lyx_mirror/src/output_xhtml.cpp
Richard Heck a81bf77314 Change the escaping mechanism for XHTML output and so allow a fix for
bug #7061.


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@36455 a592a061-630c-0410-9148-cb99ea01b6c8
2010-11-24 15:27:36 +00:00

935 lines
24 KiB
C++

/**
* \file output_xhtml.cpp
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Richard Heck
*
* This code is based upon output_docbook.cpp
*
* Full author contact details are available in file CREDITS.
*/
#include <config.h>
#include "output_xhtml.h"
#include "Buffer.h"
#include "buffer_funcs.h"
#include "BufferParams.h"
#include "Counters.h"
#include "Font.h"
#include "Layout.h"
#include "OutputParams.h"
#include "Paragraph.h"
#include "ParagraphList.h"
#include "ParagraphParameters.h"
#include "sgml.h"
#include "Text.h"
#include "TextClass.h"
#include "support/convert.h"
#include "support/debug.h"
#include "support/lassert.h"
#include "support/lstrings.h"
#include "support/textutils.h"
#include <vector>
using namespace std;
using namespace lyx::support;
namespace lyx {
namespace html {
docstring escapeChar(char_type c, XHTMLStream::EscapeSettings e)
{
docstring str;
switch (e) {
case XHTMLStream::ESCAPE_NONE:
str += c;
break;
case XHTMLStream::ESCAPE_ALL:
if (c == '<') {
str += "&lt;";
break;
} else if (c == '>') {
str += "&gt;";
break;
}
// fall through
case XHTMLStream::ESCAPE_AND:
if (c == '&')
str += "&amp;";
else
str +=c ;
break;
}
return str;
}
// escape what needs escaping
docstring htmlize(docstring const & str, XHTMLStream::EscapeSettings e) {
odocstringstream d;
docstring::const_iterator it = str.begin();
docstring::const_iterator en = str.end();
for (; it != en; ++it)
d << escapeChar(*it, e);
return d.str();
}
string escapeChar(char c, XHTMLStream::EscapeSettings e)
{
string str;
switch (e) {
case XHTMLStream::ESCAPE_NONE:
str += c;
break;
case XHTMLStream::ESCAPE_ALL:
if (c == '<') {
str += "&lt;";
break;
} else if (c == '>') {
str += "&gt;";
break;
}
// fall through
case XHTMLStream::ESCAPE_AND:
if (c == '&')
str += "&amp;";
else
str +=c ;
break;
}
return str;
}
// escape what needs escaping
string htmlize(string const & str, XHTMLStream::EscapeSettings e) {
ostringstream d;
string::const_iterator it = str.begin();
string::const_iterator en = str.end();
for (; it != en; ++it)
d << escapeChar(*it, e);
return d.str();
}
string cleanAttr(string const & str)
{
string newname;
string::const_iterator it = str.begin();
string::const_iterator en = str.end();
for (; it != en; ++it)
newname += isalnum(*it) ? *it : '_';
return newname;
}
docstring cleanAttr(docstring const & str)
{
docstring newname;
docstring::const_iterator it = str.begin();
docstring::const_iterator en = str.end();
for (; it != en; ++it) {
char_type const c = *it;
newname += isAlnumASCII(c) ? c : char_type('_');
}
return newname;
}
bool isFontTag(string const & s)
{
return s == "em" || s == "strong"; // others?
}
docstring StartTag::asTag() const
{
string output = "<" + tag_;
if (!attr_.empty())
output += " " + html::htmlize(attr_, XHTMLStream::ESCAPE_NONE);
output += ">";
return from_utf8(output);
}
docstring StartTag::asEndTag() const
{
string output = "</" + tag_ + ">";
return from_utf8(output);
}
docstring EndTag::asEndTag() const
{
string output = "</" + tag_ + ">";
return from_utf8(output);
}
docstring CompTag::asTag() const
{
string output = "<" + tag_;
if (!attr_.empty())
output += " " + html::htmlize(attr_, XHTMLStream::ESCAPE_NONE);
output += " />";
return from_utf8(output);
}
} // namespace html
////////////////////////////////////////////////////////////////
///
/// XHTMLStream
///
////////////////////////////////////////////////////////////////
XHTMLStream::XHTMLStream(odocstream & os)
: os_(os), escape_(ESCAPE_ALL)
{}
void XHTMLStream::cr()
{
// tabs?
