src/filter_query_rewrite.cpp

   1 /* $Id: filter_query_rewrite.cpp,v 1.10 2007-01-25 14:05:54 adam Exp $
   2    Copyright (c) 2005-2007, Index Data.
   3
   4    See the LICENSE file for details
   5  */
   6
   7
   8 #include "config.hpp"
   9 #include "filter.hpp"
  10 #include "package.hpp"
  11
  12 #include "util.hpp"
  13 #include "xmlutil.hpp"
  14 #include "filter_query_rewrite.hpp"
  15
  16 #include <yaz/zgdu.h>
  17 #include <yaz/xmlquery.h>
  18 #include <yaz/diagbib1.h>
  19
  20 #include <libxslt/xsltutils.h>
  21 #include <libxslt/transform.h>
  22
  23 namespace mp = metaproxy_1;
  24 namespace yf = mp::filter;
  25
  26 namespace metaproxy_1 {
  27     namespace filter {
  28         class QueryRewrite::Rep {
  29         public:
  30             Rep();
  31             ~Rep();
  32             void process(mp::Package &package) const;
  33             void configure(const xmlNode * ptr);
  34         private:
  35             xsltStylesheetPtr m_stylesheet;
  36         };
  37     }
  38 }
  39
  40 yf::QueryRewrite::Rep::Rep()
  41 {
  42     m_stylesheet = 0;
  43 }
  44
  45 yf::QueryRewrite::Rep::~Rep()
  46 {
  47     if (m_stylesheet)
  48         xsltFreeStylesheet(m_stylesheet);
  49 }
  50
  51 yf::QueryRewrite::QueryRewrite() : m_p(new Rep)
  52 {
  53 }
  54
  55 yf::QueryRewrite::~QueryRewrite()
  56 {  // must have a destructor because of boost::scoped_ptr
  57 }
  58
  59 void yf::QueryRewrite::process(mp::Package &package) const
  60 {
  61     m_p->process(package);
  62 }
  63
  64 void mp::filter::QueryRewrite::configure(const xmlNode *ptr)
  65 {
  66     m_p->configure(ptr);
  67 }
  68
  69 void yf::QueryRewrite::Rep::process(mp::Package &package) const
  70 {
  71     Z_GDU *gdu = package.request().get();
  72
  73     if (gdu && gdu->which == Z_GDU_Z3950)
  74     {
  75         Z_APDU *apdu_req = gdu->u.z3950;
  76         if (apdu_req->which == Z_APDU_searchRequest)
  77         {
  78             int error_code = 0;
  79             const char *addinfo = 0;
  80             mp::odr odr;
  81             Z_SearchRequest *req = apdu_req->u.searchRequest;
  82
  83             xmlDocPtr doc_input = 0;
  84             yaz_query2xml(req->query, &doc_input);
  85
  86             if (!doc_input)
  87             {
  88                 error_code = YAZ_BIB1_MALFORMED_QUERY;
  89                 addinfo = "converion from Query to XML failed";
  90             }
  91             else
  92             {
  93                 if (m_stylesheet)
  94                 {
  95                     xmlDocPtr doc_res = xsltApplyStylesheet(m_stylesheet,
  96                                                             doc_input, 0);
  97                     if (!doc_res)
  98                     {
  99                         error_code = YAZ_BIB1_MALFORMED_QUERY;
 100                         addinfo = "XSLT transform failed for query";
 101                     }
 102                     else
 103                     {
 104                         const xmlNode *root_element = xmlDocGetRootElement(doc_res);
 105                         yaz_xml2query(root_element, &req->query, odr,
 106                                       &error_code, &addinfo);
 107                         xmlFreeDoc(doc_res);
 108                     }
 109                 }
 110                 xmlFreeDoc(doc_input);
 111             }
 112             package.request() = gdu;
 113             if (error_code)
 114             {
 115                 Z_APDU *f_apdu =
 116                     odr.create_searchResponse(apdu_req, error_code, addinfo);
 117                 package.response() = f_apdu;
 118                 return;
 119             }
 120         }
 121     }
 122     package.move();
 123 }
 124
 125 void mp::filter::QueryRewrite::Rep::configure(const xmlNode *ptr)
 126 {
 127     for (ptr = ptr->children; ptr; ptr = ptr->next)
 128     {
 129         if (ptr->type != XML_ELEMENT_NODE)
 130             continue;
 131
 132         if (mp::xml::check_element_mp(ptr, "xslt"))
 133         {
 134             if (m_stylesheet)
 135             {
 136                 throw mp::filter::FilterException
 137                     ("Only one xslt element allowed in query_rewrite filter");
 138             }
 139
 140             std::string fname;// = mp::xml::get_text(ptr);
 141
 142             for (struct _xmlAttr *attr = ptr->properties;
 143                  attr; attr = attr->next)
 144             {
 145                 mp::xml::check_attribute(attr, "", "stylesheet");
 146                 fname = mp::xml::get_text(attr);
 147             }
 148
 149             if (0 == fname.size())
 150                 throw mp::filter::FilterException
 151                     ("Attribute <xslt stylesheet=\""
 152                      + fname
 153                      + "\"> needs XSLT stylesheet path content"
 154                      + " in query_rewrite filter");
 155
 156             m_stylesheet = xsltParseStylesheetFile(BAD_CAST fname.c_str());
 157             if (!m_stylesheet)
 158             {
 159                 throw mp::filter::FilterException
 160                     ("Failed to read XSLT stylesheet '"
 161                      + fname
 162                      + "' in query_rewrite filter");
 163             }
 164         }
 165         else
 166         {
 167             throw mp::filter::FilterException
 168                 ("Bad element "
 169                  + std::string((const char *) ptr->name)
 170                  + " in query_rewrite filter");
 171         }
 172     }
 173 }
 174
 175 static mp::filter::Base* filter_creator()
 176 {
 177     return new mp::filter::QueryRewrite;
 178 }
 179
 180 extern "C" {
 181     struct metaproxy_1_filter_struct metaproxy_1_filter_query_rewrite = {
 182         0,
 183         "query_rewrite",
 184         filter_creator
 185     };
 186 }
 187
 188 /*
 189  * Local variables:
 190  * c-basic-offset: 4
 191  * indent-tabs-mode: nil
 192  * c-file-style: "stroustrup"
 193  * End:
 194  * vim: shiftwidth=4 tabstop=8 expandtab
 195  */