Information Technology Reference
In-Depth Information
Creating an App ID
An App ID isn't just a string; it tags the app's bundle and controls access to various special services. A unique ID
defines a single app. An ID that includes a wildcard defines a suite of apps.
Unique IDs can be configured to give an app access to Apple's live services: in-app purchasing, push no-
tification, and game center.
Unique IDs also can be linked to specific hardware accessories.
Keychain access in an iOS device gives all apps with a shared wildcard ID the same access privileges, so
they can share passwords and other securely stored data.
If you don't need to support special features or shared security, use a wildcard ID for convenience. You
can use the same ID for all your apps.
CAUTION
Don't use a wildcard ID if your apps access the Keychain, unless you explicitly want to enable password sharing. If
you create two apps with a common wildcard ID that store passwords, the passwords are shared automatically.
This may not be the behavior you want.
The process as a whole sounds more complex than it really is. In previous versions of Xcode, you were forced to
create the App ID manually. In later versions, including Xcode 4, the process has been automated and simpli-
fied, so now it mostly “just works.”
To create a valid ID, follow these steps:
Creating a suite ID
1.
On the Portal, select App IDs.
2.
Click the New App ID button at the top right, and fill in the fields as shown in Figure 11.11.
Description:
Type a string. This description is for your reference only, but it does appear elsewhere on
the portal and in Xcode, so it's a good idea to keep it short, such as MyApp, AppOne, GameOne, and so
on.
Bundle Seed ID:
Leave this set to Generate New.
Bundle Identifier (App ID Suffix):
You can either type
*
as a wildcard or
com.domainname.*
.
Use the latter if your app will be exchanging data with other apps through URL schemes, UTIs, and other
more advanced options. Use a single
*
for a simple self-contained app.
CROSS-REFERENCE
For a very short introduction to URL schemes, UTIs, and so on, see Chapter 17.
3.
Click the Submit button when you're finished.
The Portal immediately creates your new suite/wildcard ID and takes you back to the App ID page. The new
ID appears at the bottom of the page. The 10-letter string defines the prefix.
