LiveState.Channel behaviour (live_state v0.6.1)

To build a LiveState application, you'll first want to add a channel that implements this behaviour.

Link to this section Summary

Callbacks

Called from join to authorize the connection. Return {:ok, socket} to authorize or {:error, reason} to deny. Default implementation returns {:ok, socket}

Receives an event an payload from the client and current state. Return a :reply tuple if you need to send events to the client, otherwise return :noreply. :reply tuples can contain a single LiveState.Event or a list of events as well as the new state.

Receive an event name, payload, the current state, and the socket. Use this callback if you need to receive the socket as well as the state. Return a :reply tuple if you need to send events to the client, otherwise return :noreply. :reply tuples can contain a single LiveState.Event or a list of events, as well as the new state and the socket. :noreply tuples must contain the new state and and socket.

Receives pubsub message and current state. Returns new state

Returns the initial application state. Called just after connection

The key on assigns to hold application state. Defaults to :state.

The key on assigns to hold application state version. Defaults to :version.

Link to this section Callbacks

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authorize(channel, payload, socket)

@callback authorize(channel :: binary(), payload :: term(), socket :: Socket.t()) ::
  {:ok, socket :: Socket.t()} | {:error, binary()}

Called from join to authorize the connection. Return {:ok, socket} to authorize or {:error, reason} to deny. Default implementation returns {:ok, socket}

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handle_event(event_name, payload, state)

(optional)
@callback handle_event(event_name :: binary(), payload :: term(), state :: term()) ::
  {:reply,
   reply ::
     %LiveState.Event{detail: term(), name: term()}
     | [%LiveState.Event{detail: term(), name: term()}], new_state :: any()}
  | {:noreply, new_state :: map()}

Receives an event an payload from the client and current state. Return a :reply tuple if you need to send events to the client, otherwise return :noreply. :reply tuples can contain a single LiveState.Event or a list of events as well as the new state.

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handle_event( event_name, payload, state, socket )

(optional)
@callback handle_event(
  event_name :: binary(),
  payload :: term(),
  state :: term(),
  socket :: Socket.t()
) ::
  {:reply,
   reply ::
     %LiveState.Event{detail: term(), name: term()}
     | [%LiveState.Event{detail: term(), name: term()}], new_state :: map(),
   Socket.t()}
  | {:noreply, new_state :: map(), Socket.t()}

Receive an event name, payload, the current state, and the socket. Use this callback if you need to receive the socket as well as the state. Return a :reply tuple if you need to send events to the client, otherwise return :noreply. :reply tuples can contain a single LiveState.Event or a list of events, as well as the new state and the socket. :noreply tuples must contain the new state and and socket.

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handle_message(message, state)

@callback handle_message(message :: term(), state :: term()) ::
  {:reply,
   reply ::
     %LiveState.Event{detail: term(), name: term()}
     | [%LiveState.Event{detail: term(), name: term()}], new_state :: any()}
  | {:noreply, new_state :: term()}

Receives pubsub message and current state. Returns new state

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init(channel, payload, socket)

@callback init(channel :: binary(), payload :: term(), socket :: Socket.t()) ::
  {:ok, state :: map()}
  | {:ok, state :: map(), Socket.t()}
  | {:error, reason :: any()}

Returns the initial application state. Called just after connection

@callback state_key() :: atom()

The key on assigns to hold application state. Defaults to :state.

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state_version_key()

@callback state_version_key() :: atom()

The key on assigns to hold application state version. Defaults to :version.