Learn About The Changes And New Features In The iOS 6 Beta 3 Firmware [Changelog]

According to the update blurb,
iOS 6 beta 3 was released under the banner of bugfixes and
improvements, but that’s not to say that there are no new features or
hints as to the features which Apple is introducing in their next
releases.


9to5Mac
has spotted interface changes in some of the default apps. Maps now has
a Settings pages for switching between Miles and Kilometers, toggling
map labels between English names and names in the local languages,
choosing between small or large labels, and setting the volume or
turn-by-turn navigation. The label name support is interesting; perhaps
it means that there will be support for different languages per
localization.

The blog also noticed a change to the bookmarks bar in the iPad’s version of Safari.
The tabs for history, reading list, and bookmarks have been replaced
with icons, and there is now an icon which displays the progress of
syncing lists between Safari browsers.

The change from labels to icons is an interesting move. On one hand,
labels are more intuitive for beginners, because they tell the user what
the button does. Icons are more efficient and usually do not need
localization, although they take more time to learn.

For a more in-depth look at technical changes and known issues in iOS
6, below are the release notes from Apple’s developers portal. These
notes do not outline the features in iOS 6.
While these are mostly checks to ensure that the final version of iOS 6
will be as reliable as Apple products are expected to be, the change
log does contain a notable tidbit or two. One notable change is the
release of iCloud email addresses.


iOS 6 Beta 3 Build 10A5355d Changelog

Introduction
iOS SDK 6.0 provides support for developing iOS apps and includes the
complete set of Xcode tools, compilers, and frameworks for creating apps
for iOS and OS X. These tools include the Xcode IDE and the Instruments
analysis tool among many others.
With this software you can develop apps that run on iPhone, iPad, or
iPod touch running iOS 6. You can also test your apps using the included
iOS Simulator, which supports iOS 6. iOS SDK 6.0 requires a Macintosh computer running OS X 10.7.4 or higher (Lion).
This version of iOS is intended only for installation on devices
registered with Apple’s developer program. Attempting to install this
version of iOS in an unauthorized manner could put your device in an
unusable state.
For more information and additional support resources, visit:

http://developer.apple.com/programs/ios/

Bug Reporting
Please report any bugs not mentioned in the “Notes and Known Issues”
section using the Apple Bug Reporter on the Apple Developer website
(http://developer.apple.com/bugreporter/). Additionally, you may discuss
these issues and iOS SDK 6 in the Apple Developer Forums:
http://devforums.apple.com. You can get more information about iCloud
for Developers at: http://developer.apple.com/icloud
Notes and Known Issues
The following issues relate to using iOS SDK 6.0 to develop code.
Address Book
• When an app is in a fresh privacy state and tries to present a
ABNewPersonViewController, the user cannot dismiss that view controller
properly even if they allow access to contacts. The user must force quit
the app and relaunch.
• Requesting access to contacts:
Users are able to grant or deny access to contact data on a per-app
basis. To request access to contact data, call the
ABAddressBookRequestAccessWithCompletion function after calling the
ABAddressBookCreateWithOptions function. The
ABAddressBookRequestAccessWithCompletion function does not block the app
while the user is being asked to grant or deny access. Until access has
been granted, the ABAddressBookRef object will not contain any contacts
and any attempt to modify contacts fails with a
kABOperationNotPermittedByUserError error. The user is prompted only the
first time access is requested; any subsequent calls to
ABAddressBookCreateWithOptions will use the existing permissions. The
completion handler is called on an arbitrary queue. If the
ABAddressBookRef object is used throughout the app, then all usage must
be dispatched to the same queue to use ABAddressBookRef in a thread-safe
manner.
• Checking access authorization status:
An app can use the authorization status API to check if it can access
contacts, calendars, reminders or photo library. This API is independent
from the the request access API and will not prompt the user to grant
or deny access. With this API an app can adjust the display of its UI
elements that would access the data class. For example, if access to
contacts is authorized or not determined then a UI button to pick a
contact can be displayed.
For Address Book, call the ABAddressBookGetAuthorizationStatus function.
