Exrecaptcha

Simple ReCaptcha display/verify code for Elixir applications. Using Exrecaptcha with a CMS such as Phoenix is easy.

Installation

Set as a dep in your mix.exs and ensure it is running with your app:

  def application do
    [
      # ...
      applications: [:phoenix, :cowboy, :logger, :exrecaptcha]
      # ...
    ]
  end
  
  defp deps do
    [
      {:phoenix, "0.4.1"},
      {:cowboy, "~> 1.0.0"},
      # ...
      {:exrecaptcha, github: "adanselm/exrecaptcha"}
    ]

And fetch your project's dependencies:

$ mix deps.get

Config

In your application's config.exs :

config :exrecaptcha,
  api_config: %{ verify_url: "http://www.google.com/recaptcha/api/verify",
                 public_key: "YOUR_PUBLIC_KEY",
                 private_key: "YOUR_PRIVATE_KEY" }

You can use https instead of http for the verify_url.

Usage

View

Put this code somewhere in your html template:

<form id="loginForm" name="newuser" method="post" action="/users">
  ...
  <%= safe Exrecaptcha.display %>
  ...
</form>

Controller

Provided you've set the routing properly, you just have to call

# your post method should route you here:
def create(conn, params) do
  # do stuff, then check for the validity of the captcha
  :ok = verify_captcha(conn, params)
end

defp verify_captcha(conn, %{"recaptcha_challenge_field" => challenge,
                            "recaptcha_response_field" => response}) do
  remote_ip = conn.remote_ip
  Exrecaptcha.verify(remote_ip, challenge, response)
end

##TODO

• No option for recaptcha display can be set yet
• Error handling is quite inexistent (throws RuntimeError)
• No tests (if you have an idea how I can test that, I'm all ears)

Licensing

Copyright © 2014 Adrien Anselme and contributors This work is free. You can redistribute it and/or modify it under the terms of the Do What The Fuck You Want To Public License, Version 2, as published by Sam Hocevar. See the COPYING file for more details.