Working example for Erlang Server Interface

Question

I am trying to make Erlang's Inets mode_esi work and run some function. So, far, I did not succeed. Can someone post a minimal example of how to run Inets so that a url like http:localhost:8099/esi/my_mod:foo will invoke the method my_mod:foo/3?

Addition: I have started inets with these commands:

inets:start(),
inets:start(httpd, [{port, 8099}, {server_name, "localhost"}, {document_root, "."}, 
  {server_root, "."}, {erl_script_alias, {"/esi", [my_esi, io]}}]).

The module is:

-module(my_esi).
-export([foo/3]).
foo(Sid, Env, In) -> mod_esi:deliver(Sid, ["bla"]).

But browsing to http://localhost:8099/esi/my_esi:foo result in an error message.

Answer 1

To clarify what has already been said, I'll give a working example (from the ground up). This is to help those who came here from google, mostly because it's how I found it ;)

First, create the module:

# filename: my_esi.erl
-module(my_esi).
-export([foo/3,bar/3]).
foo(Sid, Env, In) -> mod_esi:deliver(Sid, ["foo"]).
bar(Sid, Env, In) -> mod_esi:deliver(Sid, ["bar"]).

Save it, then compile it:

erlc my_esi.erl

You'll now have my_esi.beam

Then run the shell from bash

erl

Within the shell type the following:

inets:start().
{Httpd_State,Httpd_Pid} = inets:start(httpd, [{port, 8099}, {server_name, "localhost"}, {document_root, "."}, {modules,[mod_esi]},{server_root, "."}, {erl_script_alias, {"/esi", [my_esi, io]}}]).

The important part here is:

{modules,[mod_esi]}

If you need other modules, load them by appending them to the list.

To clarify how/why:

I will first admit that it does seems a bit strange at first, and that the documentation was less helpful than I had hoped. However, I realised that:

modules()       -> [atom()]

becomes:

{modules, [mod_access, mod_esi, ..., etc.]}

Hope it helps someone :)