erlang - How do I start yaws to run in embedded mode? -

i've spent several hours trying troubleshoot issue using yaws documentation , web searches. existing threads here haven't helped me.

i new erlang , trying run yaws in embedded mode using sample code provided on http://yaws.hyber.org/embed.yaws. missing because cannot work. have 4 files:

ybed.app

{application, ybed_app,  [   {description, "yaws embedded application test"},   {vsn, "0.1.0"},   {registered, []},   {applications, [kernel, stdlib, yaws]},   {mod, {ybed_app, []}},   {env, []}  ]}. 

ybed_app.erl

-module(ybed_app). -behaviour(application).  %% application callbacks -export([start/2,          stop/1]).  start(_starttype, _startargs) ->     case ybed_sup:start_link() of         {ok, pid} ->             {ok, pid};         other ->             {error, other}     end.  stop(_state) ->     ok. 

ybed_sup.erl

-module(ybed_sup). -behaviour(supervisor).  %% api -export([start_link/0]).  %% supervisor callbacks -export([init/1]).  start_link() ->     supervisor:start_link({local, ?module}, ?module, []).  init([]) ->     ybed = {ybed, {ybed,start,[]},             permanent,2000,worker,[ybed]},     {ok,{{one_for_all,0,1}, [ybed]}}. 

ybed.erl

-module(ybed). -compile(export_all).  start() ->     {ok, spawn(?module, run, [])}.  run() ->     id = "embedded",     gconflist = [{id, id}],     docroot = "/tmp",     sconflist = [{port, 8000},                  {servername, "foobar"},                  {listen, {127,0,0,1}},                  {docroot, docroot}],     {ok, sclist, gc, childspecs} =         yaws_api:embedded_start_conf(docroot, sconflist, gconflist, id),     [supervisor:start_child(ybed_sup, ch) || ch <- childspecs],     yaws_api:setconf(gc, sclist),      {ok, self()}. 

when compile (successfully) , try start application, return value:

{error,{not_loaded,yaws}} 

when try run compiled ybed.erl, ybed:run(), get:

** exception error: undefined function yaws_api:embedded_start_conf/4      in function  ybed:run/0 (src/ybed.erl, line 16) 

if start yaws before start application, still doesn't work.

i not trying build releases yet, compile , test yaws in embedded mode. can tell me i'm missing?

thanks in advance

when error

** exception error: undefined function yaws_api:embedded_start_conf/4      in function  ybed:run/0 (src/ybed.erl, line 16) 

you don't have yaws_api.beam in code server search path. start erl proper -pa argument or call code:add_patha/1 in application initialization if not planning use embedded mode.

btw there neat way how start yaws under own supervisor described in yaws documentation without complete code here go in 1 module , neat debugging resource , preparation rest servicing.

-module(ybed_yaws).  -behaviour(supervisor).  -include_lib("yaws/include/yaws_api.hrl").  %% api -export([start_link/0]).  %% supervisor callbacks -export([init/1]).  %% internal functions export -export([init_yaws/1, out/1]).  %%%=================================================================== %%% defaults %%%===================================================================  default_global() ->     #{id => "yaws", logdir => "log"}.  default_server() ->     #{port => 9900,       listen => {0,0,0,0},       docroot => "www",       appmods => [{"/", ?module}]}.  %%%=================================================================== %%% api functions %%%===================================================================  start_link() ->     supervisor:start_link(?module, []).  %%%=================================================================== %%% supervisor callbacks %%%===================================================================  init([]) ->     {ok,      {{one_for_all, 0, 1},       [#{id => init_yaws,          start => {?module, init_yaws, [self()]},          restart => transient}]      }}.  %%%=================================================================== %%% internal functions %%%===================================================================  init_yaws(sup) ->     {ok, proc_lib:spawn_link(fun() -> config(sup) end)}.  ensure_dir(dir) ->     {ok, app} = application:get_application(),     d = filename:join([code:priv_dir(app), dir])     filelib:ensure_dir(filename:join([d, "foo"])),     d.  config(supervisor) ->     #{id := id} = gcmap = default_global(),     #{docroot := dr} = scmap = default_server(),     docroot = ensure_dir(dr),     {ok, sc, gc, childspecs} =         yaws_api:embedded_start_conf(           docroot,           maps:to_list(scmap#{docroot => docroot}),           maps:to_list(gcmap),           id),     [supervisor:start_child(supervisor, ch) || ch <- childspecs],     yaws_api:setconf(gc, sc),     ok.  -compile({inline, [h/1, f/2]}). h(a) when is_atom(a) -> h(atom_to_binary(a, latin1)); h(s) -> yaws_api:htmlize(s).  f(fmt, args) -> yaws_api:f(fmt, args).  box(str) ->     {'div',[{class,"box"}],      {pre, [], h(str)}}.  out(a) ->     pathstring = case a#arg.pathinfo of                undefined -> "";                p -> p            end,     path = string:tokens(pathstring, "/"),     method = a#arg.req#http_request.method,     out(a, method, path).  out(a, method, path) ->     {ehtml,      {html, [],       [{head},        {body, [],         [          {h5, [], "paths:"},          {hr},          box(f("method = ~p~n"                "path = ~p~n"                "a#arg.querydata = ~p~n",                [method,                 path,                 a#arg.querydata])),          {h5, [], "headers:"},          {hr},          {ol, [], yaws_api:reformat_header(                     a#arg.headers,                     fun(h, v)->                             {li, [], [h(h), ": ", {code, [], h(v)}]}                     end                    )}         ]}       ]}     }. 

note way how yaws initialised in otp compliant transient process without gen_server.

add {yaws, [{embedded, true}]} .config file keep yaws application common services starting. work without not embedded.