guix/nix/libutil/xml-writer.cc

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2014-12-17 22:00:42 +00:00
#include <assert.h>
#include "xml-writer.hh"
namespace nix {
XMLWriter::XMLWriter(bool indent, std::ostream & output)
: output(output), indent(indent)
{
output << "<?xml version='1.0' encoding='utf-8'?>" << std::endl;
closed = false;
}
XMLWriter::~XMLWriter()
{
close();
}
void XMLWriter::close()
{
if (closed) return;
while (!pendingElems.empty()) closeElement();
closed = true;
}
void XMLWriter::indent_(unsigned int depth)
{
if (!indent) return;
output << string(depth * 2, ' ');
}
void XMLWriter::openElement(const string & name,
const XMLAttrs & attrs)
{
assert(!closed);
indent_(pendingElems.size());
output << "<" << name;
writeAttrs(attrs);
output << ">";
if (indent) output << std::endl;
pendingElems.push_back(name);
}
void XMLWriter::closeElement()
{
assert(!pendingElems.empty());
indent_(pendingElems.size() - 1);
output << "</" << pendingElems.back() << ">";
if (indent) output << std::endl;
pendingElems.pop_back();
if (pendingElems.empty()) closed = true;
}
void XMLWriter::writeEmptyElement(const string & name,
const XMLAttrs & attrs)
{
assert(!closed);
indent_(pendingElems.size());
output << "<" << name;
writeAttrs(attrs);
output << " />";
if (indent) output << std::endl;
}
void XMLWriter::writeAttrs(const XMLAttrs & attrs)
{
for (XMLAttrs::const_iterator i = attrs.begin(); i != attrs.end(); ++i) {
output << " " << i->first << "=\"";
for (unsigned int j = 0; j < i->second.size(); ++j) {
char c = i->second[j];
if (c == '"') output << "&quot;";
else if (c == '<') output << "&lt;";
else if (c == '>') output << "&gt;";
else if (c == '&') output << "&amp;";
/* Escape newlines to prevent attribute normalisation (see
XML spec, section 3.3.3. */
else if (c == '\n') output << "&#xA;";
else output << c;
}
output << "\"";
}
}
}