Wechat API wrapper in Elixir.

1. Add wechat to your list of dependencies in mix.exs:

   def deps do
     [{:wechat, "~> 0.1.0"}]
   end

2. Ensure wechat is started before your application:

   def application do
     [applications: [:wechat]]
   end

• Add config in config.exs

  config :wechat, Wechat,
    appid: "wechat app id",
    secret: "wechat app secret",
    token: "wechat token",
    encoding_aes_key: "32bits key" # 只有"兼容模式"和"安全模式"才需要配置这个值

• access_token

  iex> Wechat.access_token

"Bgw6_cMvFrE3hY3J8U6oglhvlzHhMpAQma0Wjam4XsLx8F6XP4pfZzsezBdpfth2BNAdUK6wA23S7D3fSePt7meG9a1gf9LhEmXjxGelnTjJLaIQMYumrCHE_9gcFVXaHIHcAGACDC" ```

• user

  iex> Wechat.User.list
  %{count: 4,
  data: %{openid: ["oi00OuFrmNEC-QMa0Kikycq6A7ys",
   "oi00OuKAhA8bm5okpaIDs7WmUZr4", "oi00OuOdjK0TicVUmovudbSP5Zq4",
   "oi00OuBgG2mko_pOukCy00EYCwo4"]},
  next_openid: "oi00OuBgG2mko_pOukCy00EYCwo4", total: 4}
  
  iex> Wechat.User.info("oi00OuKAhA8bm5okpaIDs7WmUZr4")
  %{city: "宝山", country: "**", groupid: 0,
  headimgurl: "http://wx.qlogo.cn/mmopen/7raJSSs9gLVJibia6sAXRvr8jajXfQFWiagrLwrRIZjMHCEXOxYf6nflxcpl4WkT7gz8Sa4tO32avnI0dlNLn24yA/0",
  language: "zh_CN", nickname: "小爆炸的爸爸",
  openid: "oi00OuKAhA8bm5okpaIDs7WmUZr4", province: "上海", remark: "",
  sex: 1, subscribe: 1, subscribe_time: 1449812483, tagid_list: [],
  unionid: "o2oUsuOUzgNL-JSLtIp8b3FzkI-M"}

• media

  iex> file = Wechat.Media.download("GuSq91L0FXQFOIFtKwX2i5UPXH9QKnnu63_z4JHZwIw3TMIn1C-xm8hX3nPWCA")
  iex> File.write!('/tmp/file', file)

• Wechat.Plugs.CheckUrlSignature

  • Check url signature
  • 接入指南

• Wechat.Plugs.CheckMsgSignature

  • Parse xml message (support decrypt msg)
  • 消息加密解密技术方案

• router.ex

  defmodule MyApp.Router do
    pipeline :api do
      plug :accepts, ["json"]
    end
  
    scope "/wechat", MyApp do
      pipe_through :api
  
      # validate wechat server config
      get "/", WechatController, :index
  
      # receive wechat push message
      post "/", WechatController, :create
    end
  end

• wechat_controller.ex

  defmodule MyApp.WechatController do
    use MyApp.Web, :controller
  
    plug Wechat.Plugs.CheckUrlSignature
    plug Wechat.Plugs.CheckMsgSignature when action in [:create]
  
    def index(conn, %{"echostr" => echostr}) do
      text conn, echostr
    end
  
    def create(conn, _params) do
      msg = conn.assigns[:msg]
      reply = build_text_reply(msg, msg.content)
      render conn, "text.xml", reply: reply
    end
  
    defp build_text_reply(%{tousername: to, fromusername: from}, content) do
      %{from: to, to: from, content: content}
    end
  end

• text.xml.eex

  <xml>
    <MsgType><![CDATA[text]]></MsgType>
    <Content><![CDATA[<%= @reply.content %>]]></Content>
    <ToUserName><![CDATA[<%= @reply.to %>]]></ToUserName>
    <FromUserName><![CDATA[<%= @reply.from %>]]></FromUserName>
    <CreateTime><%= DateTime.to_unix(DateTime.utc_now) %></CreateTime>
  </xml>