For Event Kit, call the authorizationStatusForEntityType: class method
of EKEventStore. For Assets Library, call the authorizationStatus class
method of ALAssetsLibrary. The meaning of the status values that are
returned is as follows:
Authorization Status Not Determined – The user has not yet made a choice regarding whether this app can access the data class.
Authorization Status Restricted – This app is not authorized to access
the data class. The user cannot change this app’s status, possibly due
to active restrictions such as parental controls being in place.
Authorization Status Denied – The user explicitly denied access to the data class for this app.
Authorization Status Authorized – This app is authorized to access the data class.
Apple TV
• In some cases, the screen may show the wrong resolution. Restart your Apple TV to return it to the correct resolution.
• FIXED: Netflix videos may not resume where you left off.
• FIXED: The History list in the YouTube app gets cleared when you exit and reenter the app.
• Apple TV may be slow to respond while a download is in progress in the background.
• Apple TV may restart while using the Remote app.
• Apple TV may restart when changing the system language.
• Photo Stream does not load when logging in a second time. Restart Apple TV to resolve.
• Music does not play during photo slideshows.
• New Behaviors:
Pick remote speakers in Settings > AirPlay.
Set an onscreen code for AirPlay in Settings > AirPlay.
Save multiple iTunes Store accounts in Settings > iTunes Store.
Press and hold the Select button to rearrange icons on the main menu.
Hide the main menu icons in Settings > General > Parental Controls.
Bonjour
• The NSNetService class and CFNetService APIs do not include P2P
interfaces by default. To browse, register, or resolve services over P2P
interfaces, an app needs to use the Bonjour DNSService*() APIs noted
below.
• Setting the interfaceIndex parameter to kDNSServiceInterfaceIndexAny
in the following API’s will not include P2P interfaces by default. To
include P2P interfaces, you must now set the kDNSServiceFlagsIncludeP2P
flag when using kDNSServiceInterfaceIndexAny or set the interfaceIndex
to kDNSServiceInterfaceIndexP2P. The affected APIs are:
DNSServiceBrowse
DNSServiceRegister
DNSServiceResolve
DNSServiceRegisterRecord
DNSServiceQueryRecord
Dictionary
• There is a known issue with dictionaries when attempting to define a
word in any language other than English or Japanese. When the reference
library is presented, the user is presented with the option to download a
dictionary – that download may not begin. The user can tap outside the
popover on an iPad or tap the “Done” button on the iPhone or iPod touch
in order to dismiss the download request.
Event Kit
• Requesting access to calendars or reminders:
Users are able to grant or deny access to event and reminder data on a
per-app basis. To request access to event and/or reminder data, call the
requestAccessToEntityType:completion: method of EKEventStore. This will
not block the app while the user is being asked to grant or deny
access. Until access has been granted for an entity type, the event
store will not contain any calendars for that entity type, and any
attempt to save data will fail.
The user will only be prompted the first time access is requested; any
subsequent instantiations of EKEventStore will use the existing
permissions. The completion handler is called on an arbitrary queue.
Game Center
• When creating a new Game Center account in-app on the iPad, the
popover for selecting the month for your date of birth shows up with no
content to select.
• The authenticate method of GKLocalPlayer has been removed.
Authentication will automatically commence when the completion handler
is set.
iCloud
• When creating an iCloud account, you can use any email based Apple ID,
or you can use your existing iCloud account. If you had a MobileMe
account that you have not yet moved to iCloud, you must move it first by
visiting http://me.com. Moving to iCloud is only available for a
limited time. Logging into a MobileMe account is not supported in iOS 6.
icloud.com email addresses are now available for iCloud mail users.
Users signing up for new Apple IDs, or enabling Mail on their iCloud
account for the first time, will automatically receive an @icloud.com
email address instead of a me.com email address. iCloud users with
@me.com addresses that have been used with iOS 6 beta 3 will receive an
@icloud.com email address that matches their @me.com address.
icloud.com email cannot be sent from www.icloud.com. Users should use
http://beta.icloud.com at this time if they wish to send email from
their icloud.com address using a web browser.
• Provisioning profiles must be enabled for iCloud in the iOS
Provisioning Portal. To enable a provisioning profile for iCloud,
navigate to the App ID section of the iOS Provisioning Portal and
configure your App ID for iCloud. After enabling the App ID for iCloud,
regenerate your provisioning profiles to enable them for iCloud.
