Init for opensource

.gitignore

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+# The directory Mix will write compiled artifacts to.
+/_build
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover
+
+# The directory Mix downloads your dependencies sources to.
+/deps
+
+# Where 3rd-party dependencies like ExDoc output generated docs.
+/doc
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+.DS_Store

.travis.yml

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+language: elixir
+elixir:
+  - 1.4.5

README.md

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+# EventBus
+
+[![Build Status](https://travis-ci.org/mustafaturan/event_bus.svg?branch=master)](https://travis-ci.org/mustafaturan/event_bus)
+
+Simple event bus implementation.
+
+## Installation
+
+The package can be installed by adding `event_bus` to your list of dependencies in `mix.exs`:
+
+```elixir
+def deps do
+  [{:event_bus, "~> 0.1.0"}]
+end
+```
+
+## Usage
+
+Module docs can be found at [https://hexdocs.pm/event_bus](https://hexdocs.pm/event_bus).
+
+Subscribe to the 'event bus'
+```elixir
+EventBus.subscribe(MyEventListener)
+```
+
+Unsubscribe from the 'event bus'
+```elixir
+EventBus.unsubscribe(MyEventListener)
+```
+
+List subscribers
+```elixir
+EventBus.subscribers()
+```
+
+Notify all subscribers with any type of data
+```elixir
+EventBus.notify(:hello_received, %{message: "Hello"})
+EventBus.notify(:bye_received, [user_id: 1, goal: "exit"])
+```
+
+### Sample Listener Implementation
+
+```elixir
+defmodule MyEventListener do
+  ...
+
+  def process({:hello_received, _event_data} = event) do
+    GenServer.cast(__MODULE__, event)
+  end
+  def process({:bye_received, event_data}) do
+    # do sth
+    :ok
+  end
+  def process({event_type, event_data}) do
+    # this one matches all events
+    :ok
+  end
+
+  ...
+end
+```
+
+## Todo
+
+- [ ] Move event data to ETS and pass key instead of data to listeners
+
+## Contributing
+
+### Issues, Bugs, Documentation, Enhancements
+
+1. Fork the project
+
+2. Make your improvements and write your tests(make sure you covered all the cases).
+
+3. Make a pull request.
+
+## License
+
+MIT

config/config.exs

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+# This file is responsible for configuring your application
+# and its dependencies with the aid of the Mix.Config module.
+use Mix.Config
+
+# This configuration is loaded before any dependency and is restricted
+# to this project. If another project depends on this project, this
+# file won't be loaded nor affect the parent project. For this reason,
+# if you want to provide default values for your application for
+# 3rd-party users, it should be done in your "mix.exs" file.
+
+# You can configure for your application as:
+#
+#     config :event_bus, key: :value
+#
+# And access this configuration in your application as:
+#
+#     Application.get_env(:event_bus, :key)
+#
+# Or configure a 3rd-party app:
+#
+#     config :logger, level: :info
+#
+
+# It is also possible to import configuration files, relative to this
+# directory. For example, you can emulate configuration per environment
+# by uncommenting the line below and defining dev.exs, test.exs and such.
+# Configuration from the imported file will override the ones defined
+# here (which is why it is important to import them last).
+#
+#     import_config "#{Mix.env}.exs"

coveralls.json

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+{
+  "skip_files": [
+    "test/support"
+  ],
+  "custom_stop_words": [
+    "defdelegate"
+  ]
+}

lib/event_bus.ex

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+defmodule EventBus do
+  @moduledoc """
+  Simple event bus implementation.
+  """
+
+  alias EventBus.EventManager
+  alias EventBus.SubscriptionManager
+
+  @doc """
+  Send event to all listeners.
+
+  ## Examples
+
+      EventBus.notify({:webhook_received, %{"message" => "Hi all!"}})
+      :ok
+
+  """
+  @spec notify({:atom, any()}) :: :ok
+  def notify({_event_type, _event_data} = event) do
+    EventManager.notify(subscribers(), event)
+  end
+
+  @doc """
+  Subscribe to the bus.
+
+  ## Examples
+
+      EventBus.subscribe(MyEventListener)
+      :ok
+
+  """
+  @spec subscribe(any()) :: :ok
+  defdelegate subscribe(listener), to: SubscriptionManager, as: :subscribe
+
+  @doc """
+  Unsubscribe from the bus.
+
+  ## Examples
+
+      EventBus.unsubscribe(MyEventListener)
+      :ok
+
+  """
+  @spec unsubscribe(any()) :: :ok
+  defdelegate unsubscribe(listener), to: SubscriptionManager, as: :unsubscribe
+
+  @doc """
+  List the subscribers to the bus.
+
+  ## Examples
+
+      EventBus.subscribers()
+      [MyEventListener]
+
+  """
+  @spec subscribers() :: list(any())
+  defdelegate subscribers, to: SubscriptionManager, as: :subscribers
+end

