iCloud Document Storage with UIDocument - Beginning iOS Cloud and Database Development - page 57

Chapter 5
iCloud Document Storage
with UIDocument
In this chapter you will learn the fundamentals of adding iCloud Document Storage to your applications.
I start by explaining what the iCloud Document storage is and how it has been integrated into core
technologies for you to leverage. In discussing these technologies I show you the two different ways
that you can take your application to iCloud by using UIDocument and Core Data.
Next we dive into detail on both of these technologies. Using our test app from the previous chapter
we will add a new section that uses UIDocument at the local level. I then modify the app to show you
how you can move those local documents to iCloud.
Because Core Data is such a complex technology I highly recommend using other materials
completely devoted to it. We will add a third section to our application that utilizes a Core Data
backend. And just like we did for UIDocument , we take Core Data and move it to the iCloud.
iCloud Document Storage
iCloud Document Storage utilizes a Document Service that exists on all devices. This service
orchestrates the persistence of data from a special directory on the device and the iCloud server. The
service sends your application messages, alerting you to changes through the iCloud Storage API.
I know it may sound too simple to be true, but it actually is that simple. The engineers at Apple
have taken care of all of the server side code for you. You don't have to worry about load balancing,
replication, disaster recovery, or anything else that you would normally need to think about when
implementing a server technology. So, with that said let's go a little deeper.
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