About Incorporating iCloud into Your App

Describes how to incorporate iCloud into your app.

At a Glance

iCloud is all about content, so your integration effort focuses on the model layer of your app. Because instances of your app running on a user’s other devices can change the local app instance’s data model, you design your app to handle such changes. You might also need to modify the user interface for presenting iCloud-based files and data.

In one important case, Cocoa adopts iCloud for you: A document-based app for OS X v10.8 or later requires very little iCloud adoption work, thanks to the capabilities of the NSDocument class.

There are many different ways you can use iCloud storage, and a variety of technologies available to access it. This document introduces all the iCloud storage APIs and offers guidance in how to design your app in the context of iCloud.

iCloud Supports User Workflows

Adopting iCloud key-value and document storage in your app lets your users begin a workflow on one device and finish it on another.

Say you provide a podcast app. A commuter subscribes to a podcast on his iPhone and listens to the first 20 minutes on his way to work. At the office, he launches your app on his iPad. The episode automatically downloads and the play head advances to the point he was listening to.

For a drawing app, an architect creates some sketches on her iPad while visiting a client. On returning to her studio, she launches your app on her iMac. All the new sketches are already there, waiting to be opened and worked on.

To store state information for the podcast app in iCloud, you’d use iCloud key-value storage. To store the architectural drawings in iCloud, you’d use iCloud document storage.

Relevant Chapter: iCloud Fundamentals (Key-Value and Document Storage)

Many Kinds of iCloud Storage

There are four iCloud storage APIs to choose from. To pick the right one (or combination) for your app, make sure you understand the purpose and capabilities of each. The iCloud storage types are:

Key-value storage for discrete values, such as preferences, settings, and simple app state.

iCloud document storage for user-visible file-based information such as word-processing documents, drawings, and complex app state.

Core Data storage for shoebox-style apps and server-based, multidevice database solutions for structured content. iCloud Core Data storage is built on iCloud document storage and employs the same iCloud APIs.

CloudKit storage for managing structured data in iCloud yourself and for sharing data among all of your users.

Relevant Chapters: Designing for Key-Value Data in iCloud , Designing for Documents in iCloud , Designing for Core Data in iCloud , Testing and Debugging (Key-Value and Document Storage) , Designing for CloudKit

About Incorporating iCloud into Your App

At a Glance

See Also