mapnik/src/libxml2_loader.cpp

238 lines
7.1 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2011 Artem Pavlenko
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
#ifdef HAVE_LIBXML2
#include <mapnik/libxml2_loader.hpp>
#include <mapnik/config_error.hpp>
#include <boost/utility.hpp>
#include <boost/property_tree/ptree.hpp>
#include <boost/filesystem/operations.hpp>
#include <libxml/parser.h>
#include <libxml/tree.h>
#include <libxml/parserInternals.h>
#include <libxml/xinclude.h>
#include <iostream>
using boost::property_tree::ptree;
using namespace std;
//#define DEFAULT_OPTIONS (XML_PARSE_NOENT | XML_PARSE_NOBLANKS | XML_PARSE_DTDLOAD | XML_PARSE_NOCDATA)
#define DEFAULT_OPTIONS (XML_PARSE_NOERROR | XML_PARSE_NOENT | XML_PARSE_NOBLANKS | XML_PARSE_DTDLOAD | XML_PARSE_NOCDATA)
namespace mapnik
{
class libxml2_loader : boost::noncopyable
{
public:
libxml2_loader(const char *encoding = NULL, int options = DEFAULT_OPTIONS, const char *url = NULL) :
ctx_( 0 ),
encoding_( encoding ),
options_( options ),
url_( url )
{
LIBXML_TEST_VERSION;
ctx_ = xmlNewParserCtxt();
if ( ! ctx_ )
{
throw std::runtime_error("Failed to create parser context.");
}
}
~libxml2_loader()
{
if (ctx_)
{
xmlFreeParserCtxt(ctx_);
}
}
void load( const std::string & filename, ptree & pt )
{
boost::filesystem::path path(filename);
if ( !boost::filesystem::exists( path ) ) {
throw config_error(string("Could not load map file '") +
filename + "': File does not exist");
}
xmlDocPtr doc = xmlCtxtReadFile(ctx_, filename.c_str(), encoding_, options_);
if ( !doc )
{
xmlError * error = xmlCtxtGetLastError( ctx_ );
std::ostringstream os;
os << "XML document not well formed";
if (error)
{
os << ": " << std::endl << error->message;
// remove CR
std::string msg = os.str().substr(0, os.str().size() - 1);
config_error ex( msg );
os.str("");
os << "(encountered in file '" << error->file << "' at line "
<< error->line << ")";
ex.append_context( os.str() );
throw ex;
}
}
/*
if ( ! ctx->valid )
{
std::clog << "### ERROR: Failed to validate DTD."
<< std::endl;
}
*/
load(doc, pt);
}
void load( const int fd, ptree & pt )
{
xmlDocPtr doc = xmlCtxtReadFd(ctx_, fd, url_, encoding_, options_);
load(doc, pt);
}
void load_string( const std::string & buffer, ptree & pt, std::string const & base_path )
{
if (!base_path.empty())
{
boost::filesystem::path path(base_path);
if ( ! boost::filesystem::exists( path ) ) {
throw config_error(string("Could not locate base_path '") +
base_path + "': file or directory does not exist");
}
}
xmlDocPtr doc = xmlCtxtReadMemory(ctx_, buffer.data(), buffer.length(), base_path.c_str(), encoding_, options_);
load(doc, pt);
}
void load( const xmlDocPtr doc, ptree & pt )
{
if ( !doc )
{
xmlError * error = xmlCtxtGetLastError( ctx_ );
std::ostringstream os;
os << "XML document not well formed";
if (error)
{
os << ": " << std::endl << error->message;
}
throw config_error(os.str());
}
int iXIncludeReturn = xmlXIncludeProcessFlags( doc, options_ );
if (iXIncludeReturn < 0)
{
xmlFreeDoc(doc);
throw config_error("XML XInclude error. One or more files failed to load.");
}
xmlNode * root = xmlDocGetRootElement( doc );
if ( ! root ) {
xmlFreeDoc(doc);
throw config_error("XML document is empty.");
}
populate_tree( root, pt );
xmlFreeDoc(doc);
}
private:
void append_attributes( xmlAttr * attributes, ptree & pt)
{
if (attributes)
{
ptree::iterator it = pt.push_back( ptree::value_type( "<xmlattr>", ptree() ));
ptree & attr_list = it->second;
xmlAttr * cur_attr = attributes;
for (; cur_attr; cur_attr = cur_attr->next )
{
ptree::iterator it = attr_list.push_back(
ptree::value_type( (char*)cur_attr->name, ptree() ));
it->second.put_value( (char*) cur_attr->children->content );
}
}
}
void populate_tree( xmlNode * node, ptree & pt )
{
xmlNode * cur_node = node;
for (; cur_node; cur_node = cur_node->next )
{
switch (cur_node->type)
{
case XML_ELEMENT_NODE:
{
ptree::iterator it = pt.push_back( ptree::value_type(
(char*)cur_node->name, ptree() ));
append_attributes( cur_node->properties, it->second);
populate_tree( cur_node->children, it->second );
}
break;
case XML_TEXT_NODE:
pt.put_value( (char*) cur_node->content );
break;
case XML_COMMENT_NODE:
{
ptree::iterator it = pt.push_back(
ptree::value_type( "<xmlcomment>", ptree() ));
it->second.put_value( (char*) cur_node->content );
}
break;
default:
break;
}
}
}
xmlParserCtxtPtr ctx_;
const char *encoding_;
int options_;
const char *url_;
};
void read_xml2( std::string const & filename, boost::property_tree::ptree & pt)
{
libxml2_loader loader;
loader.load( filename, pt );
}
void read_xml2_string( std::string const & str, boost::property_tree::ptree & pt, std::string const & base_path)
{
libxml2_loader loader;
loader.load_string( str, pt, base_path );
}
} // end of namespace mapnik
#endif