ACTION adaptor: SOAP

This is the ACTION adaptor for local SOAP calls. It allows workflow processes to do arbitrary "SOAP stuff", meaning among other things that you can use it to provide a permissions layer on any program you want to run from the command line.

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include "xmlapi.h"
#include "../wftk_session.h"
#include "../wftk_internals.h"

There are no surprises in the now-standard admin portion of the adaptor.

static char *names[] = 
{
   "init",
   "free",
   "info",
   "do"
};

XML * ACTION_soap_init (WFTK_ADAPTOR * ad, va_list args);
XML * ACTION_soap_free (WFTK_ADAPTOR * ad, va_list args);
XML * ACTION_soap_info (WFTK_ADAPTOR * ad, va_list args);
XML * ACTION_soap_do (WFTK_ADAPTOR * ad, va_list args);

static WFTK_API_FUNC vtab[] = 
{
   ACTION_soap_init,
   ACTION_soap_free,
   ACTION_soap_info,
   ACTION_soap_do
};

static struct wftk_adaptor_info _ACTION_soap_info =
{
   4,
   names,
   vtab
};
struct wftk_adaptor_info * ACTION_soap_get_info ()
{
   return & _ACTION_soap_info;
}
XML * ACTION_soap_init (WFTK_ADAPTOR * ad, va_list args) {
   xml_set (ad->parms, "spec", "wftk");
   return (XML *) 0;
}
XML * ACTION_soap_free (WFTK_ADAPTOR * ad, va_list args) { return (XML *) 0; }
XML * ACTION_soap_info (WFTK_ADAPTOR * ad, va_list args) {
   XML * info;

   info = xml_create ("info");
   xml_set (info, "type", "action");
   xml_set (info, "name", "soap");
   xml_set (info, "ver", "1.0.0");
   xml_set (info, "compiled", __TIME__ " " __DATE__);
   xml_set (info, "author", "Michael Roberts");
   xml_set (info, "contact", "wftk@vivtek.com");
   xml_set (info, "extra_functions", "0");

   return (info);
}

As with all the action adaptors, all the action happens in the "do" function. In the case of the SOAP adaptor, since the heavy lifting is done by the HTTP adaptor and libcurl, all we really have to do is to preprocess the action in order to construct a valid SOAP envelope to write to the POST content. After the HTTP adaptor is called, we then have to deconstruct the answering XML from the remote server, and distribute data as appropriate.

XML * ACTION_soap_do  (WFTK_ADAPTOR * ad, va_list args)
{
   XML * action = (XML *) 0;
   XML * datasheet;
   XML * soap_body;
   XML * soap_env;
   XML * soap_request;
   XML * soap_parm;
   XML * mark;
   char * value;
   char * soap_str;
   XML * http_action;
   XML * http_content;
   WFTK_ADAPTOR * http_ad;
   XML * soap_return;
   XML * result_spec;

   if (args) action = va_arg (args, XML *);
   if (!action) {
      xml_set (ad->parms, "error", "No action given.");
      return (XML *) 0;
   }
   datasheet = va_arg (args, XML *);

   if (!*xml_attrval (action, "server")) {
      xml_set (ad->parms, "error", "No server specified in action.");
      return NULL;
   }

   http_ad = wftk_get_adaptor (ad->session, ACTION, "http");
   if (!http_ad) {
      xml_set (ad->parms, "error", "Unable to initialize libcurl");
      return NULL;
   }

   /* All right, everything's hunky-dory; down to business. */
   /* Build SOAP request. */
   soap_env = xml_create ("SOAP-ENV:Envelope");
   xml_set (soap_env, "SOAP-ENV:encodingStyle", "http://schemas.xmlsoap.org/soap/encoding/");
   xml_set (soap_env, "xmlns:xsd",              "http://www.w3.org/1999/XMLSchema");
   xml_set (soap_env, "xmlns:SOAP-ENV",         "http://schemas.xmlsoap.org/soap/envelope/");
   xml_set (soap_env, "xmlns:xsi",              "http://www.w3.org/1999/XMLSchema-instance");
   xml_set (soap_env, "xmlns:SOAP-ENC",         "http://schemas.xmlsoap.org/soap/encoding/");

   soap_body = xml_create ("SOAP-ENV:Body");
   xml_append_pretty (soap_env, soap_body);

   soap_request = xml_create (xml_attrval (action, "function"));
   xml_append_pretty (soap_body, soap_request);
   xml_set (soap_request, "SOAP-ENC:root", "1");

   mark = xml_firstelem (action);
   while (mark) {
      if (xml_is (mark, "parm")) {
         soap_parm = xml_create (xml_attrval (mark, "name"));
         xml_set (soap_parm, "xsi:type", *xml_attrval (mark, "xsi:type") ? xml_attrval (mark, "xsi:type") : "xsd:string");
         if (*xml_attrval (mark, "field")) {
            value = xmlobj_get (datasheet, NULL, xml_attrval (mark, "field"));
         } else {
            value = xmlobj_get_direct (mark);
         }
         xml_append (soap_parm, xml_createtext_nodup (value));

         xml_append_pretty (soap_request, soap_parm);
      }
      mark = xml_nextelem (mark);
   }

   soap_str = xml_string (soap_env);
   xml_free (soap_env);

   /* Build HTTP request. */
   http_action = xml_create ("action");
   xml_set (http_action, "url", xml_attrval (action, "server"));
   xml_set (http_action, "method", "post");

   http_content = xml_createtext ("\n");
   xml_textcat (http_content, soap_str);
   xml_textcat (http_content, "\n");
   mark = xml_create ("content");
   xml_append (mark, http_content);
   xml_append_pretty (http_action, mark);
   free (soap_str);

   /* Perform request. */
   wftk_call_adaptor (http_ad, "do", http_action, datasheet);
   if (!strcmp (xml_attrval (http_action, "http-retcode"), "500")) {
      xml_set (ad->parms, "error", "Remote server experienced server error (code: 500)");
   }


   result_spec = xml_loc (action, ".result");
   if (result_spec) {
      /* Interpret results. */
      soap_str = xml_stringcontenthtml (xml_loc (http_action, ".result"));
      soap_return = xml_parse (soap_str);
      free (soap_str);
      xml_free (http_action);

      soap_body = xml_firstelem (soap_return); /* TODO: do we care about multiple bodies?  At the moment, no.*/

      soap_body = xml_firstelem (soap_body); /* TODO: how about multiple responses in one body?  Same answer at present. */

      if (*xml_attrval (result_spec, "field")) {
         mark = xml_firstelem (soap_body); /* First approximation: take the first value in the response and run with it. */
         value = xml_stringcontent (mark);
         xmlobj_set_nodup (datasheet, NULL, xml_attrval (result_spec, "field"), value);
      }

      xml_append_pretty (result_spec, xml_copy (soap_body));
      xml_free (soap_return);
   }
}

This code and documentation are released under the terms of the GNU license. They are copyright (c) 2003, Vivtek. All rights reserved except those explicitly granted under the terms of the GNU license. This presentation was prepared with LPML. Try literate programming. You'll like it.