• The setSortDescriptors: method of NSMetadataQuery is not supported.
• In iOS 6, files that are protected via Data Protection cannot be used with iCloud Storage APIs.
• File names are case-insensitive in OS X but case-sensitive in iOS.
This can lead to problems when sharing files between the two platforms
using iCloud. You should take steps on iOS to avoid creating files whose
names differ only by case.
• The behavior of coordinated read operations on iCloud Documents has
changed. On previous iOS releases, when your app performed a coordinated
read operation on a file or package, and the iCloud daemon noticed that
there was a newer version of the item available, the coordinated read
operation blocked until the newer version of the item was downloaded and
written to the disk.
Starting in iOS 6 beta 3, when you start a
coordinated read operation on a file or package for which you already
have a local version, the coordinated read will be granted as soon as
possible, and the new version, if any, will download in the background.
This call will block for downloading reasons only if you do not have any
version of the file available locally.
Additionally, when the file is
conflicted, the iCloud daemon will not wait until it has all the
conflict losers of the file available to make the file available to your
app. It will make the different versions of the conflicted file
available as soon as it can. Your app can use the existing file
coordination and the UIDocument callbacks to be notified when the
conflict losers have been downloaded and are available.
iMessage & FaceTime
• FIXED: The Answer and Decline buttons are missing when receiving calls in landscape orientations.
iTunes
• iTunes 10.6.3 is required for iOS SDK 6.0.
• FIXED: When restoring from an iTunes backup, the device intermittently
shows up as a new device after rebooting. If that happens, set up the
device as a “new device” when prompted to restore for the 2nd time. All
data should have been restored correctly but sync settings including App
arrangement in iTunes are lost.
Maps
• In iOS 6
and later, Map Kit is built on a new infrastructure hosted by Apple.
Earlier iOS releases will continue to use Google’s service.
API compatibility will be maintained (see known issues below).
Maps are now supported in the Simulator.
Map data will continue to evolve—only a limited amount of high resolution satellite imagery is currently available.
• FIXED: If Maps is not running in the background, a “Maps cannot
connect to the internet” error is displayed when it is launched from a
3rd party app.
• FIXED: If Maps has not yet been launched, the current location does not show up when it is launched from a 3rd-party app.
• Routing apps that do not specify a coverage file during development
will always be displayed in the Maps routing search results.
• Testing and debugging of coverage files for routing apps is only
supported during development through the Xcode “Run” workflow. (You can
specify the coverage file for a given Run scheme using the Options pane
of the Run section of the scheme editor.) Apps that are archived and
distributed (outside of the App Store) onto devices will not have access
to the app’s coverage files.
• Maps does not zoom into the current location when launched from a 3rd party app.
Newsstand
• Only simple http downloads will work with Newsstand.
Passbook
• FIXED: An airplane icon appears between the origin and destination for all transit types.
• The “Description” field is now a required field for a Pass. All passes
created without it will fail to validate and will not ingest.
• FIXED: The Passbook database has been reset. You’ll need to add your passes again.
• Passbook in the simulator no longer requires https/ssl when using a webServiceURL when ingesting a pass.
• Unable to show boarding passes on lock screen.
Reminders
• FIXED: There are issues when adding and editing reminders in the Reminders app on iPhone devices:
The Done button is missing when adding a new reminder.
The app crashes when you tap the Edit button to edit a reminder.
Security
• In iOS 5, signing a certificate with an MD5 signature is not
supported. Please ensure that certificates use signature algorithms
based on SHA1 or SHA2.
• In iOS 6, there are improved privacy controls for Calendars, Reminders, Contacts, and Photos.
Users will see access dialogs when an app tries to access any of those
data types. The user can switch access on and off in Settings >
Privacy.
Developers can set a “purpose” string for each class of isolated data.
iOS displays this string to users to help them understand why their data
is being requested. These strings can be added using Xcode’s Project
editor, in the Info tab. The relevant key names begin with the string
“Privacy -”.
There are changes to the Event Kit and Address Book frameworks to help developers with this feature.
