/* htmlparse.cc: simple HTML parser for omega indexer
*
* ----START-LICENCE----
* Copyright 1999,2000,2001 BrightStation PLC
* Copyright 2001 Ananova Ltd
* Copyright 2002 Olly Betts
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
* -----END-LICENCE-----
*/
#ifndef lint
static char rcsid[] = "@(#$Id: htmlparse.cpp,v 1.3 2005-11-24 07:16:15 dockes Exp $ ";
#endif
//#include <config.h>
#include <algorithm>
#ifndef NO_NAMESPACES
using namespace std;
//using std::find;
//using std::find_if;
#endif /* NO_NAMESPACES */
#include "htmlparse.h"
#include <stdio.h>
#include <ctype.h>
#include "transcode.h"
map<string, string> HtmlParser::named_ents;
inline static bool
p_alpha(char c)
{
return isalpha(c);
}
inline static bool
p_notdigit(char c)
{
return !isdigit(c);
}
inline static bool
p_notxdigit(char c)
{
return !isxdigit(c);
}
inline static bool
p_notalnum(char c)
{
return !isalnum(c);
}
inline static bool
p_notwhitespace(char c)
{
return !isspace(c);
}
inline static bool
p_nottag(char c)
{
return !isalnum(c) && c != '.' && c != '-';
}
inline static bool
p_whitespacegt(char c)
{
return isspace(c) || c == '>';
}
inline static bool
p_whitespaceeqgt(char c)
{
return isspace(c) || c == '=' || c == '>';
}
/*
* The following array was taken from Estraier. Estraier was
* written by Mikio Hirabayashi.
* Copyright (C) 2003-2004 Mikio Hirabayashi
* The version where this comes from
* is covered by the GNU licence, as this file.*/
static const char *epairs[] = {
/* basic symbols */
"amp", "", "lt", "<", "gt", ">", "quot", "\"", "apos", "'",
/* ISO-8859-1 */
"nbsp", "\xc2\xa0", "iexcl", "\xc2\xa1", "cent", "\xc2\xa2",
"pound", "\xc2\xa3", "curren", "\xc2\xa4", "yen", "\xc2\xa5",
"brvbar", "\xc2\xa6", "sect", "\xc2\xa7", "uml", "\xc2\xa8",
"copy", "\xc2\xa9", "ordf", "\xc2\xaa", "laquo", "\xc2\xab",
"not", "\xc2\xac", "shy", "\xc2\xad", "reg", "\xc2\xae",
"macr", "\xc2\xaf", "deg", "\xc2\xb0", "plusmn", "\xc2\xb1",
"sup2", "\xc2\xb2", "sup3", "\xc2\xb3", "acute", "\xc2\xb4",
"micro", "\xc2\xb5", "para", "\xc2\xb6", "middot", "\xc2\xb7",
"cedil", "\xc2\xb8", "sup1", "\xc2\xb9", "ordm", "\xc2\xba",
"raquo", "\xc2\xbb", "frac14", "\xc2\xbc", "frac12", "\xc2\xbd",
"frac34", "\xc2\xbe", "iquest", "\xc2\xbf", "Agrave", "\xc3\x80",
"Aacute", "\xc3\x81", "Acirc", "\xc3\x82", "Atilde", "\xc3\x83",
"Auml", "\xc3\x84", "Aring", "\xc3\x85", "AElig", "\xc3\x86",
"Ccedil", "\xc3\x87", "Egrave", "\xc3\x88", "Eacute", "\xc3\x89",
"Ecirc", "\xc3\x8a", "Euml", "\xc3\x8b", "Igrave", "\xc3\x8c",