os_ << from_ascii("\n");
}
void XHTMLStream::writeError(std::string const & s)
{
LYXERR0(s);
os_ << from_utf8("<!-- Output Error: " + s + " -->");
}
bool XHTMLStream::closeFontTags()
{
if (tag_stack_.empty())
return true;
// first, we close any open font tags we can close
html::StartTag curtag = tag_stack_.back();
while (html::isFontTag(curtag.tag_)) {
os_ << curtag.asEndTag();
tag_stack_.pop_back();
if (tag_stack_.empty())
// this probably shouldn't happen, since then the
// font tags weren't in any other tag. but that
// problem will likely be caught elsewhere.
return true;
curtag = tag_stack_.back();
}
// so we've hit a non-font tag. let's see if any of the
// remaining tags are font tags.
TagStack::const_iterator it = tag_stack_.begin();
TagStack::const_iterator en = tag_stack_.end();
bool noFontTags = true;
for (; it != en; ++it) {
if (html::isFontTag(it->tag_)) {
writeError("Font tag `" + it->tag_ + "' still open in closeFontTags().\n"
"This is likely not a problem, but you might want to check.");
noFontTags = false;
}
}
return noFontTags;
}
void XHTMLStream::clearTagDeque()
{
while (!pending_tags_.empty()) {
html::StartTag const & tag = pending_tags_.front();
// tabs?
os_ << tag.asTag();
tag_stack_.push_back(tag);
pending_tags_.pop_front();
}
}
XHTMLStream & XHTMLStream::operator<<(docstring const & d)
{
clearTagDeque();
os_ << html::htmlize(d, escape_);
escape_ = ESCAPE_ALL;
return *this;
}
XHTMLStream & XHTMLStream::operator<<(const char * s)
{
clearTagDeque();
docstring const d = from_ascii(s);
os_ << html::htmlize(d, escape_);
escape_ = ESCAPE_ALL;
return *this;
}
XHTMLStream & XHTMLStream::operator<<(char_type c)
{
clearTagDeque();
os_ << html::escapeChar(c, escape_);
escape_ = ESCAPE_ALL;
return *this;
}
XHTMLStream & XHTMLStream::operator<<(char c)
{
clearTagDeque();
string const d = html::escapeChar(c, escape_);
escape_ = ESCAPE_ALL;
return *this;
}
XHTMLStream & XHTMLStream::operator<<(int i)
{
clearTagDeque();
os_ << i;
escape_ = ESCAPE_ALL;
return *this;
}
XHTMLStream & XHTMLStream::operator<<(EscapeSettings e)
{
escape_ = e;
return *this;
}
XHTMLStream & XHTMLStream::operator<<(html::StartTag const & tag)
{
if (tag.tag_.empty())
return *this;
pending_tags_.push_back(tag);
if (tag.keepempty_)
clearTagDeque();
return *this;
}
XHTMLStream & XHTMLStream::operator<<(html::CompTag const & tag)
{
if (tag.tag_.empty())
return *this;
clearTagDeque();
// tabs?
os_ << tag.asTag();
cr();
return *this;
}
bool XHTMLStream::isTagOpen(string const & stag)
{
TagStack::const_iterator sit = tag_stack_.begin();
TagStack::const_iterator const sen = tag_stack_.end();
for (; sit != sen; ++sit)
if (sit->tag_ == stag)
return true;
return false;
}
// this is complicated, because we want to make sure that
// everything is properly nested. the code ought to make
// sure of that, but we won't assert (yet) if we run into
// a problem. we'll just output error messages and try our
// best to make things work.
XHTMLStream & XHTMLStream::operator<<(html::EndTag const & etag)
{
if (etag.tag_.empty())
return *this;
// make sure there are tags to be closed
if (tag_stack_.empty()) {
writeError("Tried to close `" + etag.tag_
+ "' when no tags were open!");
return *this;
}
// first make sure we're not closing an empty tag
if (!pending_tags_.empty()) {
html::StartTag const & stag = pending_tags_.back();
if (etag.tag_ == stag.tag_) {
// we have <tag></tag>, so we discard it and remove it
// from the pending_tags_.
pending_tags_.pop_back();
return *this;
}
// there is a pending tag that isn't the one we are trying
// to close.
