PTDiffusionStringUpdateStream Class Reference

Introduction

An update stream that provides the ability for updating topics with string primitive values.

See also

PTDiffusionTopicUpdateFeature

Since

6.3

Inheritance diagram for PTDiffusionStringUpdateStream:

Properties
NSString *	value
Properties inherited from PTDiffusionUpdateStream
ObjectType	value

Instance Methods
(BOOL)	- setValue:completionHandler:error:
Instance Methods inherited from PTDiffusionUpdateStream
(BOOL)	- validateWithCompletionHandler:error:
(BOOL)	- setValue:completionHandler:error:

Additional Inherited Members
Protected Attributes inherited from PTDiffusionUpdateStream
	: NSObject+(instancetype)new

Method Documentation

setValue:completionHandler:error:

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

Sets the topic to a specified value or no value.

When a nil value is supplied to this method for a PTDiffusionTopicType_String topic, the topic will be updated to have no value. If a previous value was present subscribers will receive a notification that the new value is null. New subscribers will not receive a value notification.

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 completionHandler is `nil`.

Since

6.3

Property Documentation

value

- (NSString*) 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

6.3