# HTTPoison [](https://travis-ci.org/edgurgel/httpoison) [](https://hex.pm/packages/httpoison) [](https://hex.pm/packages/httpoison)
HTTP client for Elixir, based on
[HTTPotion](https://github.com/myfreeweb/httpotion)
([documentation](http://hexdocs.pm/httpoison/)).
## But... why something so similar to HTTPotion?
HTTPoison uses hackney to execute HTTP requests instead of ibrowse. I like hackney :thumbsup:
Using hackney we work only with binaries instead of string lists.
## Installation
First, add HTTPoison to your `mix.exs` dependencies:
```elixir
def deps do
[{:httpoison, "~> 0.8.0"}]
end
```
and run `$ mix deps.get`. Now, list the `:httpoison` application as your
application dependency:
```elixir
def application do
[applications: [:httpoison]]
end
```
### If you're on Ubuntu
Make sure you have `erlang-dev` installed before using `httpoison`.
You can do so by running:
```sh
apt-get install erlang-dev
```
## Usage
```iex
iex> HTTPoison.start
iex> HTTPoison.get! "http://httparrot.herokuapp.com/get"
%HTTPoison.Response{
body: "{\n \"args\": {},\n \"headers\": {} ...",
headers: headers: [{"Connection", "keep-alive"}, {"Server", "Cowboy"},
{"Date", "Sat, 06 Jun 2015 03:52:13 GMT"}, {"Content-Length", "495"},
{"Content-Type", "application/json"}, {"Via", "1.1 vegur"}],
status_code: 200
}
iex> HTTPoison.get! "http://localhost:1"
** (HTTPoison.Error) :econnrefused
iex> HTTPoison.get "http://localhost:1"
{:error, %HTTPoison.Error{id: nil, reason: :econnrefused}}
```
You can also easily pattern match on the `HTTPoison.Response` struct:
```elixir
case HTTPoison.get(url) do
{:ok, %HTTPoison.Response{status_code: 200, body: body}} ->
IO.puts body
{:ok, %HTTPoison.Response{status_code: 404}} ->
IO.puts "Not found :("
{:error, %HTTPoison.Error{reason: reason}} ->
IO.inspect reason
end
```
### Wrapping `HTTPoison.Base`
You can also use the `HTTPoison.Base` module in your modules in order to make
cool API clients or something. The following example wraps `HTTPoison.Base` in
order to build a client for the GitHub API
([Poison](https://github.com/devinus/poison) is used for JSON decoding):
```elixir
defmodule GitHub do
use HTTPoison.Base
@expected_fields ~w(
login id avatar_url gravatar_id url html_url followers_url
following_url gists_url starred_url subscriptions_url
organizations_url repos_url events_url received_events_url type
site_admin name company blog location email hireable bio
public_repos public_gists followers following created_at updated_at
)
def process_url(url) do
"https://api.github.com" <> url
end
def process_response_body(body) do
body
|> Poison.decode!
|> Dict.take(@expected_fields)
|> Enum.map(fn({k, v}) -> {String.to_atom(k), v} end)
end
end
```
```iex
iex> GitHub.start
iex> GitHub.get!("/users/myfreeweb").body[:public_repos]
37
```
It's possible to extend the functions listed below:
```elixir
defp process_request_body(body), do: body
defp process_response_body(body), do: body
defp process_request_headers(headers) when is_map(headers) do
Enum.into(headers, [])
end
defp process_request_headers(headers), do: headers
defp process_response_chunk(chunk), do: chunk
defp process_headers(headers), do: headers
defp process_status_code(status_code), do: status_code
```
### Async requests
HTTPoison now comes with async requests!
```iex
iex> HTTPoison.get! "https://github.com/", %{}, stream_to: self
%HTTPoison.AsyncResponse{id: #Reference<0.0.0.1654>}
iex> flush
%HTTPoison.AsyncStatus{code: 200, id: #Reference<0.0.0.1654>}
%HTTPoison.AsyncHeaders{headers: %{"Connection" => "keep-alive", ...}, id: #Reference<0.0.0.1654>}
%HTTPoison.AsyncChunk{chunk: "<!DOCTYPE html>...", id: #Reference<0.0.0.1654>}
%HTTPoison.AsyncEnd{id: #Reference<0.0.0.1654>}
:ok
```
You can see more usage examples in the test files (located in the
[`test/`](test)) directory.
## License
Copyright © 2013-2014 Eduardo Gurgel <eduardo@gurgel.me>
This work is free. You can redistribute it and/or modify it under the
terms of the MIT License. See the LICENSE file for more details.
