mapnik/src/parse_path.cpp
2013-03-14 13:32:11 +08:00

150 lines
4.3 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
*
*****************************************************************************/
#include <mapnik/parse_path.hpp>
#include <mapnik/path_expression_grammar.hpp>
#include <mapnik/config.hpp>
#include <mapnik/attribute.hpp>
#include <mapnik/feature.hpp>
#include <mapnik/value.hpp>
// boost
#include <boost/variant.hpp>
#include <boost/foreach.hpp>
#include <boost/make_shared.hpp>
namespace mapnik {
path_expression_ptr parse_path(std::string const& str)
{
path_expression_grammar<std::string::const_iterator> g;
return parse_path(str,g);
}
path_expression_ptr parse_path(std::string const& str,
path_expression_grammar<std::string::const_iterator> const& g)
{
path_expression path;
std::string::const_iterator itr = str.begin();
std::string::const_iterator end = str.end();
bool r = qi::phrase_parse(itr, end, g, boost::spirit::standard_wide::space, path);
if (r && itr == end)
{
return boost::make_shared<path_expression>(path); //path;
}
else
{
throw std::runtime_error("Failed to parse path expression: \"" + str + "\"");
}
}
namespace path_processor_detail {
struct path_visitor_ : boost::static_visitor<void>
{
path_visitor_ (std::string & filename, feature_impl const& f)
: filename_(filename),
feature_(f) {}
void operator() (std::string const& token) const
{
filename_ += token;
}
void operator() (attribute const& attr) const
{
// convert mapnik::value to std::string
value const& val = feature_.get(attr.name());
filename_ += val.to_string();
}
std::string & filename_;
feature_impl const& feature_;
};
struct to_string_ : boost::static_visitor<void>
{
to_string_ (std::string & str)
: str_(str) {}
void operator() (std::string const& token) const
{
str_ += token;
}
void operator() (attribute const& attr) const
{
str_ += "[";
str_ += attr.name();
str_ += "]";
}
std::string & str_;
};
struct collect_ : boost::static_visitor<void>
{
collect_ (std::set<std::string> & cont)
: cont_(cont) {}
void operator() (std::string const& token) const
{
boost::ignore_unused_variable_warning(token);
}
void operator() (attribute const& attr) const
{
cont_.insert(attr.name());
}
std::set<std::string> & cont_;
};
}
std::string path_processor::evaluate(path_expression const& path,feature_impl const& f)
{
std::string out;
path_processor_detail::path_visitor_ eval(out,f);
BOOST_FOREACH( mapnik::path_component const& token, path)
boost::apply_visitor(eval,token);
return out;
}
std::string path_processor::to_string(path_expression const& path)
{
std::string str;
path_processor_detail::to_string_ visitor(str);
BOOST_FOREACH( mapnik::path_component const& token, path)
boost::apply_visitor(visitor,token);
return str;
}
void path_processor::collect_attributes(path_expression const& path, std::set<std::string>& names)
{
path_processor_detail::collect_ visitor(names);
BOOST_FOREACH( mapnik::path_component const& token, path)
boost::apply_visitor(visitor,token);
}
}