// is this tag itself pending?
// non-const iterators because we may call erase().
TagDeque::iterator dit = pending_tags_.begin();
TagDeque::iterator const den = pending_tags_.end();
for (; dit != den; ++dit) {
if (dit->tag_ == etag.tag_) {
// it was pending, so we just erase it
writeError("Tried to close pending tag `" + etag.tag_
+ "' when other tags were pending. Last pending tag is `"
+ pending_tags_.back().tag_ + "'. Tag discarded.");
pending_tags_.erase(dit);
return *this;
}
}
// so etag isn't itself pending. is it even open?
if (!isTagOpen(etag.tag_)) {
writeError("Tried to close `" + etag.tag_
+ "' when tag was not open. Tag discarded.");
return *this;
}
// ok, so etag is open.
// our strategy will be as below: we will do what we need to
// do to close this tag.
string estr = "Closing tag `" + etag.tag_
+ "' when other tags are pending. Discarded pending tags:\n";
for (dit = pending_tags_.begin(); dit != den; ++dit)
estr += dit->tag_ + "\n";
writeError(estr);
// clear the pending tags...
pending_tags_.clear();
// ...and then just fall through.
}
// is the tag we are closing the last one we opened?
if (etag.tag_ == tag_stack_.back().tag_) {
// output it...
os_ << etag.asEndTag();
// ...and forget about it
tag_stack_.pop_back();
return *this;
}
// we are trying to close a tag other than the one last opened.
// let's first see if this particular tag is still open somehow.
if (!isTagOpen(etag.tag_)) {
writeError("Tried to close `" + etag.tag_
+ "' when tag was not open. Tag discarded.");
return *this;
}
// so the tag was opened, but other tags have been opened since
// and not yet closed.
// if it's a font tag, though...
if (html::isFontTag(etag.tag_)) {
// it won't be a problem if the other tags open since this one
// are also font tags.
TagStack::const_reverse_iterator rit = tag_stack_.rbegin();
TagStack::const_reverse_iterator ren = tag_stack_.rend();
for (; rit != ren; ++rit) {
if (rit->tag_ == etag.tag_)
break;
if (!html::isFontTag(rit->tag_)) {
// we'll just leave it and, presumably, have to close it later.
writeError("Unable to close font tag `" + etag.tag_
+ "' due to open non-font tag `" + rit->tag_ + "'.");
return *this;
}
}
// so we have e.g.:
// <em>this is <strong>bold
// and are being asked to closed em. we want:
// <em>this is <strong>bold</strong></em><strong>
// first, we close the intervening tags...
html::StartTag curtag = tag_stack_.back();
// ...remembering them in a stack.
TagStack fontstack;
while (curtag.tag_ != etag.tag_) {
os_ << curtag.asEndTag();
fontstack.push_back(curtag);
tag_stack_.pop_back();
curtag = tag_stack_.back();
}
// now close our tag...
os_ << etag.asEndTag();
tag_stack_.pop_back();
// ...and restore the other tags.
rit = fontstack.rbegin();
ren = fontstack.rend();
for (; rit != ren; ++rit)
pending_tags_.push_back(*rit);
return *this;
}
// it wasn't a font tag.
// so other tags were opened before this one and not properly closed.
// so we'll close them, too. that may cause other issues later, but it
// at least guarantees proper nesting.
writeError("Closing tag `" + etag.tag_
+ "' when other tags are open, namely:");
html::StartTag curtag = tag_stack_.back();
while (curtag.tag_ != etag.tag_) {
writeError(curtag.tag_);
os_ << curtag.asEndTag();
tag_stack_.pop_back();
curtag = tag_stack_.back();
}
// curtag is now the one we actually want.
os_ << curtag.asEndTag();
tag_stack_.pop_back();
return *this;
}
// End code for XHTMLStream
namespace {
// convenience functions
inline void openTag(XHTMLStream & xs, Layout const & lay)
{
xs << html::StartTag(lay.htmltag(), lay.htmlattr());
}
void openTag(XHTMLStream & xs, Layout const & lay,
ParagraphParameters const & params)
{
// FIXME Are there other things we should handle here?
