title: CORS in Prolog not work
body: <p>I have a problem on cors in prolog. I think it not working. </p>
  
  <p>Edit #1</p>
  
  <pre><code>:- module(server,[]).
  
  :- use_module(library(http/thread_httpd)).
  :- use_module(library(http/http_dispatch)).
  :- use_module(library(http/http_cors)).
  :- use_module(library(http/http_json)).
  :- use_module(library(http/json_convert)).
  :- use_module(library(option)).
  :- use_module(library(settings)).
  :- http_handler(root(.),handle,[]).
  
  :- set_setting(http:cors, [*]).
  server(Port) :-
     http_server(http_dispatch,[port(Port)]).
  
  :- json_object
          poke(pokemon:text, move:text).
  handle(Request) :-
     format(user_output,"Request is: ~p~n",[Request]),
     format(user_output,"Request2 is: ~p~n",[]),
     cors_enable,
     http_read_json_dict(Request, DictIn,[json_object(term)]),
     format(user_output,"I'm here~n",[]),
     term_string(Pokemon,DictIn.pokemon),
     findall(poke(P,M),beat(P,M,Pokemon),L),
     prolog_to_json(L,J),
     format(user_output,"Pokemons are: ~p~n",[J]),
     DictOut=J,
     reply_json(DictOut).
  
  beat(P,M,E) :-
     pokerule:beat(P,M,E).
  </code></pre>
  
  <p>However I use ajax post to prolog server it said</p>
  
  <pre><code>XMLHttpRequest cannot load http://localhost:9999/. Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:1000' is therefore not allowed access. The response had HTTP status code 500.
  </code></pre>
  
  <p>Ajax that I use to post.</p>
  
  <pre><code>   let enemyName = this.item.text
     let data = {"pokemon":enemyName}
     $.ajax({
       url        : END_POINT,
       method     : 'post',
       contentType: 'application/json',
       dataType   : 'json',
       data       : JSON.stringify(data),
       success    : function (res) {
         console.log(res);
       },
       error :function (res) {
         console.log(res);
       } 
     })
  </code></pre>
  
  <p>How can I solve this problem?</p>
  
  <p>-Edited
  Now I fix some of my code but it still not work.</p>