FBKVOController Class Reference
| Inherits from | NSObject |
|---|---|
| Declared in | FBKVOController.h |
Overview
FBKVOController adds support for handling key-value changes with blocks and custom actions, as well as the NSKeyValueObserving callback. Notification will never message a deallocated observer. Observer removal never throws exceptions, and observers are removed implicitely on controller deallocation. FBKVOController is also thread safe. When used in a concurrent environment, it protects observers from possible ressurection and avoids ensuing crash. By default, the controller maintains a strong reference to objects observed.
+ controllerWithObserver:
Creates and returns an initialized KVO controller instance.
+ (instancetype)controllerWithObserver:(id)observerParameters
observer |
The object notified on key-value change. |
|---|
Return Value
The initialized KVO controller instance.
Declared In
FBKVOController.h
– initWithObserver:retainObserved:
The designated initializer.
- (instancetype)initWithObserver:(id)observer retainObserved:(BOOL)retainObservedParameters
observer |
The object notified on key-value change. The specified observer must support weak references. |
|---|---|
retainObserved |
Flag indicating whether observed objects should be retained. |
Return Value
The initialized KVO controller instance.
Discussion
Use retainObserved = NO when a strong reference between controller and observee would create a retain loop. When not retaining observees, special care must be taken to remove observation info prior to observee dealloc.
Declared In
FBKVOController.h
– initWithObserver:
Convenience initializer.
- (instancetype)initWithObserver:(id)observerParameters
observer |
The object notified on key-value change. The specified observer must support weak references. |
|---|
Return Value
The initialized KVO controller instance.
Discussion
By default, KVO controller retains objects observed.
Declared In
FBKVOController.h
observer
The observer notified on key-value change. Specified on initialization.
@property (atomic, weak, readonly) id observerDeclared In
FBKVOController.h
– observe:keyPath:options:block:
Registers observer for key-value change notification.
- (void)observe:(id)object keyPath:(NSString *)keyPath options:(NSKeyValueObservingOptions)options block:(FBKVONotificationBlock)blockParameters
object |
The object to observe. |
|---|---|
keyPath |
The key path to observe. |
options |
The NSKeyValueObservingOptions to use for observation. |
block |
The block to execute on notification. |
Discussion
On key-value change, the specified block is called. Inorder to avoid retain loops, the block must avoid referencing the KVO controller or an owner thereof. Observing an already observed object key path or nil results in no operation.
Declared In
FBKVOController.h
– observe:keyPath:options:action:
Registers observer for key-value change notification.
- (void)observe:(id)object keyPath:(NSString *)keyPath options:(NSKeyValueObservingOptions)options action:(SEL)actionParameters
object |
The object to observe. |
|---|---|
keyPath |
The key path to observe. |
options |
The NSKeyValueObservingOptions to use for observation. |
action |
The observer selector called on key-value change. |
Discussion
On key-value change, the observer’s action selector is called. The selector provided should take the form of -propertyDidChange, -propertyDidChange: or -propertyDidChange:object:, where optional parameters delivered will be KVO change dictionary and object observed. Observing nil or observing an already observed object’s key path results in no operation.
Declared In
FBKVOController.h
– observe:keyPath:options:context:
Registers observer for key-value change notification.
- (void)observe:(id)object keyPath:(NSString *)keyPath options:(NSKeyValueObservingOptions)options context:(void *)contextParameters
object |
The object to observe. |
|---|---|
keyPath |
The key path to observe. |
options |
The NSKeyValueObservingOptions to use for observation. |
context |
The context specified. |
Discussion
On key-value change, the observer’s -observeValueForKeyPath:ofObject:change:context: method is called. Observing an already observed object key path or nil results in no operation.
Declared In
FBKVOController.h
– observe:keyPaths:options:block:
Registers observer for key-value change notification.
- (void)observe:(id)object keyPaths:(NSArray *)keyPaths options:(NSKeyValueObservingOptions)options block:(FBKVONotificationBlock)blockParameters
object |
The object to observe. |
|---|---|
keyPaths |
The key paths to observe. |
options |
The NSKeyValueObservingOptions to use for observation. |
block |
The block to execute on notification. |
Discussion
On key-value change, the specified block is called. Inorder to avoid retain loops, the block must avoid referencing the KVO controller or an owner thereof. Observing an already observed object key path or nil results in no operation.
Declared In
FBKVOController.h
– observe:keyPaths:options:action:
Registers observer for key-value change notification.
- (void)observe:(id)object keyPaths:(NSArray *)keyPaths options:(NSKeyValueObservingOptions)options action:(SEL)actionParameters
object |
The object to observe. |
|---|---|
keyPaths |
The key paths to observe. |
options |
The NSKeyValueObservingOptions to use for observation. |
action |
The observer selector called on key-value change. |
Discussion
On key-value change, the observer’s action selector is called. The selector provided should take the form of -propertyDidChange, -propertyDidChange: or -propertyDidChange:object:, where optional parameters delivered will be KVO change dictionary and object observed. Observing nil or observing an already observed object’s key path results in no operation.
Declared In
FBKVOController.h
– observe:keyPaths:options:context:
Registers observer for key-value change notification.
- (void)observe:(id)object keyPaths:(NSArray *)keyPaths options:(NSKeyValueObservingOptions)options context:(void *)contextParameters
object |
The object to observe. |
|---|---|
keyPaths |
The key paths to observe. |
options |
The NSKeyValueObservingOptions to use for observation. |
context |
The context specified. |
Discussion
On key-value change, the observer’s -observeValueForKeyPath:ofObject:change:context: method is called. Observing an already observed object key path or nil results in no operation.
Declared In
FBKVOController.h
– unobserve:keyPath:
Unobserve object key path.
- (void)unobserve:(id)object keyPath:(NSString *)keyPathParameters
object |
The object to unobserve. |
|---|---|
keyPath |
The key path to observe. |
Discussion
If not observing object key path, or unobserving nil, this method results in no operation.
Declared In
FBKVOController.h
– unobserve:
Unobserve all object key paths.
- (void)unobserve:(id)objectParameters
object |
The object to unobserve. |
|---|
Discussion
If not observing object, or unobserving nil, this method results in no operation.
Declared In
FBKVOController.h
– unobserveAll
Unobserve all objects.
- (void)unobserveAllDiscussion
If not observing any objects, this method results in no operation.
Declared In
FBKVOController.h