In the sandboxed world of iOS development sharing data between
applications can prove difficult Since iOS developers can’t share data
directly through the file system, they need to find alternate
solutions for their applications. Some common solutions include:
-
UIDocumentInteractionController
-
UIActivityViewController
-
Shared Keychain Access
-
Custom URL Scheme
-
Web Service
-
iCloud API
UIDocumentInteractionController:
Allows the user to open a document in any other application that
registers as being able to handle a particular document Uniform Type
Identifier (UTI).The UIDocumentInteractionController has been used in the past as a
means of opening a document in other applications on the device, for
example, opening email attachments from the Mail app.
Unfortunately, the UIDocumentInteractionController‘s UI displays only
six applications.You cannot guarantee that your application will appear in the list.
While the UIDocumentInteractionController has not been deprecated, the
UIActivityViewController provides a more flexible replacement as of iOS 6.0.
Availability: iOS 3.2+
Pros:
- Allows sharing of common data types with a wide array of
applications.
Cons:
-
Allows control of the type of data sent to the UIDocumentInteractionController, but not the destinations.
-
Requires additional user interaction.
-
Limited number of data destinations may cause your application not to display in the list.
UIActivityViewController:
Allows the user to perform a number of actions with an array of data.
For example they may print, email, copy, post to social media, or open
in another application.You may create your own UIActivity subclasses to provide custom
services to the user.
Availability: iOS 6.0+
Pros:
-
Great for sharing common data types with a wide array of applications and social media.
-
Can supply an array of items for application to an activity. Objects should conform to UIActivityItemSource protocol.
-
Has the ability to set excluded activity types.
-
Paging UI allows for more data destinations than UIDocumentInteractionController.
Cons:
-
You must define a custom activity type to restrict “Open In…” destinations of common data types.
-
Requires additional user interaction.
Shared Keychain Access:
Allows you to securely store data to a shared keychain that other
applications that are part of a suite of applications can access.All applications that share keychain access must use the same app ID
prefix.For an example of shared keychain access in action. See Apple’s
GenericKeychain sample code.
Availability: iOS 3.0+
Pros:
- Secure access to data.
Cons:
-
You can only share data between applications that share a common app ID prefix.
-
The Keychain API on the iOS Simulator comes from OS X, which has different API than that of the iOS device.
Custom URL Scheme:
Allows data to pass between applications using simple URLs.
Availability: iOS 3.0+
Pros:
- No network connection required.
- Great for small amounts of data that you can easily encode into an escaped, legal URL.
Cons:
- You must encode data into an escaped legal URL.
Note: base64 encoding has seen common use turning serializable data into a string value. However, base64 strings may include characters that are invalid for use in URLs. You might consider using base64url. See Base 64 Encoding with URL and Filename Safe Alphabet for more information.
iCloud API:
Everybody knows about what is iCloud,Pros and Cons so no more
explanation for that.But One might ask how it is possible to share data between
applications inside a single device there are some workarounds to
achieve that.
It’s possible because the identifier which is used for iCloud is
different from bundle identifier so it’s possible to share
images,videos and other documents.To know more see the discussion on this topic
Web Service:
Sync data through third party (e.g. Dropbox) or custom built web
service.
Availability: iOS 2.0+
Pros:
- Useful for sharing and otherwise distributing large amounts of data.
Cons:
- Requires a network connection.
- Web service implementation overhead.