spoke/core

Types

Command

A command to be performed, as requested by the user of the client.

pub type Command {
  SubscribeToUpdates(drift.Effect(mqtt.Update))
  UnsubscribeFromUpdates(drift.Effect(mqtt.Update))
  Connect(
    clean_session: Bool,
    will: option.Option(mqtt.PublishData),
  )
  Disconnect(drift.Effect(Nil))
  Subscribe(
    List(mqtt.SubscribeRequest),
    drift.Effect(
      Result(List(mqtt.Subscription), mqtt.OperationError),
    ),
  )
  Unsubscribe(
    List(String),
    drift.Effect(Result(Nil, mqtt.OperationError)),
  )
  PublishMessage(mqtt.PublishData)
  GetPendingPublishes(drift.Effect(Int))
  WaitForPublishesToFinish(
    drift.Effect(Result(Nil, mqtt.OperationError)),
    Int,
  )
}

Constructors

```
SubscribeToUpdates(drift.Effect(mqtt.Update))
```
Registers an effect to be invoked when updates are available.
```
UnsubscribeFromUpdates(drift.Effect(mqtt.Update))
```
Unregisters an effect from being invoked on updates.

Connect(
  clean_session: Bool,
  will: option.Option(mqtt.PublishData),
)

Starts connecting to the borker.

```
Disconnect(drift.Effect(Nil))
```
Disconnects from the broker

Subscribe(
  List(mqtt.SubscribeRequest),
  drift.Effect(
    Result(List(mqtt.Subscription), mqtt.OperationError),
  ),
)

Starts a subscribing to topics.

Unsubscribe(
  List(String),
  drift.Effect(Result(Nil, mqtt.OperationError)),
)

Starts unsubscribing from topics.

```
PublishMessage(mqtt.PublishData)
```
Starts publishing a message.
```
GetPendingPublishes(drift.Effect(Int))
```
Requests for the number of in-progress publishes.

WaitForPublishesToFinish(
  drift.Effect(Result(Nil, mqtt.OperationError)),
  Int,
)

Starts waiting for publishes to finish.

Context

</>

Type alias for the drift context.

pub type Context =
  drift.Context(Input, Output)

Input

</>

The union of all the possible inputs

pub type Input {
  Perform(Command)
  Handle(TransportEvent)
  Timeout(TimedAction)
}

Constructors

```
Perform(Command)
```
```
Handle(TransportEvent)
```
```
Timeout(TimedAction)
```

Output

</>

All the outputs (side effects)

pub type Output {
  Publish(drift.Action(mqtt.Update))
  OpenTransport
  CloseTransport
  SendData(bytes_tree.BytesTree)
  ReturnPendingPublishes(drift.Action(Int))
  PublishesCompleted(
    drift.Action(Result(Nil, mqtt.OperationError)),
  )
  SubscribeCompleted(
    drift.Action(
      Result(List(mqtt.Subscription), mqtt.OperationError),
    ),
  )
  UnsubscribeCompleted(
    drift.Action(Result(Nil, mqtt.OperationError)),
  )
  CompleteDisconnect(drift.Action(Nil))
  UpdatePersistedSession(session_state.StorageUpdate)
}

Constructors

```
Publish(drift.Action(mqtt.Update))
```
Publish an update the user of the client.
```
OpenTransport
```
Open the transport channel.
```
CloseTransport
```
Close the transport channel.
```
SendData(bytes_tree.BytesTree)
```
Send data to the transport channel.
```
ReturnPendingPublishes(drift.Action(Int))
```
Publish the result for the count of pending publishes.

PublishesCompleted(
  drift.Action(Result(Nil, mqtt.OperationError)),
)

Waiting for publishes completed.

SubscribeCompleted(
  drift.Action(
    Result(List(mqtt.Subscription), mqtt.OperationError),
  ),
)

Subscribing to topics completed.

UnsubscribeCompleted(
  drift.Action(Result(Nil, mqtt.OperationError)),
)

Unsubscribing from topics completed.

```
CompleteDisconnect(drift.Action(Nil))
```
A disconnect request completed.

UpdatePersistedSession(session_state.StorageUpdate)

Apply an update to a persisted session.

State

opaque </>

The state of the MQTT client.

pub opaque type State

Step

</>

Type alias for the drift step.

pub type Step =
  drift.Step(State, Input, Output, String)

TimedAction

opaque </>

An action that happens as a result of timer expiring

pub opaque type TimedAction

TransportEvent

</>

An event coming from the transport channel

pub type TransportEvent {
  TransportEstablished
  TransportFailed(String)
  TransportClosed
  ReceivedData(BitArray)
}

Constructors

```
TransportEstablished
```
The transport channel is open, and ready to receive data.
```
TransportFailed(String)
```
The transport channel failed for some reason.
```
TransportClosed
```
The transport channel was closed after requesting it.
```
ReceivedData(BitArray)
```
Data was received on the transport channel.

Values

handle_input

</>

pub fn handle_input(
  context: drift.Context(Input, Output),
  state: State,
  input: Input,
) -> drift.Step(State, Input, Output, String)

Runs one step, handing the given input.

new_state

</>

pub fn new_state(options: mqtt.ConnectOptions(a)) -> State

Creates new, clean state.

restore_state

</>

pub fn restore_state(
  options: mqtt.ConnectOptions(a),
  state: session_state.SessionState,
) -> State

Creates a new state from an existing session.