hello_wiki_rest_client.opa

import stdlib.tools.markdown

uri_for_topic(topic) =
  Uri.of_absolute(
    {Uri.default_absolute with
      schema = {some = "http"} : option(string)
      domain = "localhost"
      port   = {some = 8080} : option(int)
      path   = ["_rest_", topic]
    }
  )

@publish load_source(topic) =
  match WebClient.Get.try_get(uri_for_topic(topic)) with
  | {failure = _} -> "Error, could not connect"
  | {~success} ->
      match WebClient.Result.get_class(success) with
      | {success} -> success.content
      | _         -> "Error {success.code}"
      end

@publish load_rendered(topic) =
  source = load_source(topic)
  Markdown.xhtml_of_string(Markdown.default_options, source)

@publish save_source(topic, source) =
  match WebClient.Post.try_post(uri_for_topic(topic), source) with
  | { failure = _ } ->
        {failure = "Could not reach the distant server"}
  | { success = s } ->
        match WebClient.Result.get_class(s) with
        |  {success} -> {success = load_rendered(topic)}
        |  _         -> {failure = "Error {s.code}"}
        end

remove_topic(topic) =
  _ = WebClient.Delete.try_delete(uri_for_topic(topic))
  void

edit(topic) =
  do Dom.transform([#show_messages <- <></>])
  do Dom.set_value(#edit_content, load_source(topic))
  do Dom.hide(#show_content)
  do Dom.show(#edit_content)
  do Dom.give_focus(#edit_content)
  void

save(topic) =
  match save_source(topic, Dom.get_value(#edit_content)) with
  | { ~success } ->
      do Dom.transform([#show_content <- success]);
      do Dom.hide(#edit_content);
      do Dom.show(#show_content);
      void
  | {~failure} ->
      do Dom.transform([#show_messages <- <>{failure}</>])
      void

display(topic) =
  Resource.styled_page("About {topic}", ["/resources/css.css"],
    <div id=#header><div id=#logo></div>About {topic}</div>
    <div class="show_content" id=#show_content ondblclick={_ -> edit(topic)}>{load_rendered(topic)}</>
    <div class="show_messages" id=#show_messages />
    <textarea class="edit_content" id=#edit_content style="display:none" cols="40" rows="30" onblur={_ -> save(topic)}></>
  )

rest(topic) =
  match HttpRequest.get_method() with
  | {some = method} ->
       match method with
       | {post} ->
         _ = save_source(topic, HttpRequest.get_body()?"")
         Resource.raw_status({success})
       | {delete} ->
         do remove_topic(topic)
         Resource.raw_status({success})
       | {get} ->
         Resource.source(load_source(topic), "text/plain")
       | _ ->
         Resource.raw_status({method_not_allowed})
       end
  | _ -> Resource.raw_status({bad_request})

topic_of_path(path) =
  String.capitalize(String.to_lower(List.to_string_using("", "", "::", path)))

start =
| {path = [] ... }             -> display("Hello")
| {path = ["rest" | path] ...} -> rest(topic_of_path(path))
| {~path ...}                  -> display(topic_of_path(path))

server = Server.of_bundle([@static_include_directory("resources")])
server = Server.simple_dispatch(start)