Method help

3rdparty/libprocess/src/help.cpp:194–322

Future<http::Response> Help::help(const http::Request& request)
{
  // Path format of the url: /help/<id>[/<name>].
  // Note that <name> may contain slashes.
  vector<string> tokens = strings::tokenize(request.url.path, "/", 3);

  Option<string> id = None();
  Option<string> name = None();

  if (tokens.size() > 1) {
    id = tokens[1];
  }

  if (tokens.size() > 2) {
    name = tokens[2];
  }

  string document;
  string references;

  if (id.isNone()) {             // http://ip:port/help
    // If the request query string has format=json, return the JSON
    // representation of the helps strings.
    //
    // NOTE: We avoided relying on the 'Accept' header to specify the
    // format because if users are hitting the endpoint from a browser
    // it is difficult to change the 'Accept' header.
    //
    // TODO(klueska): add the ability for all /help/* endpoints to be
    // returned as json, not just /help.
    if (request.url.query.get("format") == Some("json")) {
      return http::OK(jsonify(*this));
    }

    document += "## HELP\n";
    foreachkey (const string& id, helps) {
      document += "> [/" + id + "][" + id + "]\n";
      references += "[" + id + "]: help/" + id + "\n";
    }
  } else if (name.isNone()) {    // http://ip:port/help/id
    if (helps.count(id.get()) == 0) {
      return http::BadRequest(
          "No help available for '/" + id.get() + "'.\n");
    }

    document += "## `/" + id.get() + "` ##\n";
    foreachkey (const string& name, helps[id.get()]) {
      const string path = getUsagePath(id.get(), name);
      document += "> [/" + path + "][" + path + "]\n";
      references += "[" + path + "]: " + path + "\n";
    }
  } else {                       // http://ip:port/help/id/name
    if (helps.count(id.get()) == 0) {
      return http::BadRequest(
          "No help available for '/" + id.get() + "'.\n");
    } else if (helps[id.get()].count("/" + name.get()) == 0) {
      return http::BadRequest(
        "No help available for '/" + id.get() + "/" + name.get() + "'.\n");