Method XMLEsc

libraries/lib-xml/XMLWriter.cpp:227–292

See http://www.w3.org/TR/REC-xml for reference

// See http://www.w3.org/TR/REC-xml for reference
wxString XMLWriter::XMLEsc(const wxString & s)
{
   wxString result;
   int len = s.length();

   for(int i=0; i<len; i++) {
      wxUChar c = s.GetChar(i);

      switch (c) {
         case wxT('\''):
            result += wxT("&apos;");
         break;

         case wxT('"'):
            result += wxT("&quot;");
         break;

         case wxT('&'):
            result += wxT("&amp;");
         break;

         case wxT('<'):
            result += wxT("&lt;");
         break;

         case wxT('>'):
            result += wxT("&gt;");
         break;

         default:
            if (sizeof(c) == 2 && c >= MIN_HIGH_SURROGATE && c <= MAX_HIGH_SURROGATE && i < len - 1) {
               // If wxUChar is 2 bytes, then supplementary characters (those greater than U+FFFF) are represented
               // with a high surrogate (U+D800..U+DBFF) followed by a low surrogate (U+DC00..U+DFFF).
               // Handle those here.
               wxUChar c2 = s.GetChar(++i);
               if (c2 >= MIN_LOW_SURROGATE && c2 <= MAX_LOW_SURROGATE) {
                  // Surrogate pair found; simply add it to the output string.
                  result += c;
                  result += c2;
               }
               else {
                  // That high surrogate isn't paired, so ignore it.
                  i--;
               }
            }
            else if (!wxIsprint(c)) {
               //ignore several characters such ase eot (0x04) and stx (0x02) because it makes expat parser bail
               //see xmltok.c in expat checkCharRefNumber() to see how expat bails on these chars.
               //also see wxWidgets-2.8.12/src/expat/lib/asciitab.h to see which characters are nonxml compatible
               //post decode (we can still encode '&' and '<' with this table, but it prevents us from encoding eot)
               //everything is compatible past ascii 0x20 except for surrogates and the noncharacters U+FFFE and U+FFFF,
               //so we don't check the compatibility table higher than this.
               if((c> 0x1F || charXMLCompatiblity[c]!=0) &&
                     (c < MIN_HIGH_SURROGATE || c > MAX_LOW_SURROGATE) &&
                     c != NONCHARACTER_FFFE && c != NONCHARACTER_FFFF)
                  result += wxString::Format(wxT("&#x%04x;"), c);
            }
            else {