Simulator
• The app delete confirmation alert panel takes a while to show up in iOS Simulator.
• FIXED: Tapping the buy button in the view of an SKStoreProductViewController object in iOS Simulator causes the app to crash.
• No privacy alerts are displayed in iOS Simulator for apps that access Photos, Contacts, Calendar and Reminders.
• Downloading in-app purchase hosted content in iOS Simulator is not supported.
• When attempting to play an MP3 sound in the Simulator, you will hear a popping sound instead.
• FIXED: Using the iOS 5.1 SDK with the iPad (Retina) profile will
result in a SpringBoard crash. The iOS 5.1 SDK works with all other
profiles and the iPad (Retina) SDK works with the iOS 6.0 SDK.
• FIXED: Ads of type ADAdTypeMediumRectangle do not appear in iPad Simulator.
Shared Photo Stream
• User must go to Settings > iCloud to ensure that they receive Shared Photo Stream Notifications.
• In order to share a Photo Stream with iOS 6 beta, you must invite
someone using their iCloud email address or they will not receive the
invitation.
• Upgrading from iOS 6 beta 1 to beta 2 will cause your device to re-download all of your Shared Photo Streams.
• The Shared Photo Stream feature is set to OFF when updating from iOS 6
beta 1 to a later release. The default setting should be ON.
• Turning off Shared Photo Streams may leave camera in an unresponsive state, force quitting camera will resolve this issue.
Social
• Weibo shows up in the Settings app only if a Chinese keyboard is enabled.
• The requestAccessToAccountsWithType:withCompletionHandler: method of
ACAccountStore is now deprecated. To access user accounts, please use
the requestAccessToAccountsWithType:options:completion: method. In the
options parameter of this new method, pass nil to access Twitter and
Weibo accounts. To access Facebook accounts, pass a dictionary with the
following keys (which are documented in ACAccountStore.h):
ACFacebookAppIdKey
ACFacebookPermissionsKey
ACFacebookPermissionGroupKey
• You should no longer add this dictionary to your app’s Info.plist file, as was required in beta 1.
SpringBoard
• FIXED: After restoring a device in iTunes or performing an “Erase All
Contents and Settings”, the current wallpaper may not appear until the
device is rebooted once.
Status Bar
• It is now possible to set status bar tint parameters in your app’s
Info.plist file. You might do this to ensure that the status bar color
matches the navigation bar color of your app during startup. To set the
status bar tint, add the UIStatusBarTintParameters key to your
Info.plist file. The value of this key is a dictionary with the
appropriate values describing the navigation bar your app has at startup
time. Inside the dictionary should be the UINavigationBar key, whose
value is also a dictionary. That dictionary contains the initial
navigation bar’s style (with the Style key) and whether it’s translucent
(with the Translucent key). If your navigation bar uses them, you can
also specify its tint color (with the TintColor key), or the name of its
custom background image (with the BackgroundImage key).
UIKit
• In iOS 5.1, the UISplitViewController class adopts the sliding
presentation style when presenting the left view (previously only seen
in Mail). This style is used when presentation is initiated either by
the existing bar button item provided by the delegate methods or by a
swipe gesture within the right view. No additional API adoption is
required to obtain this behavior, and all existing API, including that
of the UIPopoverController instance provided by the delegate, will
continue to work as before. If the gesture would be insupportable in
your app, setting the presentsWithGesture property of your split view
controller to NO disables the gesture. However, disabling the gesture is
discouraged because its use preserves a consistent user experience
across all apps.
• FIXED: In iOS 6, changes have been introduced so that you no longer
need to set a delegate and implement a method for Single-Finger and
Single-Tap gesture recognizers, in an effort to make them work well with
the UIControl objects.
• In iOS 6 and later, the UIWebView class paints its contents asynchronously.
• FIXED: Developers trying out Auto Layout with UIScrollView objects
might notice jitters in the scroll indicators on devices with Retina
displays.
• Autorotation is changing in iOS 6. In iOS 6, the
shouldAutorotateToInterfaceOrientation: method of UIViewController is
deprecated. In its place, you should use the
supportedInterfaceOrientations and shouldAutorotate methods.
