mapnik/tests/cpp_tests/svg_renderer_tests/root_element_test.cpp

#define BOOST_TEST_MODULE root_element_test

/*
 * This test module contains several generators for 
 * the SVG root element.
 */

// boost.test
#include <boost/test/included/unit_test.hpp>

// boost.spirit
#include <boost/spirit/include/karma.hpp>
#include <boost/spirit/repository/include/karma_confix.hpp>

// boost
#include <boost/fusion/tuple.hpp>

// stl
#include <string>
#include <sstream>

namespace karma = boost::spirit::karma;
namespace repository = boost::spirit::repository;
namespace fusion = boost::fusion;
using namespace karma;

struct F 
{
    F() :
	width(100),
	height(100),
	version(1.1),
	xmlns("http://www.w3.org/2000/svg"),
	expected_output("<svg width=\"100px\" height=\"100px\" version=\"1.1\" xmlns=\"http://www.w3.org/2000/svg\">") {}

    ~F() {}

    const int width;
    const int height;
    const float version;
    const std::string xmlns;
    const std::string expected_output;
    std::ostringstream actual_output;
};

/*
 * This test case uses one compound generator to generate the SVG  element.
 *
 * It makes only one call to the format function and uses an ostringstream
 * as its output destination.
 *
 * The attribute values are provided as arguments to the format function.
 * The disadvantage of this is that the number of arguments is limited
 * by the preprocessor constant SPIRIT_ARGUMENTS_LIMIT, whose default
 * value is 10. The advantage is that they can be of any type (as long
 * as they are compatible with the corresponding generator type).
 */
BOOST_FIXTURE_TEST_CASE(bgcolor_stream_test_case, F)
{
    actual_output
	<< format(
	    "<svg width=\"" << int_ << string << "\" "
	    << "height=\"" << int_ << string << "\" "
	    << "version=\"" << float_ << "\" "
	    << "xmlns=\"" << string << "\""
	    << ">",
	    width, "px", height, "px", version, xmlns);

    BOOST_CHECK_EQUAL(actual_output.str(), expected_output);
}

/*
 * This test case uses confix to wrap each xml attribute's value
 * inside double quotes.
 *
 * Notice that the generators' attribute list contains also tuples.
 * Tuples are needed to specify each confix's attributes that contain
 * more than one generator, like confix()[int_ << string] (this 
 * generator needs a tuple: tuple<int, string>).
 *
 * The difference between this generator and the one in test case
 * 'bgcolor_stream_test_case' is the use of less << operators and
 * a more clean handling of double quotes.
 */
BOOST_FIXTURE_TEST_CASE(bgcolor_stream_confix_test_case, F)
{
    using repository::confix;
    using fusion::tuple;

    actual_output
	<< format(
	    "<svg width=" << confix('"', '"')[int_ << string]
	    << " height=" << confix('"', '"')[int_ << string]
	    << " version=" << confix('"', '"')[float_]
	    << " xmlns=" << confix('"', '"')[string]
	    << ">",
	    tuple<int, std::string>(width, "px"), tuple<int, std::string>(height, "px"), version, xmlns); 
    
    BOOST_CHECK_EQUAL(actual_output.str(), expected_output);
}

/*
 * This test case generates the angle brackets of the svg/xml tag
 * using confix. notice that a confix generator can be part of another
 * confix generator's expression.
 *
 * Notice also that the attribute list is the same as in 
 * 'bgcolor_stream_confix_test_case'. From this one can see that each 
 * generator is meant to have a list of attributes if it has more than one. 
 *
 * If the generator is nested inside another generator, the former's attribute 
 * list will be another list (a tuple, for example) inside the latter's.
 */
BOOST_FIXTURE_TEST_CASE(bgcolor_stream_confix_complete_test_case, F)
{
    using repository::confix;
    using fusion::tuple;

    actual_output
	<< format(
	    confix('<', ">")[
		"svg width=" << confix('"', '"')[int_ << string]
		<< " height=" << confix('"', '"')[int_ << string]
		<< " version=" << confix('"', '"')[float_]
		<< " xmlns=" << confix('"', '"')[string]],
	    tuple<int, std::string>(width, "px"), tuple<int, std::string>(height, "px"), version, xmlns); 
    
    BOOST_CHECK_EQUAL(actual_output.str(), expected_output);
}

/*
 * This test case uses an iterator to receive the generated
 * output. The iterator comes from the std::ostringstream that's
 * been used in the previous test cases, so the output is
 * actually generated into the stream.
 *
 * Using iterators instead of streams has the advantage that
 * more advanced concepts are implemented in karma for them,
 * like rules and grammars.
 */
BOOST_FIXTURE_TEST_CASE(bgcolor_stream_iterator_test_case, F)
{
    using repository::confix;
    using fusion::tuple;

    std::ostream_iterator<char> actual_output_iterator(actual_output);

    generate(
	actual_output_iterator,
	confix("<", ">")[
	    "svg width=" << confix('"', '"')[int_ << string]
	    << " height=" << confix('"', '"')[int_ << string]
	    << " version=" << confix('"', '"')[float_]
	    << " xmlns=" << confix('"', '"')[string]],
	tuple<int, std::string>(width, "px"), tuple<int, std::string>(height, "px"), version, xmlns);

    BOOST_CHECK_EQUAL(actual_output.str(), expected_output);
}