Tide Hex.pmBuild Status

Similar to elixir/export but design for asynchronous.

Installation

Adding tide to your list of dependencies in mix.exs:

def deps do
  [
    {:tide, "~> 0.2.1"}
  ]
end

Usage

Start Tide.Supervisor to create Ruby worker pool

children = [
  {Tide.Supervisor, root: :code.priv_dir(:app_name) |> Path.join("ruby"), file: "app"},
  # ...
]
options = [strategy: :one_for_one, name: __MODULE__]

Supervisor.start_link(children, options)

Register Event

Create a Ruby script (e.g. priv/ruby/app.rb) and put your code

# Immediately will use the return value
Elixir::Tide.on("say") do |name|
  reply :ok, "Hello #{name}"
end

# Async event use "Tide.Agent.emit"
Elixir::Tide.on("sleep") do |wait_time|
  sleep wait_time.to_i
  reply :ok, "I am awake!"
end

Agent

Start a Tide.Agent to manage events

{:ok, pid} = Tide.Agent.start_link()

Execute event (return immediately)

{:ok, message } = Tide.Agent.exec(pid, "say", ["World"])
# => "Hello World"

Emit event (asynchronous, and managed by Tide.Reaction)

{:ok, message } = Tide.Agent.emit(pid, "sleep", [1])
# After 1 seconds
{:ok, message } =
  Tide.Agent.reaction(pid)
  |> Tide.Reaction.next

# => "I am awake!"

Reaction

The Tide.Reaction is a queue collect the reply from Ruby. You can use it to prevent the Tide.Agent.exec blocking your process.

State

The Erlport didn't support call Erlang function from Thread, and to ensure your Ruby script can recover from crash. Use the Tide.State to persist the state and it will pass to Ruby by Tide.

Attach a state to agent

{:ok, state} = Tide.State.start_link()
{:ok, agent} = Tide.Agent.start_link(state)

When we execute an event the state will convert to keyword list and save as Tide::State object. That means the Map or Keyword List is accept as a state.

state = %{user_id: 1, name: "John"}
{:ok, agent} = Tide.Agent.start_link(state)

The state is part of agent and unable directly change it, but we can use Tide.Agent.update/2 to update it.

agent
|> Tide.Agent.update(fn(state) -> state |> Map.put(:name, "Bob")  end)

Or replace state to another new state

agent
|> Tide.Agent.update(%{user_id: 1, name: "Alice"})

Roadmap