ditto::StoreObserver Class Reference

Public Member Functions
	StoreObserver (StoreObserver &&)
StoreObserver &	operator= (StoreObserver &&)
	StoreObserver (const StoreObserver &)=delete
StoreObserver &	operator= (const StoreObserver &)=delete
bool	operator< (const StoreObserver &other) const
void	cancel ()
	Cancels the observation. The handler that was passed in when registering this store observer will no longer be called. No-op if this store observer is already cancelled or the owning Ditto object goes out of scope.
bool	is_cancelled ()
	Convenience property, returns true if the store observer has been cancelled, otherwise returns false. Also, a store observer is considered cancelled if the owning Ditto object goes out of scope.
std::string	get_query () const
	Returns the query string that was used to create the observer.
nlohmann::json	get_query_arguments () const
	Returns the query arguments that were used to create the observer.
std::vector< uint8_t >	get_query_arguments_cbor_data () const
	Returns the query arguments that were used to create the observer, as a CBOR-encoded byte vector.
std::string	get_query_arguments_json_string () const
	Returns the query arguments that were used to create the observer, as a JSON-encoded string.

Detailed Description

A store observer invokes a change handler whenever results for its query change.

Create a store observer by calling Store::register_observer.

Member Function Documentation

get_query_arguments()

nlohmann::json ditto::StoreObserver::get_query_arguments

(

)

const

Returns the query arguments that were used to create the observer.

Note

The returned value is not guaranteed to be strictly equal to the value provided when making the call to Store::register_observer, as the arguments will have gone through a serialization roundtrip. This might affect equality checks, particularly for non-primitive values. If you want to have more control over how to deserialize the query arguments then use get_query_arguments_cbor_data or get_query_arguments_json_string.