src/xslt_aux.h

   1 /*
   2   Copyright (c) 2008 Instituto Nokia de Tecnologia
   3   All rights reserved.
   4
   5   Redistribution and use in source and binary forms, with or without modification,
   6   are permitted provided that the following conditions are met:
   7
   8   * Redistributions of source code must retain the above copyright notice,
   9   this list of conditions and the following disclaimer.
  10   * Redistributions in binary form must reproduce the above copyright notice,
  11   this list of conditions and the following disclaimer in the documentation
  12   and/or other materials provided with the distribution.
  13   * Neither the name of the INdT nor the names of its contributors
  14   may be used to endorse or promote products derived from this software
  15   without specific prior written permission.
  16
  17   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  18   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20   ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  21   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  22   CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  23   SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  24   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  25   CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  26   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  27   POSSIBILITY OF SUCH DAMAGE.
  28 */
  29 /**
  30  * @file   xslt_aux.h
  31  * @author Adenilson Cavalcanti da Silva <adenilson.silva@indt.org.br>
  32  * @date   Mon Aug 25 15:50:20 2008
  33  *
  34  * @brief  A XSLT helper module, converts a XML doc to another format
  35  * using a xslt file.
  36  *
  37  * Depends on libxml and libxslt.
  38  *
  39  * \todo:
  40  * - doxygen comments about use
  41  * - move code to a '.c' file or make functions static
  42  * - make 'xslt_resources' an abstract type
  43  *
  44  */
  45
  46 #ifndef __XSLT_AUX__
  47 #define __XSLT_AUX__
  48
  49 #include <libxml/HTMLtree.h>
  50 #include <libxml/catalog.h>
  51 #include <libxml/debugXML.h>
  52 #include <libxml/xinclude.h>
  53 #include <libxml/xmlIO.h>
  54 #include <libxml/xmlmemory.h>
  55 #include <libxslt/transform.h>
  56 #include <libxslt/xslt.h>
  57 #include <libxslt/xsltInternals.h>
  58 #include <libxslt/xsltutils.h>
  59 #include <string.h>
  60
  61 struct xslt_resources {
  62         xmlDocPtr output;
  63         xmlDocPtr doc;
  64         xsltStylesheetPtr cur;
  65         xmlChar *xml_str;
  66         int length;
  67         char init_flag;
  68 };
  69
  70 struct xslt_resources *xslt_new(void)
  71 {
  72         struct xslt_resources *result;
  73         result = (struct xslt_resources *)malloc(sizeof(struct xslt_resources));
  74         if (result)
  75                 memset(result, 0, sizeof(struct xslt_resources));
  76
  77         return result;
  78 }
  79
  80 int xslt_initialize(struct xslt_resources *ctx, const char *stylesheet_path)
  81 {
  82         int result = -1;
  83         if (!stylesheet_path || !ctx)
  84                 goto exit;
  85
  86         xmlSubstituteEntitiesDefault(1);
  87         xmlLoadExtDtdDefaultValue = 1;
  88
  89         if (ctx->cur)
  90                 xsltFreeStylesheet(ctx->cur);
  91
  92         ctx->cur = xsltParseStylesheetFile((const xmlChar *)stylesheet_path);
  93         if (!ctx->cur) {
  94                 fprintf(stderr, "Cannot create XSLT context!\n");
  95                 goto exit;
  96         }
  97
  98         result = 0;
  99         ctx->init_flag = 1;
 100 exit:
 101         return result;
 102 }
 103
 104 int xslt_transform(struct xslt_resources *ctx, const char *document)
 105 {
 106         int result = -1;
 107         if (!ctx || !document)
 108                 goto exit;
 109
 110         if (ctx->doc)
 111                 xmlFreeDoc(ctx->doc);
 112         if (ctx->output)
 113                 xmlFreeDoc(ctx->output);
 114         ctx->output = NULL;
 115
 116         ctx->doc = xmlReadMemory(document, strlen(document), "noname.xml",
 117                                  NULL, 0);
 118         if (!ctx->doc) {
 119                 fprintf(stderr, "Cannot create document with "
 120                         "entry!\n");
 121                 goto cleanup;
 122         }
 123
 124         ctx->output = xsltApplyStylesheet(ctx->cur, ctx->doc, NULL);
 125         if (!ctx->output) {
 126                 fprintf(stderr, "Cannot create document with "
 127                         "output!\n");
 128                 goto cleanup;
 129         }
 130
 131         if (ctx->xml_str) {
 132                 xmlFree(ctx->xml_str);
 133                 ctx->xml_str = NULL;
 134         }
 135         xmlDocDumpMemory(ctx->output, &(ctx->xml_str), &(ctx->length));
 136
 137         result = 0;
 138
 139 cleanup:
 140         if (ctx->doc)
 141                 xmlFreeDoc(ctx->doc);
 142         ctx->doc = NULL;
 143
 144         if (ctx->output)
 145                 xmlFreeDoc(ctx->output);
 146         ctx->output = NULL;
 147 exit:
 148
 149         return result;
 150 }
 151
 152 void xslt_delete(struct xslt_resources *ctx)
 153 {
 154         if (!ctx)
 155                 return;
 156
 157         /* TODO: 'output' is pointing to a non null value (probably an
 158          * overflow in some other place) even when not initialized.
 159          * It happens just after all clients are disconnected.
 160          * I must investigate it further, for while the flag is a work
 161          * around to stop msync to crash.
 162          */
 163 /*      fprintf(stderr, "\ndoc: %x\tout: %x\txml: %x\tcur: %x\n\n", */
 164 /*              ctx->doc, ctx->output, ctx->xml_str, ctx->cur); */
 165
 166         if (!ctx->init_flag)
 167                 goto exit;
 168
 169
 170         if (ctx->doc)
 171                 xmlFreeDoc(ctx->doc);
 172         if (ctx->output)
 173                 xmlFreeDoc(ctx->output);
 174         if (ctx->xml_str)
 175                 xmlFree(ctx->xml_str);
 176         if (ctx->cur) {
 177                 xsltFreeStylesheet(ctx->cur);
 178                 xsltCleanupGlobals();
 179                 xmlCleanupParser();
 180         }
 181
 182 exit:
 183
 184         free(ctx);
 185 }
 186
 187 #endif