xml.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2008, Eliel C. Sardanons (LU1ALY) <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief XML abstraction layer
 *
 * \author Eliel C. Sardanons (LU1ALY) <[email protected]>
 */

/*** MODULEINFO
   <support_level>core</support_level>
 ***/

#include "asterisk.h"
#include "asterisk/xml.h"
#include "asterisk/logger.h"
#include "asterisk/utils.h"
#include "asterisk/autoconfig.h"

#if defined(HAVE_LIBXML2)
#include <libxml/parser.h>
#include <libxml/tree.h>
#include <libxml/xinclude.h>
#include <libxml/xpath.h>
/* libxml2 ast_xml implementation. */
#ifdef HAVE_LIBXSLT
   #include <libxslt/xsltInternals.h>
   #include <libxslt/transform.h>
#endif /* HAVE_LIBXSLT */


int ast_xml_init(void)
{
   LIBXML_TEST_VERSION

   return 0;
}

int ast_xml_finish(void)
{
   xmlCleanupParser();
#ifdef HAVE_LIBXSLT_CLEANUP
   xsltCleanupGlobals();
#endif

   return 0;
}

struct ast_xml_doc *ast_xml_open(char *filename)
{
   xmlDoc *doc;

   if (!filename) {
      return NULL;
   }

   doc = xmlReadFile(filename, NULL, XML_PARSE_RECOVER);
   if (!doc) {
      return NULL;
   }

   /* process xinclude elements. */
   if (xmlXIncludeProcess(doc) < 0) {
      xmlFreeDoc(doc);
      return NULL;
   }

#ifdef HAVE_LIBXSLT
   {
      xsltStylesheetPtr xslt = xsltLoadStylesheetPI(doc);
      if (xslt) {
         xmlDocPtr tmpdoc = xsltApplyStylesheet(xslt, doc, NULL);
         xsltFreeStylesheet(xslt);
         xmlFreeDoc(doc);
         if (!tmpdoc) {
            return NULL;
         }
         doc = tmpdoc;
      }
   }
#else /* no HAVE_LIBXSLT */
   ast_log(LOG_NOTICE, "XSLT support not found. XML documentation may be incomplete.\n");
#endif /* HAVE_LIBXSLT */

   /* Optimize for XPath */
   xmlXPathOrderDocElems(doc);

   return (struct ast_xml_doc *) doc;
}

struct ast_xml_doc *ast_xml_new(void)
{
   xmlDoc *doc;

   doc = xmlNewDoc((const xmlChar *) "1.0");
   return (struct ast_xml_doc *) doc;
}

struct ast_xml_node *ast_xml_new_node(const char *name)
{
   xmlNode *node;
   if (!name) {
      return NULL;
   }

   node = xmlNewNode(NULL, (const xmlChar *) name);

   return (struct ast_xml_node *) node;
}

struct ast_xml_node *ast_xml_new_child(struct ast_xml_node *parent, const char *child_name)
{
   xmlNode *child;

   if (!parent || !child_name) {
      return NULL;
   }

   child = xmlNewChild((xmlNode *) parent, NULL, (const xmlChar *) child_name, NULL);
   return (struct ast_xml_node *) child;
}

struct ast_xml_node *ast_xml_add_child(struct ast_xml_node *parent, struct ast_xml_node *child)
{
   if (!parent || !child) {
      return NULL;
   }
   return (struct ast_xml_node *) xmlAddChild((xmlNode *) parent, (xmlNode *) child);
}

struct ast_xml_node *ast_xml_add_child_list(struct ast_xml_node *parent, struct ast_xml_node *child)
{
   if (!parent || !child) {
      return NULL;
   }
   return (struct ast_xml_node *) xmlAddChildList((xmlNode *) parent, (xmlNode *) child);
}

struct ast_xml_node *ast_xml_copy_node_list(struct ast_xml_node *list)
{
   if (!list) {
      return NULL;
   }
   return (struct ast_xml_node *) xmlCopyNodeList((xmlNode *) list);
}

struct ast_xml_doc *ast_xml_read_memory(char *buffer, size_t size)
{
   xmlDoc *doc;

   if (!buffer) {
      return NULL;
   }

   if (!(doc = xmlParseMemory(buffer, (int) size))) {
      /* process xinclude elements. */
      if (xmlXIncludeProcess(doc) < 0) {
         xmlFreeDoc(doc);
         return NULL;
      }
   }

   return (struct ast_xml_doc *) doc;
}

void ast_xml_close(struct ast_xml_doc *doc)
{
   if (!doc) {
      return;
   }

   xmlFreeDoc((xmlDoc *) doc);
   doc = NULL;
}

void ast_xml_set_root(struct ast_xml_doc *doc, struct ast_xml_node *node)
{
   if (!doc || !node) {
      return;
   }

   xmlDocSetRootElement((xmlDoc *) doc, (xmlNode *) node);
}

struct ast_xml_node *ast_xml_get_root(struct ast_xml_doc *doc)
{
   xmlNode *root_node;

   if (!doc) {
      return NULL;
   }

   root_node = xmlDocGetRootElement((xmlDoc *) doc);

   return (struct ast_xml_node *) root_node;
}

void ast_xml_free_node(struct ast_xml_node *node)
{
   if (!node) {
      return;
   }

   xmlFreeNode((xmlNode *) node);
   node = NULL;
}

void ast_xml_free_attr(const char *attribute)
{
   if (attribute) {
      xmlFree((char *) attribute);
   }
}

