#  Envío
[](https://circleci.com/gh/am-kantox/envio) **application-wide registry with handy helpers to ease dispatching**
## Installation
Simply add `envio` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:envio, "~> 0.3"}
]
end
```
## Usage
### Simple publisher
Use `Envio.Publisher` helper to scaffold the registry publisher. It provides
`broadcast/2` helper (and `brodcast/1` if the default channel is set.)
```elixir
defmodule Spitter do
use Envio.Publisher, channel: :main
def spit(channel, what), do: broadcast(channel, what)
def spit(what), do: broadcast(what)
end
```
### Simple subscriber ([`dispatch`](https://hexdocs.pm/elixir/master/Registry.html#module-using-as-a-dispatcher))
Just register your handler anywhere in the code:
```elixir
Envio.register(
{Sucker, :suck},
dispatch: %Envio.Channel{source: Spitter, name: :foo}
)
```
`Sucker.suck/1` will be called with a payload.
### PubSub subscriber ([`pub_sub`](https://hexdocs.pm/elixir/master/Registry.html#module-using-as-a-pubsub))
Use `Envio.Subscriber` helper to scaffold the registry subscriber. Implement
`handle_envio/2` for custom message handling. The default implementation
collects last 10 messages in it’s state.
```elixir
defmodule PubSucker do
use Envio.Subscriber, channels: [{Spitter, :foo}]
def handle_envio(message, state) do
{:noreply, state} = super(message, state)
IO.inspect({message, state}, label: "PubSucked")
{:noreply, state}
end
end
```
## Changelog
* `0.3.0` → `Envio.Backend` and infrastructure for backends; `Slack` as an example.
## ToDo
* Back pressure with [`GenStage`](https://hexdocs.pm/gen_stage/GenStage.html)
for `:dispatch` kind of delivery;
* Set of backends for easy delivery (_slack_, _redis_, _rabbit_, etc.)
## [Documentation](https://hexdocs.pm/envio)