More responsibility is moving to the app and the app delegate. Now, iOS
containers (such as UINavigationController) do not consult their
children to determine whether they should autorotate. By default, an app
and a view controller’s supported interface orientations are set to
UIInterfaceOrientationMaskAll for the iPad idiom and
UIInterfaceOrientationMaskAllButUpsideDown for the iPhone idiom.
A view controller’s supported interface orientations can change over
time. Even an app’s supported interface orientations can change over
time. The system asks both the topmost full screen view controller
(typically the root view controller) for its supported interface
orientations whenever the device rotates or whenever a view controller
is presented with the full screen modal presentation style. Moreover the
supported orientations are retrieved only if this view controller
returns YES from its shouldAutorotate method. The system intersects the
view controller’s supported orientations with the app’s supported
orientations (as determined by the Info.plist file or the app delegate’s
application:supportedInterfaceOrientationsForWindow: method) to
determine whether to rotate.
The system determines if an orientation is supported by intersecting the
value returned by the app’s supportedInterfaceOrientationsForWindow:
method with the value returned by the supportedInterfaceOrientations
method of the topmost fullscreen controller.
The setStatusBarOrientation:animated: method is not deprecated outright.
However it now works only if the supportedInterfaceOrientations method
of the topmost full screen view controller returns 0. This puts the
responsibility of ensuring that the status bar orientation is consistent
into the hands of the caller.
For compatibility, view controllers that still implement the
shouldAutorotateToInterfaceOrientation: method do not get the new
autorotation behaviors. (In other words, they do not fall back to using
the app, app delegate, or Info.plist file to determine the supported
orientations.) Instead, the shouldAutorotateToInterfaceOrientation:
method used to synthesize the information that would be returned by the
supportedInterfaceOrientations method.
• FIXED: In certain situations, the Auto Layout system might not engage
automatically for a view. To workaround this problem, override the
requiresConstraintBasedLayout class method in your view and return YES
from your implementation.
• The willRotateToInterfaceOrientation:duration:,
willAnimateRotationToInterfaceOrientation:duration:, and
didRotateFromInterfaceOrientation: methods are no longer called on any
view controller that makes a full screen presentation over itself—for
example, by calling presentViewController:animated:completion:.
You should make sure that your apps are not using these methods to
manage the layout of any subviews. Instead, they should use the view
controller’s viewWillLayoutSubviews method and adjust the layout using
the view’s bounds rectangle.
• In iOS 6, the viewWillUnload and viewDidUnload methods of
UIViewController are now deprecated. If you were using these methods to
release data, use the didReceiveMemoryWarning method instead. You can
also use this method to release references to the view controller’s view
if it is not being used. You would need to test that the view is not in
a window before doing this.
• FIXED: Calling any of the attributed string drawing methods without
specifying a value for the NSFontAttributeName attribute is likely to
throw an exception. The workaround is to set a value for the
NSFontAttributeName key before drawing or sizing an NSAttributedString
object.
• Setting values for the shadowOffset or shadowColor properties of a
UILabel object, whose attributedText property contains a valid
attributed string, is unsupported. Use the NSShadowAttributeName
attribute of the attributed string to set the shadow instead.
• Due to compatibility concerns, the NSBaselineOffsetAttributeName attribute is no longer supported in iOS 6.
• The NSTextAlignmentNatural value is unsupported and will throw an
exception when used with the textAlignment property of UILabel or
supplied as the alignment parameter to the
drawInRect:withFont:lineBreakMode:alignment: method of NSString.
• The setContentStretch: method of UIView has been deprecated in this
beta release. To achieve the same effect, use the
resizableImageWithCapInsets: method of UIImage and display the image
with a UIImageView.
• The resizableImageWithCapInsets: method of UIImage effectively resizes
images by tiling. As a performance optimization, it uses stretching
rather than tiling when the user would not be able to tell the
difference, like when a single column or row is being stretched. But in
certain circumstances, one might want to actually stretch some region of
an image. In iOS 6, the resizableImageWithCapInsets:resizingMode:
method allows the caller to specify a tiling or stretching resizing
mode.
