static void apply(Symbolizer & sym, keys key, std::string const& name, xml_node const& node)
{
using value_type = T;
try
{
boost::optional<value_type> val = node.get_opt_attr<value_type>(name);
if (val) put(sym, key, *val);
}
catch (config_error const& ex)
{
// try parsing as an expression
boost::optional<expression_ptr> val = node.get_opt_attr<expression_ptr>(name);
if (val)
{
// first try pre-evaluate expressions which don't have dynamic properties
auto result = pre_evaluate_expression<mapnik::value>(*val);
if (std::get<1>(result))
{
set_property_from_value(sym, key,std::get<0>(result));
}
else
{
// expression_ptr
put(sym, key, *val);
}
}
else
{
throw;
}
}
}
static void apply(Symbolizer & sym, keys key, std::string const& name, xml_node const & node)
{
boost::optional<std::string> str = node.get_opt_attr<std::string>(name);
if (str)
{
std::vector<double> buf;
dash_array dash;
if (util::parse_dasharray(*str,buf) && util::add_dashes(buf,dash))
{
put(sym,key,dash);
}
else
{
boost::optional<expression_ptr> val = node.get_opt_attr<expression_ptr>(name);
if (val)
{
// first try pre-evaluate expressions which don't have dynamic properties
auto result = pre_evaluate_expression<mapnik::value>(*val);
if (std::get<1>(result))
{
set_property_from_value(sym, key,std::get<0>(result));
}
else
{
// expression_ptr
put(sym, key, *val);
}
}
else
{
throw config_error(std::string("Failed to parse dasharray ") +
"'. Expected a " +
"list of floats or 'none' but got '" + (*str) + "'");
}
}
}
}