lib/event_bus/application.ex

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+defmodule EventBus.Application do
+  @moduledoc false
+
+  use Application
+  alias EventBus.EventManager
+  alias EventBus.SubscriptionManager
+
+  def start(_type, _args) do
+    import Supervisor.Spec, warn: false
+
+    children = [
+      worker(SubscriptionManager, [], id: make_ref(), restart: :permanent),
+      worker(EventManager, [], id: make_ref(), restart: :permanent)
+    ]
+
+    opts = [strategy: :one_for_one, name: EventBus.Supervisor]
+    Supervisor.start_link(children, opts)
+  end
+end

lib/event_bus/event_manager.ex

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+defmodule EventBus.EventManager do
+  @moduledoc """
+  Event Manager
+  """
+
+  require Logger
+  use GenServer
+
+  @logging_level :info
+
+  @doc false
+  def start_link do
+    GenServer.start_link(__MODULE__, nil, name: __MODULE__)
+  end
+
+  @doc false
+  def notify(listeners, {_event_type, _event_data} = event) do
+    GenServer.cast(__MODULE__, {:notify, listeners, event})
+  end
+
+  @doc false
+  def handle_cast({:notify, listeners, event}, state) do
+    Enum.each(listeners, fn listener ->
+      notify_listener(listener, event)
+    end)
+    {:noreply, state}
+  end
+
+  defp notify_listener(listener, event) do
+    try do
+      listener.process(event)
+    rescue
+      err ->
+        Logger.log(@logging_level,
+          fn -> "#{listener}.process/1 raised an error!\n#{inspect(err)}" end)
+    end
+  end
+end

lib/event_bus/subscription_manager.ex

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+defmodule EventBus.SubscriptionManager do
+  @moduledoc """
+  Subscription Manager
+  """
+
+  use GenServer
+
+  @doc false
+  def start_link do
+    GenServer.start_link(__MODULE__, nil, name: __MODULE__)
+  end
+
+  def init(_) do
+    {:ok, []}
+  end
+
+  @doc false
+  def subscribe(listener) do
+    GenServer.cast(__MODULE__, {:subscribe, listener})
+  end
+
+  @doc false
+  def unsubscribe(listener) do
+    GenServer.cast(__MODULE__, {:unsubscribe, listener})
+  end
+
+  @doc false
+  def subscribers do
+    GenServer.call(__MODULE__, {:subscribers})
+  end
+
+  @doc false
+  def handle_cast({:subscribe, listener}, state) do
+    state =
+      if Enum.any?(state, fn old_listener -> old_listener == listener end) do
+        state
+      else
+        [listener | state]
+      end
+    {:noreply, state}
+  end
+
+  @doc false
+  def handle_cast({:unsubscribe, listener}, state) do
+    {:noreply, List.delete(state, listener)}
+  end
+
+  @doc false
+  def handle_call({:subscribers}, _from, state) do
+    {:reply, state, state}
+  end
+end