• The UICollectionViewLayout class has changed:
The class now supports the customization of the animations created
during rotation. The names of methods for customizing insert and delete
animations have also changed so that the same hooks can be used for
rotations as well as for insertions and deletions.
The class has changed some method names. Specifically, decoration views
are no longer referred to by “reuse identifier” but rather by “element
kind.” Apps that are using decoration views will need to modify their
code and rebuild to accommodate this.
• FIXED: In iOS 6, a bug was fixed where UIWebView.isLoading was set to
NO before the main frame finished loading. Now, UIWebView.isLoading is
set to NO when the main frame is done loading.
• The bottom edge of a UILabel view is now different from its
baseline.Previously, auto layout was interpreting the bottom of a
UILabel to be the same as its baseline. While convenient in many cases,
it caused problems if you wanted to place the top edge of one label
against the bottom edge of another. In such a scenario, the bottom label
would overlap the top one, and descenders from the top label could
crash into ascenders from the bottom label. Now, auto layout interprets
UILayoutAttributeBottom as the bottom of the text box (presuming the
label is not bigger than its intrinsic content size), and
UILayoutAttributeBaseline as the baseline of the text. If you have
already created code for laying out labels according to the bottom or
center point, your text will move around a little and you will need to
adjust your constraints.
• Apps with table views in their nib or storyboard files, and that were
built using previous versions of iOS 6 beta, will require a clean build
with beta 3 and newer.
• Here are some notes regarding auto layout support for UIScrollView:
In general, auto layout considers the top, left, bottom, and right edges
of a view to be the visible edges. That is, if you pin a view to the
left edge of its superview, you’re really pinning it to the minimum
x-value of the superview’s bounds. Changing the bounds origin of the
superview does not change the position of the view.
The UIScrollView class scrolls its content by changing the origin of its
bounds. To make this work with auto layout, the meaning of the top,
left, bottom, and right edges within a scroll view now mean the edges of
its content view.
The constraints on the subviews of the scroll view must result in a size
to fill, which is then interpreted as the content size of the scroll
view. (This should not be confused with the intrinsicContentSize method
used for auto layout.) To size the scroll view’s frame with auto layout,
constraints must either be explicit regarding the width and height of
the scroll view or the edges of the scroll view must be tied to views
outside of its subtree.
Note that you can make a subview of the scroll view appear to float (not
scroll) over the other scrolling content by creating constraints
between the view and a view outside the scroll view’s subtree, such as
the scroll view’s superview.
Here are some examples of how to configure the scroll view:
Mixed approach:
1. Position and size your scroll view with constraints external to the
scroll view—that is, the translatesAutoresizingMaskIntoConstraints
property is set to NO.
2. Create a plain UIView content view for your scroll view that will be
the size that you want your content to have. Make it a subview of the
scroll view but let it continue to translate the autoresizing mask into
constraints:
3. UIView *contentView = [[UIView alloc]
4. initWithFrame:CGRectMake(0,0,contentWidth,contentHeight)];
5. [scrollView addSubview:contentView];
6. // DON’T change contentView’s translatesAutoresizingMaskIntoConstraints,
7. // which defaults to YES;
8.
9. Set the content size of the scroll view to match the size of the content view:
10. [scrollView setContentSize:CGMakeSize(contentWidth,contentHeight)];
11.
12. Create the views you want to put inside the content view and
configure their constraints so as to position them within the content
view.Alternatively, you can create a view subtree to go in the scroll
view, set up your constraints, and call the systemLayoutSizeFittingSize:
method (with the UILayoutFittingCompressedSize option) to find the size
you want to use for your content view’s size and the contentSize
property of the scroll view.
Pure auto layout approach:
1. In this case translatesAutoresizingMaskIntoConstraints must be set to NO on all views involved.
2. Position and size your scroll view with constraints external to the scroll view.
3. Use constraints to lay out the subviews within the scroll view, being
sure that the constraints tie to all four edges of the scroll view and
do not rely on the scroll view to get their size.A simple example would
be a large image view, which has an intrinsic content size derived from
the size of the image. In the viewDidLoad method of your view
controller, you would include code like the following:
4. UIScrollView *scrollView = [[UIScrollView alloc] init];
5. UIImageView *imageView = [[UIImageView alloc] init];
6. [imageView setImage:[UIImage imageNamed:"MyReallyBigImage"]];
7. [self.view addSubview:scrollView];
8. [scrollView addSubview:imageView];
9.
