1 files changed, 94 insertions, 0 deletions
diff --git a/nix/libutil/xml-writer.cc b/nix/libutil/xml-writer.cc
new file mode 100644
index 0000000000..01794001b2
--- /dev/null
+++ b/nix/libutil/xml-writer.cc
@@ -0,0 +1,94 @@
+#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 << "\"";
+    }
+}
+
+
+}