hello_recaptcha_test.opa

/*
    Copyright © 2011, 2012 MLstate

    This file is part of OPA.

    OPA is free software: you can redistribute it and/or modify it under the
    terms of the GNU Affero General Public License, version 3, as published by
    the Free Software Foundation.

    OPA is distributed in the hope that it will be useful, but WITHOUT ANY
    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
    more details.

    You should have received a copy of the GNU Affero General Public License
    along with OPA.  If not, see <http://www.gnu.org/licenses/>.
*/
//Implement [Client.load]
//reCaptcha: api/recaptcha

import stdlib.web.client

bug = {true} //Replace by {false} to obtain something that works


type Recaptcha.success = {captcha_solved}
type Recaptcha.failure =
     {captcha_not_reachable}
 /   {upstream: string} /**Upstream error, code may be used for debugging purposes.*/
 /   {unknown: list(string)}
 /   {empty_answer}

type Recaptcha.result = {success: Recaptcha.success} / {failure: Recaptcha.failure}

type Recaptcha.config =
{
   private:
   {
      privkey: string
   }
   public:
   {
      pubkey:  string
      theme:   option(string)
   }
}

@abstract type Recaptcha.validator = (string, string, (Recaptcha.result -> void) -> void)

Recaptcha =
{{
   make(config: Recaptcha.config): (Recaptcha.validator, xhtml) =
   (
     id = Dom.fresh_id()
     xhtml = <div id={id} onready={_ -> onready(id, config.public.pubkey, config.public.theme?"red")}/>
     (validator(config.private.privkey), xhtml)
   )

   validate(validator: Recaptcha.validator, callback: Recaptcha.result -> void): void =
   (
      (a, b) = get_token()
      validator(a, b, callback)
   )

   @private path_api_uri = Option.get(Parser.try_parse(Uri.uri_parser, "http://www.google.com/recaptcha/api/verify"))
   @private path_js      = "http://www.google.com/recaptcha/api/js/recaptcha_ajax.js"

   @private onready(id: string, pubkey: string, theme: string): void =
   (
      do Log.info("onready", "start")
      Client.Script.load_from_then(path_js, ->
              do Log.info("onready", "loaded")
              do (%% Recaptcha.init %%)(id, pubkey, theme)
              do Log.info("onready", "initialized")
              void
              )
   )
   @private validator(privkey: string): Recaptcha.validator =
   (
      payload(challenge, response, callback:Recaptcha.result -> void) =
      (
        if String.is_empty(challenge) || String.is_empty(response) then callback({failure = {empty_answer}})
        else
        (
          data = [("privatekey", privkey),
                  ("remoteip",   "{HttpRequest.Generic.get_ip(Option.get(thread_context().request))}"),
                  ("challenge",  challenge),
                  ("response",   response)]
          with_result =
          (
            |  {failure = _} -> callback({failure = {captcha_not_reachable}})
            | ~{success} ->
              details = String.explode("\n", success.content)
              match details with
                | ["true" | _]        -> callback({success = {captcha_solved}})
                | ["false", code | _] -> callback({failure = {upstream = code}})
                | _ -> callback({failure = {unknown = details}})
           )
           if bug then WebClient.Post.try_post_with_options_async(path_api_uri,
                WebClient.Post.of_form({WebClient.Post.default_options with content = {some = data}}),
                with_result) // <= this version doesn't work, callback is called but cannot perform server->client calls
           else
             with_result(WebClient.Post.try_post_with_options(path_api_uri,
                WebClient.Post.of_form({WebClient.Post.default_options with content = {some = data}})))
                             // <= this version works, callback is called but cannot perform server->client calls
        )
      )
      payload
   )
   @private get_token(): (string, string) =
   (
     result = ((%%Recaptcha.get_challenge%%)(), (%%Recaptcha.get_response%%)())
     do (%%Recaptcha.destroy%%)()
     result
   )
}}

config = {
 private = {
   privkey = "6LeeR8QSAAAAADSnODF238nFuhfPQ13OH9sMib6o"
 }
 public  = {
   pubkey =  "6LeeR8QSAAAAANEPtPmwgSATS64g1p4qOg0fpEJH"
   theme  = {some = "red"}
 }
}

after_validation =
  | {success = _} ->
    do Log.info("Success", "success")
    Dom.transform([#status <- <>success</>])
  | {~failure}    ->
    do Log.info("Failure", "failure")
    Dom.transform([#status <- <>failure</>])

server = one_page_server("Hi", ->
  (validator, recaptcha) = Recaptcha.make(config)
  <div>
     {recaptcha}
     <button onclick={_ -> Recaptcha.validate(validator, after_validation)} > Submit </button>
     <div id=#status></div>
  </div>
)