mapnik/plugins/input/raster/raster_datasource.cpp
Artem Pavlenko 37f49e29cc Applied patches from Martijn van Oosterhout:
1. The first allows the user to add a <FileSource
name="foo">/home/bar/baz/</FileSource> to the beginning of the file
and then in any of the symbolisers you can say:

<FooSymboliser base="foo" name="bridge">
It it will refer to the file /home/bar/baz/bridge.

2. The second allows you to create Datasource templates at the top
level, which can be used later in the actual layers like so:
<Map>
  <Datasource name="db">
   <Paramaeter name="host">/tmp</Parameter>
  </Datasource>
  <Layer name="lay">
    <Datasource base="db">
      <Parameter name="table">points</Parameter>
    </Datasource>
  </Layer>
</Map>

And the host parameter will be used in the layer.

3. The third adds the "base" parameter to the raster and shape input
plugins. All it does is specify a path to prefix to the filename prior
to using it. Together with the above feature it allows things like:
<Map>
  <Datasource name="shapes">
   <Paramaeter name="base">/home/foo/shapes</Parameter>
  </Datasource>
  <Layer name="lay">
    <Datasource base="shapes">
      <Parameter name="file">places</Parameter>
    </Datasource>
  </Layer>
</Map>

And it will use the shapefile /home/foo/shapes/places
2007-12-17 14:21:04 +00:00

108 lines
3.2 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2006 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
*
*****************************************************************************/
//$Id: raster_datasource.cc 44 2005-04-22 18:53:54Z pavlenko $
// boost
#include <boost/lexical_cast.hpp>
// mapnik
#include <mapnik/image_reader.hpp>
#include "raster_featureset.hpp"
#include "raster_info.hpp"
#include "raster_datasource.hpp"
using mapnik::datasource;
using mapnik::parameters;
DATASOURCE_PLUGIN(raster_datasource)
using std::clog;
using std::endl;
using boost::lexical_cast;
using boost::bad_lexical_cast;
using mapnik::layer_descriptor;
using mapnik::featureset_ptr;
using mapnik::query;
using mapnik::coord2d;
using mapnik::datasource_exception;
raster_datasource::raster_datasource(const parameters& params)
: datasource (params),
desc_(*params.get<std::string>("type"),"utf-8")
{
boost::optional<std::string> file=params.get<std::string>("file");
boost::optional<std::string> base=params.get<std::string>("base");
if (!file) throw datasource_exception("missing <file> parameter ");
if (base)
filename_ = *base + "/" + *file;
else
filename_ = *file;
format_=*params.get<std::string>("format","tiff");
boost::optional<double> lox = params.get<double>("lox");
boost::optional<double> loy = params.get<double>("loy");
boost::optional<double> hix = params.get<double>("hix");
boost::optional<double> hiy = params.get<double>("hiy");
if (lox && loy && hix && hiy)
{
extent_.init(*lox,*loy,*hix,*hiy);
}
else throw datasource_exception("<lox> <loy> <hix> <hiy> are required");
}
raster_datasource::~raster_datasource() {}
int raster_datasource::type() const
{
return datasource::Raster;
}
std::string raster_datasource::name_="raster";
std::string raster_datasource::name()
{
return name_;
}
mapnik::Envelope<double> raster_datasource::envelope() const
{
return extent_;
}
layer_descriptor raster_datasource::get_descriptor() const
{
return desc_;
}
featureset_ptr raster_datasource::features(query const& q) const
{
raster_info info(filename_,format_,extent_);
single_file_policy policy(info); //todo: handle different policies!
return featureset_ptr(new raster_featureset<single_file_policy>(policy,q));
}
featureset_ptr raster_datasource::features_at_point(coord2d const&) const
{
return featureset_ptr();
}