src/filter_query_rewrite.cpp

   1 /* $Id: filter_query_rewrite.cpp,v 1.5 2006-03-16 09:38:33 adam Exp $
   2    Copyright (c) 2005, Index Data.
   3
   4 %LICENSE%
   5  */
   6
   7
   8 #include "config.hpp"
   9 #include "filter.hpp"
  10 #include "package.hpp"
  11
  12 #include "util.hpp"
  13 #include "filter_query_rewrite.hpp"
  14
  15 #include <yaz/zgdu.h>
  16 #include <yaz/xmlquery.h>
  17 #include <yaz/diagbib1.h>
  18
  19 #include <libxslt/xsltutils.h>
  20 #include <libxslt/transform.h>
  21
  22 namespace yf = yp2::filter;
  23
  24 namespace yp2 {
  25     namespace filter {
  26         class QueryRewrite::Rep {
  27         public:
  28             Rep();
  29             ~Rep();
  30             void process(yp2::Package &package) const;
  31             void configure(const xmlNode * ptr);
  32         private:
  33             xsltStylesheetPtr m_stylesheet;
  34         };
  35     }
  36 }
  37
  38 yf::QueryRewrite::Rep::Rep()
  39 {
  40     m_stylesheet = 0;
  41 }
  42
  43 yf::QueryRewrite::Rep::~Rep()
  44 {
  45     if (m_stylesheet)
  46         xsltFreeStylesheet(m_stylesheet);
  47 }
  48
  49 yf::QueryRewrite::QueryRewrite() : m_p(new Rep)
  50 {
  51 }
  52
  53 yf::QueryRewrite::~QueryRewrite()
  54 {  // must have a destructor because of boost::scoped_ptr
  55 }
  56
  57 void yf::QueryRewrite::process(yp2::Package &package) const
  58 {
  59     m_p->process(package);
  60 }
  61
  62 void yp2::filter::QueryRewrite::configure(const xmlNode *ptr)
  63 {
  64     m_p->configure(ptr);
  65 }
  66
  67 void yf::QueryRewrite::Rep::process(yp2::Package &package) const
  68 {
  69     Z_GDU *gdu = package.request().get();
  70
  71     if (gdu && gdu->which == Z_GDU_Z3950)
  72     {
  73         Z_APDU *apdu_req = gdu->u.z3950;
  74         if (apdu_req->which == Z_APDU_searchRequest)
  75         {
  76             int error_code = 0;
  77             const char *addinfo = 0;
  78             yp2::odr odr;
  79             Z_SearchRequest *req = apdu_req->u.searchRequest;
  80
  81             xmlDocPtr doc_input = 0;
  82             yaz_query2xml(req->query, &doc_input);
  83
  84             if (!doc_input)
  85             {
  86                 error_code = YAZ_BIB1_MALFORMED_QUERY;
  87                 addinfo = "converion from Query to XML failed";
  88             }
  89             else
  90             {
  91                 if (m_stylesheet)
  92                 {
  93                     xmlDocPtr doc_res = xsltApplyStylesheet(m_stylesheet,
  94                                                             doc_input, 0);
  95                     if (!doc_res)
  96                     {
  97                         error_code = YAZ_BIB1_MALFORMED_QUERY;
  98                         addinfo = "XSLT transform failed for query";
  99                     }
 100                     else
 101                     {
 102                         const xmlNode *root_element = xmlDocGetRootElement(doc_res);
 103                         yaz_xml2query(root_element, &req->query, odr,
 104                                       &error_code, &addinfo);
 105                         xmlFreeDoc(doc_res);
 106                     }
 107                 }
 108                 xmlFreeDoc(doc_input);
 109             }
 110             package.request() = gdu;
 111             if (error_code)
 112             {
 113                 Z_APDU *f_apdu =
 114                     odr.create_searchResponse(apdu_req, error_code, addinfo);
 115                 package.response() = f_apdu;
 116                 return;
 117             }
 118         }
 119     }
 120     package.move();
 121 }
 122
 123 void yp2::filter::QueryRewrite::Rep::configure(const xmlNode *ptr)
 124 {
 125     for (ptr = ptr->children; ptr; ptr = ptr->next)
 126     {
 127         if (ptr->type != XML_ELEMENT_NODE)
 128             continue;
 129         if (!strcmp((const char *) ptr->name, "xslt"))
 130         {
 131             if (m_stylesheet)
 132             {
 133                 throw yp2::filter::FilterException
 134                     ("Only one xslt element allowed in query_rewrite filter");
 135             }
 136
 137             std::string fname = yp2::xml::get_text(ptr);
 138             m_stylesheet = xsltParseStylesheetFile(BAD_CAST fname.c_str());
 139             if (!m_stylesheet)
 140             {
 141                 throw yp2::filter::FilterException
 142                     ("Failed to read stylesheet "
 143                      + fname
 144                      + " in query_rewrite filter");
 145             }
 146         }
 147         else
 148         {
 149             throw yp2::filter::FilterException
 150                 ("Bad element "
 151                  + std::string((const char *) ptr->name)
 152                  + " in query_rewrite filter");
 153         }
 154     }
 155 }
 156
 157 static yp2::filter::Base* filter_creator()
 158 {
 159     return new yp2::filter::QueryRewrite;
 160 }
 161
 162 extern "C" {
 163     struct yp2_filter_struct yp2_filter_query_rewrite = {
 164         0,
 165         "query-rewrite",
 166         filter_creator
 167     };
 168 }
 169
 170 /*
 171  * Local variables:
 172  * c-basic-offset: 4
 173  * indent-tabs-mode: nil
 174  * c-file-style: "stroustrup"
 175  * End:
 176  * vim: shiftwidth=4 tabstop=8 expandtab
 177  */