PTDiffusionRecoverableUpdateStream Class Reference

Inheritance diagram for PTDiffusionRecoverableUpdateStream:

Class Methods
(BOOL)	+ isErrorRecoverable:

Properties
ObjectType	value
BOOL	inRecovery

Instance Methods
(BOOL)	- validateWithCompletionHandler:error:
(BOOL)	- setValue:completionHandler:error:
(BOOL)	- recover:

Protected Attributes
	: NSObject+(instancetype)new

Method Documentation

isErrorRecoverable:

+ (BOOL) isErrorRecoverable:

(NSError *)

error

Indicates if the error is recoverable by the update stream.

Parameters

error

The error.

Returns

True if the error is recoverable, false otherwise.

Since

6.10

recover:

- (BOOL) recover:

(NSError **)

error

Begins the procedure to attempt recovery from a transient error.

Parameters

error

If this method returns NO to indicate that an error occurred then this will be populated with the reason for that failure.

Returns

YES on success; or NO if an error occurred, in which case *error will be populated with the failure reason.

Since

6.10

setValue:completionHandler:error:

- (BOOL) setValue:		(ObjectType)	value
completionHandler:		(PTDiffusionUpdateStreamHandlerBlock)	completionHandler
error:		(NSError **)	error

Sets the topic to a specified value.

The first call to this method may fail with a "no such topic" or "incompatible topic" error. Subsequent calls may fail with "invalid update stream". Any call can fail with a "cluster repartition", "session security" or "session closed" error.

If a PTDiffusionUpdateConstraint was provided when creating the update stream, the first call to this method may also fail with an "unsatisified constraint" error.

If the update stream was created with one of the "create update stream" methods, the first call to this method may also fail with an "incompatible existing topic" error and it will not fail with a "no such topic" error.

If this method fails all subsequent calls to 'set' or 'validate' will fail with an "invalid update stream" error.

If the task fails, the completionHandler will be called with an error. Common reasons for failure include:

• no such topic if there is no topic bound to path.
• incompatible topic if updates cannot be applied to the topic, for example if a topic view has bound a reference topic to the path.
• incompatible topic state if the topic is managed by a component (such as fan-out) that prohibits updates from the caller.
• unsatisfied constraint if the constraint is not satisfied by the topic path.
• invalid update stream if the update stream has been invalidated.
• invalid topic path if path is not a valid topic path.
• invalid topic specification if the specification is invalid, possibly because mandatory properties were not supplied.
• topic license limit if the topic could not be added as it would breach a licensing limit.
• cluster repartition if the cluster was repartitioning.
• session security if the calling session does not have the MODIFY_TOPIC or UPDATE_TOPIC permission for path.
• session closed if the session is closed.

Parameters

value	The value to set the topic to.
completionHandler	Block to be called asynchronously on success or failure. If the operation was successful, the error argument passed to the block will be nil and result will be non-nil. The completion handler will be called asynchronously on the main dispatch queue.
error	If this method returns NO to indicate that an error occurred then this will be populated with the reason for that failure.

Returns

YES on success; or NO if an error occurred, in which case *error will be populated with the failure reason.

Exceptions

NSInvalidArgumentException

If either value or completionHandler is nil.

Since

6.10

validateWithCompletionHandler:error:

- (BOOL) validateWithCompletionHandler:		(PTDiffusionUpdateStreamHandlerBlock)	completionHandler
error:		(NSError **)	error

Validates the update stream.

Update streams are validated lazily when setting the value. This method allows the stream to be validated before a value needs to be set.

If the update stream has not been validated yet, calling this method checks the topic exists, the topic type is correct, the constraint is satisfied and the session has permission to update the topic. Once it has been validated calling this method checks the topic has not been removed, no other stream has been created for the topic, the value of the topic has not been changed by anything else and the session still has permission to update the topic.

This method may fail with an "incompatible existing topic" error if it is the first call to validate, set has not been called and a PTDiffusionTopicSpecification was provided when creating the update stream, otherwise it will never fail with this error.

The first call to this method may fail with a "no such topic" or "incompatible topic" error. Subsequent calls may fail with "invalid update stream". Any call can fail with a "cluster repartition", "session security" or "session closed" error.

If a PTDiffusionUpdateConstraint was provided when creating the update stream, the first call to this method may also fail with an "unsatisified constraint" error.

If the update stream was created with one of the "create update stream" methods, the first call to this method may also fail with an "incompatible existing topic" error and it will not fail with a "no such topic" error.

If this method fails all subsequent calls to 'set' or 'validate' will fail with an "invalid update stream" error.

If the task fails, the completionHandler will be called with an error. Common reasons for failure include:

• no such topic if there is no topic bound to path.
• incompatible topic if updates cannot be applied to the topic, for example if a topic view has bound a reference topic to the path.
• incompatible topic state if the topic is managed by a component (such as fan-out) that prohibits updates from the caller.
• unsatisfied constraint if the constraint is not satisfied by the topic path.
• invalid update stream if the update stream has been invalidated.
• cluster repartition if the cluster was repartitioning.
• session security if the calling session does not have the MODIFY_TOPIC or UPDATE_TOPIC permission for path.
• session closed if the session is closed.

Parameters

completionHandler	Block to be called asynchronously on success or failure. If the operation was successful, the error argument passed to the block will be nil and result will be non-nil. The completion handler will be called asynchronously on the main dispatch queue.
error	If this method returns NO to indicate that an error occurred then this will be populated with the reason for that failure.

Returns

YES on success; or NO if an error occurred, in which case *error will be populated with the failure reason.

Exceptions

NSInvalidArgumentException

If completionHandler is `nil`.

Since

6.10

Property Documentation

inRecovery

- (BOOL) inRecovery

readatomicassign

Indicates if the recoverable update stream is currently in recovery.

Since

6.10

value

- (ObjectType) value

readnonatomicassign

The latest value of the topic set using this update stream, from local cache.

This value reflects the last value that has been set, before it is sent to the server.

If the server rejects a set operation, the topic value will not change and this update stream will be invalidated.

Since

6.10