# Steemex
Elixir HTTP/Websockets client for Steem JSONRPC interface and official Steemit API.
## Installation
1. Add `steemex` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:steemex, ">= 0.0.0"}
]
end
```
## Configuration
Stemeex doesn't require any configuration. If no config is provided, Steemex will use `http://api.steemit.com` condenser endpoint for all JSONRPC calls.
If you want to use another transport, public node or private node, set corresponding values for `api` and `api_url`. Possible api values are `:steemit_api`, `:jsonrpc_ws_api`, `:jsonrpc_http_api`.
If you are using http or ws api, you need to set a steemd instance url, for example, a public node `http://gtg.steem.house:8090` for jsonrpc_http_api.
Example:
```elixir
config :steemex,
api: :jsonrpc_http_api,
api_url: "http://gtg.steem.house:8090",
activate_stage_sup: false
```
If want Steemex to stream incoming events in pseudo-realtime, set `activate_stage_sup` to `true` and see the example of a GenStage consumer.
# JSONRPC API
Steemex module includes structs for all operations types. Streamer module parses each operation and converts it to a corresponding struct.
The main module function is `Steemex.call`. It will block the calling process and return a success tuple with a "result" data from the JSONRPC call response. JSONRPC call ids are handled automatically.
# Documentation
All database api functions have docs, typespecs and example API responses.
# GenStage
Steemex uses GenStage, [a new specification](http://elixir-lang.org/blog/2016/07/14/announcing-genstage/) 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
## An example of GenStage consumer to handle stream of new operations
```
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
Steemex is under active development.
* Add more utility functions
* Add more types and structs
* Add transaction broadcasting