void ast_xml_free_text(const char *text)
{
   if (text) {
      xmlFree((char *) text);
   }
}

const char *ast_xml_get_attribute(struct ast_xml_node *node, const char *attrname)
{
   xmlChar *attrvalue;

   if (!node) {
      return NULL;
   }

   if (!attrname) {
      return NULL;
   }

   attrvalue = xmlGetProp((xmlNode *) node, (xmlChar *) attrname);

   return (const char *) attrvalue;
}

int ast_xml_set_attribute(struct ast_xml_node *node, const char *name, const char *value)
{
   if (!name || !value) {
      return -1;
   }

   if (!xmlSetProp((xmlNode *) node, (xmlChar *) name, (xmlChar *) value)) {
      return -1;
   }

   return 0;
}

struct ast_xml_node *ast_xml_find_element(struct ast_xml_node *root_node, const char *name, const char *attrname, const char *attrvalue)
{
   struct ast_xml_node *cur;
   const char *attr;

   if (!root_node) {
      return NULL;
   }

   for (cur = root_node; cur; cur = ast_xml_node_get_next(cur)) {
      /* Check if the name matchs */
      if (strcmp(ast_xml_node_get_name(cur), name)) {
         continue;
      }
      /* We need to check for a specific attribute name? */
      if (!attrname || !attrvalue) {
         return cur;
      }
      /* Get the attribute, we need to compare it. */
      if ((attr = ast_xml_get_attribute(cur, attrname))) {
         /* does attribute name/value matches? */
         if (!strcmp(attr, attrvalue)) {
            ast_xml_free_attr(attr);
            return cur;
         }
         ast_xml_free_attr(attr);
      }
   }

   return NULL;
}

struct ast_xml_doc *ast_xml_get_doc(struct ast_xml_node *node)
{
   if (!node) {
      return NULL;
   }

   return (struct ast_xml_doc *) ((xmlNode *)node)->doc;
}

struct ast_xml_ns *ast_xml_find_namespace(struct ast_xml_doc *doc, struct ast_xml_node *node, const char *ns_name) {
   xmlNsPtr ns = xmlSearchNs((xmlDocPtr) doc, (xmlNodePtr) node, (xmlChar *) ns_name);
   return (struct ast_xml_ns *) ns;
}

const char *ast_xml_get_ns_href(struct ast_xml_ns *ns)
{
   return (const char *) ((xmlNsPtr) ns)->href;
}

const char *ast_xml_get_text(struct ast_xml_node *node)
{
   if (!node) {
      return NULL;
   }

   return (const char *) xmlNodeGetContent((xmlNode *) node);
}

void ast_xml_set_text(struct ast_xml_node *node, const char *content)
{
   if (!node || !content) {
      return;
   }

   xmlNodeSetContent((xmlNode *) node, (const xmlChar *) content);
}

int ast_xml_doc_dump_file(FILE *output, struct ast_xml_doc *doc)
{
   return xmlDocDump(output, (xmlDocPtr)doc);
}

const char *ast_xml_node_get_name(struct ast_xml_node *node)
{
   return (const char *) ((xmlNode *) node)->name;
}

struct ast_xml_node *ast_xml_node_get_children(struct ast_xml_node *node)
{
   return (struct ast_xml_node *) ((xmlNode *) node)->children;
}

struct ast_xml_node *ast_xml_node_get_next(struct ast_xml_node *node)
{
   return (struct ast_xml_node *) ((xmlNode *) node)->next;
}

struct ast_xml_node *ast_xml_node_get_prev(struct ast_xml_node *node)
{
   return (struct ast_xml_node *) ((xmlNode *) node)->prev;
}

struct ast_xml_node *ast_xml_node_get_parent(struct ast_xml_node *node)
{
   return (struct ast_xml_node *) ((xmlNode *) node)->parent;
}

struct ast_xml_node *ast_xml_xpath_get_first_result(struct ast_xml_xpath_results *results)
{
   return (struct ast_xml_node *) ((xmlXPathObjectPtr) results)->nodesetval->nodeTab[0];
}

void ast_xml_xpath_results_free(struct ast_xml_xpath_results *results)
{
   xmlXPathFreeObject((xmlXPathObjectPtr) results);
}

int ast_xml_xpath_num_results(struct ast_xml_xpath_results *results)
{
   return ((xmlXPathObjectPtr) results)->nodesetval->nodeNr;
}

struct ast_xml_xpath_results *ast_xml_query(struct ast_xml_doc *doc, const char *xpath_str)
{
   xmlXPathContextPtr context;
   xmlXPathObjectPtr result;
   if (!(context = xmlXPathNewContext((xmlDoc *) doc))) {
      ast_log(LOG_ERROR, "Could not create XPath context!\n");
      return NULL;
   }
   result = xmlXPathEvalExpression((xmlChar *) xpath_str, context);
   xmlXPathFreeContext(context);
   if (!result) {
      ast_log(LOG_WARNING, "Error for query: %s\n", xpath_str);
      return NULL;
   }
   if (xmlXPathNodeSetIsEmpty(result->nodesetval)) {
      xmlXPathFreeObject(result);
      ast_debug(5, "No results for query: %s\n", xpath_str);
      return NULL;
   }
   return (struct ast_xml_xpath_results *) result;
}

#endif /* defined(HAVE_LIBXML2) */