PTDiffusionJSONValueUpdater Class Reference

Introduction

A JSON value updater may be used to update JSON topics by specifying new values.

See Also

PTDiffusionTopicUpdateControlFeature

PTDiffusionTopicUpdater

Since

6.0

Inheritance diagram for PTDiffusionJSONValueUpdater:

Instance Methods
(BOOL)	- getCachedValue:forTopicPath:error:
(void)	- updateWithTopicPath:value:completionHandler:
Instance Methods inherited from PTDiffusionValueUpdater
(instancetype)	- NS_UNAVAILABLE
(void)	- removeCachedValuesWithTopicSelector:
(void)	- removeCachedValuesWithSelectorExpression:

Additional Inherited Members
Class Methods inherited from PTDiffusionValueUpdater
(instancetype)	+ NS_UNAVAILABLE

Method Documentation

- (BOOL) getCachedValue:		(PTDiffusionJSON *_Nullable *_Nonnull)	value
forTopicPath:		(NSString *)	topicPath
error:		(NSError **)	error

Returns the current cached value for a given topic path.

Parameters

value	On successful return then set to the current cached value or nil if there is no value for the given path. There may be no value because no value has yet been sent, or the value has been removed from the cache.
topicPath	Specifies the topic to obtain the current value for.
error	If an error occurs, upon return contains an NSError object that describes the problem.

Returns

YES if there is no cached value for the given topic path or if the cached entry for the given topic path is of the correct type. In either of these cases the value will be assigned appropriately. Otherwise this method returns NO and error will be assigned with a failure reason.

Exceptions

NSInvalidArgumentException

If either of the value or topicPath arguments are nil.

Since

6.0

- (void) updateWithTopicPath:		(NSString *)	topicPath
value:		(PTDiffusionJSON *)	value
completionHandler:		(NSError *_Nullable error)	completionHandler

Updates a topic to a specified value.

For exclusive updating, this method caches the supplied value so that subsequent calls for the same topic will be able to use the current value to calculate deltas of change to send to the server rather than having to send the whole value.

For non-exclusive updating, the complete value is always sent to the server and the value is not cached.

Parameters

topicPath	Specifies the topic to be updated.
value	The new value for the topic.
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. The completion handler will be called asynchronously on the main dispatch queue.

Exceptions

NSInvalidArgumentException

If any of the supplied arguments are nil.

Since

6.0