This release includes improvements and bugfixes I've made over the past few months. Noteworthy changes: 1) erlang websockets client library was replaced by elixir websockex package 2) jsonrpc responses are parsed to native datatypes for elixir, for example, NaiveDateTime for timestamp.

Repos and docs

• github
• hex.pm
• docs

GenStage event producers

Steemex uses GenStage, a new specification for handling and exchanging events among Elixir/Erlang processes.

On module app startup two GenStage processes are started and registered:

Steemex.Stage.Blocks.Producer which, perhaps unsurprisingly, is a new blocks producer
Steemex.Stage.RawOps produces raw blockchain operations
Steemex.Stage.MungedOps produces parsed, cleaned and transformed operations

A GenStage consumer example

defmodule Steemex.Stage.ExampleConsumer do
  use GenStage
  alias Steemex.MungedOps
  require Logger

  def start_link(args, options \\ []) do
    GenStage.start_link(__MODULE__, args, options)
  end

  def init(state) do
    Logger.info("Example consumer is initializing...")
    {:consumer, state, subscribe_to: state[:subscribe_to]}
  end

  def handle_events(events, _from, state) do
    for op <- events do
      process_event(op)
    end
    {:noreply, [], state}
  end

  def process_event(%{data: %MungedOps.Reblog{} = data, metadata: %{height: h, timestamp: t} = metadata}) do
      Logger.info """
      New reblog:
      #{inspect data}
      with metadata
      #{inspect metadata}
      """
  end

  def process_event(%{data: data, metadata: %{block_height: h, timestamp: t} = metadata}) do
      Logger.info """
      New operation:
      #{inspect data}
      with metadata
      #{inspect metadata}
      """
  end

end

Roadmap

• Add latest blockchain ops
• Add more structured ops and transformations
• Add transaction broadcast

About Elixir

Elixir is a functional programming language with superior concurrency primitives, distributed computation and fault tolerance capabilities based on Erlang/OTP.
Personally, I am really happy with my bet on Elixir to build cryptotokens related apps and strongly recommend every developer to try it.

Learning resources:

• ElixirConf Jose Valim Keynote
• ElixirConf 2016 Chris McCord Keynote
• Elixir School
• Elixir Crash Course

(∩^o^)⊃━☆゜.*