloud feature included in iOS 5. It examined the steps required to configure
your project to use iCloud and then provided examples of how to implement
iCloud features.
The key-value storage example demonstrated how iCloud can be
used to store a small amount of data similar to the way NSUserPreferences are
stored. The UIDocument example showed how more complex data can be stored and
synchronized across multiple devices via iCloud. Finally it included a brief
discussion on how the addition of iCloud Backup should influence your
application design.
Photostream:
Photo Stream is a service supplied with the basic iCloud
service which allows users to store the most recent 1,000 photos on the iCloud
servers up to 30 days free of charge. When a photo is taken on a device with
Photo Stream enabled, it is automatically uploaded to the iCloud servers; from
there, it is automatically pushed to the rest of the user's registered devices.
The service is also integrated with Apple TV, allowing users to view their
recent photos wirelessly on their HDTV. With Photo Stream, you can take a photo
on one iOS device and it automatically appears on all your other devices,
including your Mac or PC. Import new pictures to your computer from a digital
camera, and iCloud sends copies over Wi-Fi to your iPhone, iPad, and iPod
touch. You can even view recent photos on your big-screen TV via Apple TV.
There’s no syncing, no email attachments, no file transfers. Your pictures are
just there — on whichever device you happen to have handy.
Take a photo on an iOS device. Or import a photo from your
digital camera to your computer. iCloud automatically pushes a copy of that
photo over any available Wi-Fi or Ethernet connection to the Photos app on your
iOS devices, iPhoto or Aperture on your Mac, and the Pictures Library on your
PC. You can even view your Photo Stream album on your Apple TV. So you can show
off your shots to friends and family from whichever device you’re using at the
time.1000 of your latest photos. With you all the time.iCloud manages your
Photo Stream efficiently so you don’t run out of storage space on your iPhone,
iPad, or iPod touch. If you have Photo Stream enabled on your iOS device, every
single photo you take appears in a special Photo Stream album that holds your
last 1000 photos.
You can delete any photos you don’t want from the Photo
Stream.1 To touch up a photo or keep a favorite shot permanently, simply save
it to your Camera Roll. iCloud stores new photos for 30 days, so you have
plenty of time to connect your iOS device to Wi-Fi and make sure you always
have your most recent shots handy.1000 photos on your devices: New photos
appear on your iPhone, iPad, or iPod touch in a rolling collection of your last
1000 photos.Save your best shots: If you take a photo you really love and want
to make sure it stays on your iPhone, iPad, or iPod touch, you can save it from
your Photo Stream to your Camera Roll.All your photos on your Mac or PC: Your
computer automatically keeps all the photos that come through your Photo
Stream.Master photo library. On your Mac or PC.
Keeping a complete set of your photos on your Mac is as
simple as turning on Photo Stream in iPhoto or Aperture. Every new photo you
take appears in a Photo Stream album just as it does on your iPhone, iPad, and
iPod touch. But since your Mac has more storage than your iOS device, it
automatically imports every picture from your Photo Stream into your photo
library so you can edit, delete, and share the ones you want. Want to get the
photos you’ve taken on your point-and-shoot or DSLR camera into your Photo
Stream to view on all your other devices? The photos you import to your library
from a camera or SD card are automatically uploaded to your Photo Stream. If
you have a PC, you can auto-import and upload pictures, too. Just turn on Photo
Stream, grab a camera, and start shooting.Make your photos a big deal with
Apple TV.With Photo Stream and Apple TV, you can view your recent photos on
your HDTV for some truly entertaining reality television.2 So you can, say,
take pictures during your daughter’s softball game, then watch a photo
play-by-play with the family gathered around the big-screen TV.
References
http://www.apple.com/iphone/features/
http://www.quora.com/Whats-the-difference-between-the-cloud-cloud-computing-and-iCloud
http://www.quora.com/Whats-the-difference-between-the-cloud-cloud-computing-and-iCloud
