Bus Class Reference


                    
                    
                    label

A name for the bus.

Declaration

Swift

public private(set) var label: String { get }

queue
Queue on which to execute publish/subscribe actions to ensure thread safety
Declaration
Swift

public private(set) var queue: DispatchQueue { get }


                    
                    
                    init(label:queue:)

Initialize a Causality Event Bus

Declaration

Swift

public init(label: String, queue: DispatchQueue = globalQueue)

Parameters

`label`	name to give the bus
`queue`	Queue for bookkeeping (e.g. to ensure publish/subscribe is thread safe)

Publish Event With Message


                    
                    
                    publish(event:message:)

Publish an event to the bus.

All subscribers to this event will have their handler called along with the associated message.

Declaration

Swift

public func publish<Event, Message>(event: Event, message: Message) where Event : Causality.AnyEvent<Message>

Parameters

`event`	Event to publish
`message`	Message to send in event

Publish Event With No Message


                    
                    
                    publish(event:)

Publish an event with no message

Declaration

Swift

public func publish<Event>(event: Event) where Event : Causality.AnyEvent<Causality.NoMessage>

Parameters


                                event

Event to publish

Subscribe Event w/ Subscription


                    
                    
                    subscribe(_:queue:handler:)

Add a subscriber to a specific event type

Declaration

Swift

@discardableResult
public func subscribe<Event, Message>(_ event: Event, queue: DispatchQueue? = nil, handler: @escaping (Causality.EventSubscription<Event, Message>, Message) -> Void) -> Causality.EventSubscription<Event, Message> where Event : Causality.AnyEvent<Message>

Parameters

`event`	The event to subscribe to.
`queue`	DispatchQueue to receive messages on. This will take precedence over any queue specified by the publisher.
`handler`	A handler that is called for each event of this type that occurs (on the specified queue)


                    
                    
                    subscribe(_:queue:handler:)

Add a subscriber to a specific event type

Declaration

Swift

@discardableResult
public func subscribe<Event, Message>(_ event: Event, queue: OperationQueue, handler: @escaping (Causality.EventSubscription<Event, Message>, Message) -> Void) -> Causality.EventSubscription<Event, Message> where Event : Causality.AnyEvent<Message>

Parameters

`event`	The event to subscribe to.
`queue`	OperationQueue to receive messages on. This will take precedence over any queue specified by the publisher.
`handler`	A handler that is called for each event of this type that occurs (on the specified queue)

Subscribe Event w/o Subscription


                    
                    
                    subscribe(_:queue:handler:)

Add a subscriber to an event

Declaration

Swift

@discardableResult
public func subscribe<Event, Message>(_ event: Event, queue: DispatchQueue? = nil, handler: @escaping (Message) -> Void) -> Causality.EventSubscription<Event, Message> where Event : Causality.AnyEvent<Message>

Parameters

`event`	The event to subscribe to.
`queue`	DispatchQueue to receive messages on. This will take precedence over any queue specified by the publisher.
`handler`	A handler that is called for each event of this type that occurs (on the specified queue)

Return Value

Subscription handle that is needed to unsubscribe to this event


                    
                    
                    subscribe(_:queue:handler:)

Add a subscriber to an event

Declaration

Swift

@discardableResult
public func subscribe<Event, Message>(_ event: Event, queue: OperationQueue, handler: @escaping (Message) -> Void) -> Causality.EventSubscription<Event, Message> where Event : Causality.AnyEvent<Message>

Parameters

`event`	The event to subscribe to.
`queue`	OperationQueue to receive messages on. This will take precedence over any queue specified by the publisher.
`handler`	A handler that is called for each event of this type that occurs (on the specified queue)

Return Value

Subscription handle that is needed to unsubscribe to this event

Unsubscribe Event


                    
                    
                    unsubscribe(_:)

Stop a particular subscription handler from listening to events anymore.

