Example of svg parsing

[Alexander Aravenkov]

Hi! Do you have some full example for parsing SVG? So what i did: created SVG file in SVG-editor, read this file using std::ifstream, added svg-text to rapidxml and tried to parse. And rapidxml create exception with text "Error loading SCG: second colon in element name". Full code of my programm and SVG text below:

Programm:

#include "stdafx.h"

#include <rapidxml_ns/rapidxml_ns.hpp>

#include <svgpp/policy/xml/rapidxml_ns.hpp>

#include <svgpp/svgpp.hpp>

#include <iostream>

#include <fstream>

#include <string>

using namespace svgpp;

typedef rapidxml_ns::xml_node<> const * xml_element_t;

class Context

{

public:

void on_enter_element(tag::element::any)

{

}

void on_exit_element()

{

}

void path_move_to(double x, double y, tag::coordinate::absolute)

{

}

void path_line_to(double x, double y, tag::coordinate::absolute)

{

}

void path_cubic_bezier_to(

double x1, double y1,

double x2, double y2,

double x, double y,

tag::coordinate::absolute)

{

}

void path_quadratic_bezier_to(

double x1, double y1,

double x, double y,

tag::coordinate::absolute)

{

}

void path_elliptical_arc_to(

double rx, double ry, double x_axis_rotation,

bool large_arc_flag, bool sweep_flag,

double x, double y,

tag::coordinate::absolute)

{

}

void path_close_subpath()

{

}

void path_exit()

{

}

};

typedef

boost::mpl::set<

// SVG Structural Elements

tag::element::svg,

tag::element::g,

// SVG Shape Elements

tag::element::circle,

tag::element::ellipse,

tag::element::line,

tag::element::path,

tag::element::polygon,

tag::element::polyline,

tag::element::rect

>::type processed_elements_t;

void loadSvg(xml_element_t xml_root_element)

{

Context context;

document_traversal<

processed_elements<processed_elements_t>,

processed_attributes<traits::shapes_attributes_by_element>

>::load_document(xml_root_element, context);

}

int main()

{

std::string svg_text;

std::ifstream file;

file.open("d:\\Temp\\drawing.svg", std::ios_base::in);

if (file.is_open())

{

while (!file.eof())

{

std::string tmp;

file >> tmp;

svg_text += tmp;

}

}

rapidxml_ns::xml_document<> doc;    // character type defaults to char

try

{

doc.parse<0>((char*)svg_text.c_str());

if (rapidxml_ns::xml_node<> * svg_element = doc.first_node("svg"))

{

loadSvg(svg_element);

}

}

catch (std::exception const & e)

{

std::cerr << "Error loading SVG: " << e.what() << std::endl;

return 1;

}

return 0;

}

SVG file:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<svg

   xmlns:dc="http://purl.org/dc/elements/1.1/"

   xmlns:cc="http://creativecommons.org/ns#"

   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"

   xmlns:svg="http://www.w3.org/2000/svg"

   xmlns="http://www.w3.org/2000/svg"

   id="svg8"

   version="1.1"

   viewBox="0 0 210 297"

   height="297mm"

   width="210mm">

  <defs

     id="defs2" />

  <metadata

     id="metadata5">

    <rdf:RDF>

      <cc:Work

         rdf:about="">

        <dc:format>image/svg+xml</dc:format>

        <dc:type

           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />

        <dc:title></dc:title>

      </cc:Work>

    </rdf:RDF>

  </metadata>

  <g

     id="layer1">

    <rect

       y="46.023808"

       x="40.82143"

       height="128.5119"

       width="124.73214"

       id="rect18"

       style="fill:#00ff00;stroke-width:0.26458332" />

    <rect

       y="126.15475"

       x="96.005951"

       height="109.61309"

       width="76.351196"

       id="rect20"

       style="fill:#0000ff;stroke-width:0.26458332" />

  </g>

</svg>

[svgpp]

Hi Alexander,

Your code that reads from file concatenates lines dropping new line characters so you're getting invalid XML like <cc:Workrdf:about="">.

You may use RapidXML utils to read from file or any correct function to read file content into string.

Excerpts from svgpp/src/samples/sample_animation.cpp:

#include <rapidxml_ns/rapidxml_ns_utils.hpp>

rapidxml_ns::file<> xml_file(argv[1]);
	rapidxml_ns::xml_document<> doc;
	doc.parse<rapidxml_ns::parse_no_string_terminators>(xml_file.data());

Regards,

Oleg