string const align = alignmentToCSS(params.align());
if (align.empty()) {
openTag(xs, lay);
return;
}
string attrs = lay.htmlattr() + " style='text-align: " + align + ";'";
xs << html::StartTag(lay.htmltag(), attrs);
}
inline void closeTag(XHTMLStream & xs, Layout const & lay)
{
xs << html::EndTag(lay.htmltag());
}
inline void openLabelTag(XHTMLStream & xs, Layout const & lay)
{
xs << html::StartTag(lay.htmllabeltag(), lay.htmllabelattr());
}
inline void closeLabelTag(XHTMLStream & xs, Layout const & lay)
{
xs << html::EndTag(lay.htmllabeltag());
}
inline void openItemTag(XHTMLStream & xs, Layout const & lay)
{
xs << html::StartTag(lay.htmlitemtag(), lay.htmlitemattr(), true);
}
void openItemTag(XHTMLStream & xs, Layout const & lay,
ParagraphParameters const & params)
{
// FIXME Are there other things we should handle here?
string const align = alignmentToCSS(params.align());
if (align.empty()) {
openItemTag(xs, lay);
return;
}
string attrs = lay.htmlattr() + " style='text-align: " + align + ";'";
xs << html::StartTag(lay.htmlitemtag(), attrs);
}
inline void closeItemTag(XHTMLStream & xs, Layout const & lay)
{
xs << html::EndTag(lay.htmlitemtag());
}
// end of convenience functions
ParagraphList::const_iterator searchParagraphHtml(
ParagraphList::const_iterator p,
ParagraphList::const_iterator const & pend)
{
for (++p; p != pend && p->layout().latextype == LATEX_PARAGRAPH; ++p)
;
return p;
}
ParagraphList::const_iterator searchEnvironmentHtml(
ParagraphList::const_iterator const pstart,
ParagraphList::const_iterator const & pend)
{
ParagraphList::const_iterator p = pstart;
Layout const & bstyle = p->layout();
size_t const depth = p->params().depth();
for (++p; p != pend; ++p) {
Layout const & style = p->layout();
// It shouldn't happen that e.g. a section command occurs inside
// a quotation environment, at a higher depth, but as of 6/2009,
// it can happen. We pretend that it's just at lowest depth.
if (style.latextype == LATEX_COMMAND)
return p;
// If depth is down, we're done
if (p->params().depth() < depth)
return p;
// If depth is up, we're not done
if (p->params().depth() > depth)
continue;
// Now we know we are at the same depth
if (style.latextype == LATEX_PARAGRAPH
|| style.latexname() != bstyle.latexname())
return p;
}
return pend;
}
ParagraphList::const_iterator makeParagraphs(Buffer const & buf,
XHTMLStream & xs,
OutputParams const & runparams,
Text const & text,
ParagraphList::const_iterator const & pbegin,
ParagraphList::const_iterator const & pend)
{
ParagraphList::const_iterator const begin = text.paragraphs().begin();
ParagraphList::const_iterator par = pbegin;
for (; par != pend; ++par) {
Layout const & lay = par->layout();
if (!lay.counter.empty())
buf.params().documentClass().counters().step(lay.counter, OutputUpdate);
// FIXME We should see if there's a label to be output and
// do something with it.
if (par != pbegin)
xs.cr();
// If we are already in a paragraph, and this is the first one, then we
// do not want to open the paragraph tag.
// we also do not want to open it if the current layout does not permit
// multiple paragraphs.
bool const opened = runparams.html_make_pars &&
(par != pbegin || !runparams.html_in_par);
if (opened)
openTag(xs, lay, par->params());
docstring const deferred =
par->simpleLyXHTMLOnePar(buf, xs, runparams, text.outerFont(distance(begin, par)));
// We want to issue the closing tag if either:
// (i) We opened it, and either html_in_par is false,
// or we're not in the last paragraph, anyway.
// (ii) We didn't open it and html_in_par is true,
// but we are in the first par, and there is a next par.