Declaration

Swift

public func unsubscribe<Event, Message>(_ subscription: Causality.EventSubscription<Event, Message>) where Event : Causality.AnyEvent<Message>

Parameters


                                subsription

The Subscription that was returned from subscribe()


                    
                    
                    unsubscribe(_:)

Unsubscribe an array of subscriptions

Declaration

Swift

public func unsubscribe<Event, Message>(_ subscriptions: [Causality.EventSubscription<Event, Message>]) where Event : Causality.AnyEvent<Message>

Parameters


                                subscriptions

Subscriptions to unsubscribe from

Bus Extension


                    
                    
                    hasState(_:)

Determine if a state has an existing value

Declaration

Swift

public func hasState<State, Value>(_ state: State) -> Bool where State : Causality.AnyState<Value>, Value : Equatable

Parameters


                                state

State to check

Return Value

True if state has an existing value; False otherwise.


                    
                    
                    getState(_:)

Get the last known value for a state

Declaration

Swift

public func getState<State, Value>(_ state: State) -> Value? where State : Causality.AnyState<Value>, Value : Equatable

Parameters


                                state

State to check

Return Value

Value of state

Publish Event With State


                    
                    
                    set(state:value:)

Publish an event to the bus.

All subscribers to this event will have their handler called along with the associated message.

Declaration

Swift

public func set<State, Value>(state: State, value: Value) where State : Causality.AnyState<Value>, Value : Equatable

Parameters

`state`	The state to set the value for
`value`	The value to set for the given state

Subscribe Event w/ Subscription


                    
                    
                    subscribe(_:queue:handler:)

Add a subscriber to a specific state type

Declaration

Swift

@discardableResult
public func subscribe<State, Value>(_ state: State, queue: DispatchQueue? = nil, handler: @escaping (Causality.StateSubscription<State, Value>, Value) -> Void) -> Causality.StateSubscription<State, Value> where State : Causality.AnyState<Value>, Value : Equatable

Parameters

`state`	The state to subscribe to.
`queue`	DispatchQueue to receive messages on. This will take precedence over any queue specified by the publisher.
`handler`	A handler that is called for each event of this type that occurs (on the specified queue)


                    
                    
                    subscribe(_:queue:handler:)

Add a subscriber to a specific state type

Declaration

Swift

@discardableResult
public func subscribe<State, Value>(_ state: State, queue: OperationQueue, handler: @escaping (Causality.StateSubscription<State, Value>, Value) -> Void) -> Causality.StateSubscription<State, Value> where State : Causality.AnyState<Value>, Value : Equatable

Parameters

`state`	The state to subscribe to.
`queue`	OperationQueue to receive messages on. This will take precedence over any queue specified by the publisher.
`handler`	A handler that is called for each event of this type that occurs (on the specified queue)

Subscribe State w/o Subscription


                    
                    
                    subscribe(_:queue:handler:)

Add a subscriber to a specific state type

Declaration

Swift

public func subscribe<State, Value>(_ state: State, queue: DispatchQueue? = nil, handler: @escaping (Value) -> Void) -> Causality.StateSubscription<State, Value> where State : Causality.AnyState<Value>, Value : Equatable

Parameters

`state`	The state to subscribe to.
`queue`	DispatchQueue to receive messages on. This will take precedence over any queue specified by the publisher.
`handler`	A handler that is called for each event of this type that occurs (on the specified queue)


                    
                    
                    subscribe(_:queue:handler:)

Add a subscriber to a specific state type

Declaration

Swift

public func subscribe<State, Value>(_ state: State, queue: OperationQueue, handler: @escaping (Value) -> Void) -> Causality.StateSubscription<State, Value> where State : Causality.AnyState<Value>, Value : Equatable

Parameters

`state`	The event type to subscribe to.
`queue`	OperationQueue to receive messages on. This will take precedence over any queue specified by the publisher.
`handler`	A handler that is called for each event of this type that occurs (on the specified queue)

Unsubscribe State


                    
                    
                    unsubscribe(_:)

Stop a particular subscription handler from listening to state changes anymore.

Declaration

Swift

public func unsubscribe<State, Value>(_ subscription: Causality.StateSubscription<State, Value>) where State : Causality.AnyState<Value>, Value : Equatable

Parameters


                                subscription

The Subscription that was returned from subscribe()


                    
                    
                    unsubscribe(_:)

Unsubscribe an array of subscriptions

Declaration

Swift

public func unsubscribe<State, Value>(_ subscriptions: [Causality.StateSubscription<State, Value>]) where State : Causality.AnyState<Value>, Value : Equatable

Parameters


                                subscriptions

Subscriptions to unsubscribe from