10. scrollView.translatesAutoresizingMaskIntoConstraints = NO;
11. imageView.translatesAutoresizingMaskIntoConstraints = NO;
12.
13. NSDictionary *viewsDictionary = NSDictionaryOfVariableBindings(scrollView,imageView);
14. [self.view addConstraints:[NSLayoutConstraint
constraintsWithVisualFormat:@"H:|[scrollView]|” options:0 metrics: 0
viewsDictionary:viewsDictionary]];
15. [self.view addConstraints:[NSLayoutConstraint
constraintsWithVisualFormat:@"V:|[scrollView]|” options:0 metrics: 0
viewsDictionary:viewsDictionary]];
16. [scrollView addConstraints:[NSLayoutConstraint
constraintsWithVisualFormat:@"H:|[imageView]|” options:0 metrics: 0
viewsDictionary:viewsDictionary]];
17. [scrollView addConstraints:[NSLayoutConstraint
constraintsWithVisualFormat:@"V:|[imageView]|” options:0 metrics: 0
viewsDictionary:viewsDictionary]];
18. 
This would give you a scroll view that resized as the view
controller’s view resized (such as on device rotation), and the image
view would be a scrolling subview. You don’t have to set the content
size of the scroll view.
Safari & WebKit
• WebKit on iOS now supports the requestAnimationFrame and
cancelAnimationFrame methods in JavaScript, as described here
http://www.w3.org/TR/animation-timing/.
Note that because the specification is still at the Working Draft state,
these methods have the webkit prefix, so they are
window.webkitRequestAnimationFrame, window.webkitCancelAnimationFrame.
• The default app cache quota has been increased from 5MB to 25MB.
• The JPEG subsampling threshold was increased from 2 MP (megapixels) to
5 MP on all supported hardware except iPhone 3GS and iPod touch (4th
gen).
• Support has been added for tags in web
forms. Users can upload existing photos and videos from their photo
library or take a picture or video using the camera. Previously this
form control was always disabled.
• With Safari 6.0 on OS X, developers can now use the Web Inspector (web
development tool) with attached iOS devices and iOS Simulator.
Developers can use the Web Inspector to debug Safari and the UIWebView
class in their own apps built and run from Xcode. This replaces the
Debug Console banner in Safari.
• In iOS 6 and later, web data (SQL Web Storage and LocalStorage) from a
UIWebView object can be stored in a directory that will be backed up.
To enable backing up this data, set the WebKitStoreWebDataForBackup key
to YES in your app’s user defaults. This should be done only if your app
relies on web content data that cannot be reloaded. If your UIWebView
object opens links to arbitrary web content, this key should be set to
NO. Toggling the value of this key will not preserve existing web view
data.
• In iOS 6 and later, Safari no longer registers for the common feed:
RSS/ATOM scheme. Apps that can view those types of feeds are encouraged
to register for that URL scheme.
• WebKit no longer always creates hardware-accelerated layers for
elements with the -webkit-transform: preserve-3d option. Authors should
stop using this option as a way to get hardware acceleration.
• Experimental CSS3 Flexbox support will be disabled. Please switch from
using -webkit-flexbox and -webkit-inline-flexbox to -webkit-box and
-webkit-inline-box.
• As of iOS 6, embedded YouTube URLs in the form of
https://www.youtube.com/watch?v=oHg5SJYRHA0 will no longer work. These
URLs are for viewing the video on the YouTube site, not for embedding in
web pages. Instead, the format that should be used is described in
https://developers.google.com/youtube/player_parameters.
• In iOS 6, the keyboardDisplayRequiresUserAction property was added to
the UIWebView class. The property defaults to YES, which means that
calling focus() on a form element will not bring up the keyboard. By
changing the property to NO, a JavaScript call to focus() on a form
element will focus the element and automatically bring up the keyboard.
• As of iOS 6, calling focus() on a form element in a web app will focus the element.

Are you waiting for the full release of iOS 6, or did you get your hands on the most recent beta?