%%% BEGIN openflax/handler/template.erl %%%
%%%
%%% openflax - Open Source web server for Erlang/OTP
%%% Copyright (c)2003 Cat's Eye Technologies.  All rights reserved.
%%%
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%%% are met:
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%%%   notice, this list of conditions and the following disclaimer.
%%%
%%%   Redistributions in binary form must reproduce the above copyright
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%%%   the documentation and/or other materials provided with the
%%%   distribution.
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%%%   contributors may be used to endorse or promote products derived
%%%   from this software without specific prior written permission.
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%% @doc Simple template generating handler for OpenFlax.
%%
%% <p>Typically this handler is swapped to from another handler.
%% This handler doesn't care about the basic resource or document,
%% and only uses the configuration settings given to it
%% to generate a simple template.</p>
%%
%% @end

-module(openflax.handler.template).
-vsn('$Id: template.erl 31 2004-04-23 07:00:11Z catseye $').
-author('cpressey@catseye.mine.nu').
-copyright('Copyright (c)2003 Cat`s Eye Technologies. All rights reserved.').

-behaviour(openflax.handler).

-export([start/1, stop/1, serve/1]). % behaviour
-export([fill_out/2]).

-import(string).

%% @spec start(conf()) -> conf()
%% @doc Initializes the templating handler.

start(Conf) ->
  openflax.conf:new().

%% @spec stop(conf()) -> conf()
%% @doc Shuts down the templating handler.

stop(Conf) ->
  Conf.

%% @spec serve(conf()) -> {response(), conf()}
%% @doc Serves a template to the user agent.

serve(Conf) ->
  Body = openflax.conf:get_string(cfg_template_body, Conf),
  Conf0 = openflax.conf:put_value(res_content_type, "text/html", Conf),
  {{content, fill_out(Body, Conf0)}, Conf0}.

%% @spec fill_out(string(), conf()) -> string()
%% @doc Replaces all <code>${tag}</code>s in the given text
%% with values from the dictionary.  The returned list is not flat.

fill_out(Text, Conf) ->
  fill_out(Text, Conf, "").

fill_out(Text, Conf, Acc) ->
  case string:str(Text, "${") of
    0 ->
      [Acc | Text];
    N ->
      M = string:chr(Text, $}),
      Pre = string:substr(Text, 1, N - 1),
      Key = list_to_atom(string:substr(Text, N + 2, M - (N + 2))),
      Post = string:substr(Text, M + 1),
      Value = openflax.conf:get_string(Key, Conf),
      fill_out(Post, Conf, [Acc, Pre | Value])
  end.

%%% END of openflax/handler/template.erl %%%