Erlang and SOAP services - A rock and a hard place

Question

My question may first of all seem to have a duplicate but i have hit something that has suprised me. Yaws Webserver comes with a complete set SOAP example, but when i tried running it as is, this is what i get:

In text form, this is what i see in the shell:

1> inets:start().
ok
2> yaws_soap_lib:call("http://www.webservicex.net/WeatherForecast.asmx?WSDL","GetWeatherByPlaceName",["Boston"]).

=ERROR REPORT==== 15-Apr-2013::20:32:11 ===
Call to tuple fun {erlsom_parse,xml2StructCallback}.
Tuple funs are deprecated and will be removed in R16. Use "fun M:F/A" instead, for example "fun erlsom_parse:xml2StructCallback/2".
(This warning will only be shown the first time a tuple fun is called.)
{error,{decoding,"Malformed: Illegal character in prolog"}}

3> yaws_soap_lib:call("http://www.webservicex.net/WeatherForecast.asmx?WSDL","GetWeatherByPlaceName",["Boston"]).
{error,{decoding,"Malformed: Illegal character in prolog"}}
4>

You could try the yaws example following this page.
Another problem, is that i have tried other SOAP libraries like detergent and erlsoap and they are either too old or completely un-usable. Most of the solutions, even yaws, mentions his dependency on erlsom i pretty think for the XML parsing. But, i can hardly use erlsom single-handedly to offer soap services.

Somebody provide some information on how i can work with soap services (both a sa client and server) in erlang, and please explain the error i am getting with yaws. I am using the latest yaws version and erlang 15B.

Answer 1

This is an ugly hack, but here's how I deal with SOAP requests:

Write a function/module that wraps the following:

1. Set up some request templates (static XMLs) and fill them up with erlydtl
2. Make a HTTP POST request (using your client of choice) with SoapAction header set.
3. Take off the important stuff from the response using erlsom

Answer 2

From the official documentation we can read the following:

Tuple funs (a two-element tuple with a module name and a function) are now officially deprecated and will be removed in R16. Use 'fun M:F/A' instead.

So, Yaws should be updated. As a workaround, you have at least two options:

1. the Detergent library
2. Or, if you don't mind using the (not so) older Erlang R15, I believe it should work, as other users reported.