<center>![](http://i.imgur.com/QKOa4iu.png)</center>
I've been working to improve the developer experience for Steemex and this release does exactly that. I had to introduce some breaking changes but it was worth it. Stage.Blocks,  Stage.RawOps and Statge.MungedOps GenStage producers now emit events with the following shape : %Steem.Event{data: ..., metadata: ...}` where data is a new Steem blockchain operation struct (or a map) and metadata includes timestamp, block height, source blockchain, type and if the operation data was munged.

All event producers follow [GenStage](http://elixir-lang.org/blog/2016/07/14/announcing-genstage/) spec which allows you to easily patch into the transformation pipeline at any step: block producer, ops producer or munged ops producer.


# Repos and docs

* [github](https://github.com/cyberpunk-ventures/steemex)
* [hex.pm](https://hex.pm/packages/steemex)
* [docs](https://hexdocs.pm/steemex)


# Changelog

* breaking: event shape for GenStage pipeline changed from tuple to %Steemex.Event{} struct 
* breaking: all API responses are now structs or atom keyed maps
* all stages now emit %Steemex.Event{data: ..., metadata: ...} 
* added Steemex.Block struct
* added Steemex.Event struct
* Steemex.Stages.Ops.ProducerConsumer renamed to Steemex.Stages.RawOps
* Steemex.Stages.StructuredOps.ProducerConsumer renamed to Steemex.Stages.MungedOps
*  timestamp strings are now parsed into NaiveDateTime
* example consumer was updated to match a new shape of events
* multiple various code improvements

## 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](http://confreaks.tv/videos/elixirconf2016-keynote)
* [ElixirConf 2016 Chris McCord Keynote](http://confreaks.tv/videos/elixirconf2016-keynote)
* [Elixir School](https://elixirschool.com/)
* [Elixir Crash Course](http://elixir-lang.org/crash-course.html)

<center>(∩^o^)⊃━☆゜.*</center>