mix.exs

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+defmodule EventBus.Mixfile do
+  use Mix.Project
+
+  def project do
+    [app: :event_bus,
+     version: "0.1.0",
+     elixir: "~> 1.4",
+     elixirc_paths: elixirc_paths(Mix.env),
+     build_embedded: Mix.env == :prod,
+     start_permanent: Mix.env == :prod,
+     description: description(),
+     package: package(),
+     deps: deps(),
+     dialyzer: [plt_add_deps: :transitive],
+     test_coverage: [tool: ExCoveralls],
+     docs: [extras: ["README.md"]]]
+  end
+
+  # Configuration for the OTP application
+  #
+  # Type "mix help compile.app" for more information
+  def application do
+    # Specify extra applications you'll use from Erlang/Elixir
+    [extra_applications: [:logger],
+     mod: {EventBus.Application, []}]
+  end
+
+  defp elixirc_paths(:test),
+    do: ["lib", "test/support"]
+  defp elixirc_paths(_),
+    do: ["lib"]
+
+  # Dependencies can be Hex packages:
+  #
+  #   {:my_dep, "~> 0.3.0"}
+  #
+  # Or git/path repositories:
+  #
+  #   {:my_dep, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
+  #
+  # Type "mix help deps" for more examples and options
+  defp deps do
+    [
+      {:dialyxir, "~> 0.5", only: [:dev], runtime: false},
+      {:excoveralls, "~> 0.7", only: [:test]},
+      {:ex_doc, "~> 0.16.2", only: [:dev]}
+    ]
+  end
+
+  defp description do
+    """
+    Simple event bus
+    """
+  end
+
+  defp package do
+    [name: :event_bus,
+     files: ["lib", "mix.exs", "README.md"],
+     maintainers: ["Mustafa Turan"],
+     licenses: ["MIT"],
+     links: %{"GitHub" => "https://github.com/mustafaturan/event_bus"}]
+  end
+end

mix.lock

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+%{"certifi": {:hex, :certifi, "1.2.1", "c3904f192bd5284e5b13f20db3ceac9626e14eeacfbb492e19583cf0e37b22be", [:rebar3], [], "hexpm"},
+  "dialyxir": {:hex, :dialyxir, "0.5.0", "5bc543f9c28ecd51b99cc1a685a3c2a1a93216990347f259406a910cf048d1d7", [:mix], [], "hexpm"},
+  "earmark": {:hex, :earmark, "1.2.2", "f718159d6b65068e8daeef709ccddae5f7fdc770707d82e7d126f584cd925b74", [:mix], [], "hexpm"},
+  "ex_doc": {:hex, :ex_doc, "0.16.2", "3b3e210ebcd85a7c76b4e73f85c5640c011d2a0b2f06dcdf5acdb2ae904e5084", [:mix], [{:earmark, "~> 1.1", [hex: :earmark, repo: "hexpm", optional: false]}], "hexpm"},
+  "excoveralls": {:hex, :excoveralls, "0.7.1", "3dd659db19c290692b5e2c4a2365ae6d4488091a1ba58f62dcbdaa0c03da5491", [:mix], [{:exjsx, ">= 3.0.0", [hex: :exjsx, repo: "hexpm", optional: false]}, {:hackney, ">= 0.12.0", [hex: :hackney, repo: "hexpm", optional: false]}], "hexpm"},
+  "exjsx": {:hex, :exjsx, "4.0.0", "60548841e0212df401e38e63c0078ec57b33e7ea49b032c796ccad8cde794b5c", [:mix], [{:jsx, "~> 2.8.0", [hex: :jsx, repo: "hexpm", optional: false]}], "hexpm"},
+  "hackney": {:hex, :hackney, "1.8.6", "21a725db3569b3fb11a6af17d5c5f654052ce9624219f1317e8639183de4a423", [:rebar3], [{:certifi, "1.2.1", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "5.0.2", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "1.0.1", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "1.0.2", [hex: :mimerl, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "1.1.1", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}], "hexpm"},
+  "idna": {:hex, :idna, "5.0.2", "ac203208ada855d95dc591a764b6e87259cb0e2a364218f215ad662daa8cd6b4", [:rebar3], [{:unicode_util_compat, "0.2.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm"},
+  "jsx": {:hex, :jsx, "2.8.2", "7acc7d785b5abe8a6e9adbde926a24e481f29956dd8b4df49e3e4e7bcc92a018", [:mix, :rebar3], [], "hexpm"},
+  "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], [], "hexpm"},
+  "mimerl": {:hex, :mimerl, "1.0.2", "993f9b0e084083405ed8252b99460c4f0563e41729ab42d9074fd5e52439be88", [:rebar3], [], "hexpm"},
+  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.1", "28a4d65b7f59893bc2c7de786dec1e1555bd742d336043fe644ae956c3497fbe", [:make, :rebar], [], "hexpm"},
+  "unicode_util_compat": {:hex, :unicode_util_compat, "0.2.0", "dbbccf6781821b1c0701845eaf966c9b6d83d7c3bfc65ca2b78b88b8678bfa35", [:rebar3], [], "hexpm"}}