ParagraphList::const_iterator nextpar = par;
nextpar++;
bool const needclose =
(opened && (!runparams.html_in_par || nextpar != pend))
|| (!opened && runparams.html_in_par && par == pbegin && nextpar != pend);
if (needclose) {
closeTag(xs, lay);
xs.cr();
}
if (!deferred.empty()) {
xs << XHTMLStream::ESCAPE_NONE << deferred;
xs.cr();
}
}
return pend;
}
ParagraphList::const_iterator makeBibliography(Buffer const & buf,
XHTMLStream & xs,
OutputParams const & runparams,
Text const & text,
ParagraphList::const_iterator const & pbegin,
ParagraphList::const_iterator const & pend)
{
// FIXME XHTML
// Use TextClass::htmlTOCLayout() to figure out how we should look.
xs << html::StartTag("h2", "class='bibliography'");
xs << pbegin->layout().labelstring(false);
xs << html::EndTag("h2");
xs.cr();
xs << html::StartTag("div", "class='bibliography'");
xs.cr();
makeParagraphs(buf, xs, runparams, text, pbegin, pend);
xs << html::EndTag("div");
return pend;
}
bool isNormalEnv(Layout const & lay)
{
return lay.latextype == LATEX_ENVIRONMENT
|| lay.latextype == LATEX_BIB_ENVIRONMENT;
}
ParagraphList::const_iterator makeEnvironmentHtml(Buffer const & buf,
XHTMLStream & xs,
OutputParams const & runparams,
Text const & text,
ParagraphList::const_iterator const & pbegin,
ParagraphList::const_iterator const & pend)
{
ParagraphList::const_iterator const begin = text.paragraphs().begin();
ParagraphList::const_iterator par = pbegin;
Layout const & bstyle = par->layout();
depth_type const origdepth = pbegin->params().depth();
// open tag for this environment
openTag(xs, bstyle);
xs.cr();
// we will on occasion need to remember a layout from before.
Layout const * lastlay = 0;
while (par != pend) {
Layout const & style = par->layout();
// the counter only gets stepped if we're in some kind of list,
// or if it's the first time through.
// note that enum, etc, are handled automatically.
// FIXME There may be a bug here about user defined enumeration
// types. If so, then we'll need to take the counter and add "i",
// "ii", etc, as with enum.
Counters & cnts = buf.params().documentClass().counters();
docstring const & cntr = style.counter;
if (!style.counter.empty()
&& (par == pbegin || !isNormalEnv(style))
&& cnts.hasCounter(cntr)
)
cnts.step(cntr, OutputUpdate);
ParagraphList::const_iterator send;
// this will be positive, if we want to skip the initial word
// (if it's been taken for the label).
pos_type sep = 0;
switch (style.latextype) {
case LATEX_ENVIRONMENT:
case LATEX_LIST_ENVIRONMENT:
case LATEX_ITEM_ENVIRONMENT: {
// There are two possiblities in this case.
// One is that we are still in the environment in which we
// started---which we will be if the depth is the same.
if (par->params().depth() == origdepth) {
LASSERT(bstyle == style, /* */);
if (lastlay != 0) {
closeItemTag(xs, *lastlay);
lastlay = 0;
}
bool const labelfirst = style.htmllabelfirst();
if (!labelfirst)
openItemTag(xs, style, par->params());
// label output
if (style.labeltype != LABEL_NO_LABEL &&
style.htmllabeltag() != "NONE") {
if (isNormalEnv(style)) {
// in this case, we print the label only for the first
// paragraph (as in a theorem).
if (par == pbegin) {
docstring const lbl =
pbegin->params().labelString();
if (!lbl.empty()) {
openLabelTag(xs, style);
xs << lbl;
closeLabelTag(xs, style);
}
xs.cr();
}
} else { // some kind of list
if (style.labeltype == LABEL_MANUAL) {
openLabelTag(xs, style);
sep = par->firstWordLyXHTML(xs, runparams);
closeLabelTag(xs, style);
xs.cr();
}
else {
openLabelTag(xs, style);
xs << par->params().labelString();
closeLabelTag(xs, style);
xs.cr();
}
}
} // end label output
if (labelfirst)
openItemTag(xs, style, par->params());
par->simpleLyXHTMLOnePar(buf, xs, runparams,
text.outerFont(distance(begin, par)), sep);
++par;
// We may not want to close the tag yet, in particular:
// If we're not at the end...
if (par != pend
// and are doing items...
&& !isNormalEnv(style)
// and if the depth has changed...
&& par->params().depth() != origdepth) {
// then we'll save this layout for later, and close it when
// we get another item.
lastlay = &style;
} else
closeItemTag(xs, style);
xs.cr();
}
// The other possibility is that the depth has increased, in which
// case we need to recurse.
else {
send = searchEnvironmentHtml(par, pend);
par = makeEnvironmentHtml(buf, xs, runparams, text, par, send);
}
break;
}
case LATEX_PARAGRAPH:
send = searchParagraphHtml(par, pend);
par = makeParagraphs(buf, xs, runparams, text, par, send);
break;
// Shouldn't happen
case LATEX_BIB_ENVIRONMENT:
send = par;
++send;
par = makeParagraphs(buf, xs, runparams, text, par, send);
break;
// Shouldn't happen
case LATEX_COMMAND:
++par;
break;
}
}
if (lastlay != 0)
closeItemTag(xs, *lastlay);
closeTag(xs, bstyle);
xs.cr();
return pend;
}
void makeCommand(Buffer const & buf,
XHTMLStream & xs,
OutputParams const & runparams,
Text const & text,
ParagraphList::const_iterator const & pbegin)
{
Layout const & style = pbegin->layout();
if (!style.counter.empty())
buf.params().documentClass().counters().step(style.counter, OutputUpdate);
openTag(xs, style, pbegin->params());
// Label around sectioning number:
// FIXME Probably need to account for LABEL_MANUAL
if (style.labeltype != LABEL_NO_LABEL) {
openLabelTag(xs, style);
xs << pbegin->params().labelString();
closeLabelTag(xs, style);
// Otherwise the label might run together with the text
xs << from_ascii(" ");
}
ParagraphList::const_iterator const begin = text.paragraphs().begin();
pbegin->simpleLyXHTMLOnePar(buf, xs, runparams,
text.outerFont(distance(begin, pbegin)));
closeTag(xs, style);
xs.cr();
}
} // end anonymous namespace
void xhtmlParagraphs(Text const & text,
Buffer const & buf,
XHTMLStream & xs,
OutputParams const & runparams)
{
ParagraphList const & paragraphs = text.paragraphs();
ParagraphList::const_iterator par = paragraphs.begin();
ParagraphList::const_iterator pend = paragraphs.end();
OutputParams ourparams = runparams;
while (par != pend) {
if (par->params().startOfAppendix()) {
// FIXME: only the counter corresponding to toplevel
// sectioning should be reset
Counters & cnts = buf.masterBuffer()->params().documentClass().counters();
cnts.reset();
cnts.appendix(true);
}
Layout const & style = par->layout();
ParagraphList::const_iterator lastpar = par;
ParagraphList::const_iterator send;
switch (style.latextype) {
case LATEX_COMMAND: {
// The files with which we are working never have more than
// one paragraph in a command structure.
// FIXME
// if (ourparams.html_in_par)
// fix it so we don't get sections inside standard, e.g.
// note that we may then need to make runparams not const, so we
// can communicate that back.
// FIXME Maybe this fix should be in the routines themselves, in case
// they are called from elsewhere.
makeCommand(buf, xs, ourparams, text, par);
++par;
break;
}
case LATEX_ENVIRONMENT:
case LATEX_LIST_ENVIRONMENT:
case LATEX_ITEM_ENVIRONMENT: {
// FIXME Same fix here.
send = searchEnvironmentHtml(par, pend);
par = makeEnvironmentHtml(buf, xs, ourparams, text, par, send);
break;
}
case LATEX_BIB_ENVIRONMENT: {
// FIXME Same fix here.
send = searchEnvironmentHtml(par, pend);
par = makeBibliography(buf, xs, ourparams, text, par, send);
break;
}
case LATEX_PARAGRAPH:
send = searchParagraphHtml(par, pend);
par = makeParagraphs(buf, xs, ourparams, text, par, send);
break;
}
// FIXME??
// makeEnvironment may process more than one paragraphs and bypass pend
if (distance(lastpar, par) >= distance(lastpar, pend))
break;
}
}
string alignmentToCSS(LyXAlignment align) {
switch (align) {
case LYX_ALIGN_BLOCK:
// we are NOT going to use text-align: justify!!
case LYX_ALIGN_LEFT:
return "left";
case LYX_ALIGN_RIGHT:
return "right";
case LYX_ALIGN_CENTER:
return "center";
default:
break;
}
return "";
}
} // namespace lyx