"Iacute", "\xc3\x8d", "Icirc", "\xc3\x8e", "Iuml", "\xc3\x8f",
"ETH", "\xc3\x90", "Ntilde", "\xc3\x91", "Ograve", "\xc3\x92",
"Oacute", "\xc3\x93", "Ocirc", "\xc3\x94", "Otilde", "\xc3\x95",
"Ouml", "\xc3\x96", "times", "\xc3\x97", "Oslash", "\xc3\x98",
"Ugrave", "\xc3\x99", "Uacute", "\xc3\x9a", "Ucirc", "\xc3\x9b",
"Uuml", "\xc3\x9c", "Yacute", "\xc3\x9d", "THORN", "\xc3\x9e",
"szlig", "\xc3\x9f", "agrave", "\xc3\xa0", "aacute", "\xc3\xa1",
"acirc", "\xc3\xa2", "atilde", "\xc3\xa3", "auml", "\xc3\xa4",
"aring", "\xc3\xa5", "aelig", "\xc3\xa6", "ccedil", "\xc3\xa7",
"egrave", "\xc3\xa8", "eacute", "\xc3\xa9", "ecirc", "\xc3\xaa",
"euml", "\xc3\xab", "igrave", "\xc3\xac", "iacute", "\xc3\xad",
"icirc", "\xc3\xae", "iuml", "\xc3\xaf", "eth", "\xc3\xb0",
"ntilde", "\xc3\xb1", "ograve", "\xc3\xb2", "oacute", "\xc3\xb3",
"ocirc", "\xc3\xb4", "otilde", "\xc3\xb5", "ouml", "\xc3\xb6",
"divide", "\xc3\xb7", "oslash", "\xc3\xb8", "ugrave", "\xc3\xb9",
"uacute", "\xc3\xba", "ucirc", "\xc3\xbb", "uuml", "\xc3\xbc",
"yacute", "\xc3\xbd", "thorn", "\xc3\xbe", "yuml", "\xc3\xbf",
/* ISO-10646 */
"fnof", "\xc6\x92", "Alpha", "\xce\x91", "Beta", "\xce\x92",
"Gamma", "\xce\x93", "Delta", "\xce\x94", "Epsilon", "\xce\x95",
"Zeta", "\xce\x96", "Eta", "\xce\x97", "Theta", "\xce\x98",
"Iota", "\xce\x99", "Kappa", "\xce\x9a", "Lambda", "\xce\x9b",
"Mu", "\xce\x9c", "Nu", "\xce\x9d", "Xi", "\xce\x9e",
"Omicron", "\xce\x9f", "Pi", "\xce\xa0", "Rho", "\xce\xa1",
"Sigma", "\xce\xa3", "Tau", "\xce\xa4", "Upsilon", "\xce\xa5",
"Phi", "\xce\xa6", "Chi", "\xce\xa7", "Psi", "\xce\xa8",
"Omega", "\xce\xa9", "alpha", "\xce\xb1", "beta", "\xce\xb2",
"gamma", "\xce\xb3", "delta", "\xce\xb4", "epsilon", "\xce\xb5",
"zeta", "\xce\xb6", "eta", "\xce\xb7", "theta", "\xce\xb8",
"iota", "\xce\xb9", "kappa", "\xce\xba", "lambda", "\xce\xbb",
"mu", "\xce\xbc", "nu", "\xce\xbd", "xi", "\xce\xbe",
"omicron", "\xce\xbf", "pi", "\xcf\x80", "rho", "\xcf\x81",
"sigmaf", "\xcf\x82", "sigma", "\xcf\x83", "tau", "\xcf\x84",
"upsilon", "\xcf\x85", "phi", "\xcf\x86", "chi", "\xcf\x87",
"psi", "\xcf\x88", "omega", "\xcf\x89", "thetasym", "\xcf\x91",
"upsih", "\xcf\x92", "piv", "\xcf\x96", "bull", "\xe2\x80\xa2",
"hellip", "\xe2\x80\xa6", "prime", "\xe2\x80\xb2", "Prime", "\xe2\x80\xb3",
"oline", "\xe2\x80\xbe", "frasl", "\xe2\x81\x84", "weierp", "\xe2\x84\x98",
"image", "\xe2\x84\x91", "real", "\xe2\x84\x9c", "trade", "\xe2\x84\xa2",
"alefsym", "\xe2\x84\xb5", "larr", "\xe2\x86\x90", "uarr", "\xe2\x86\x91",
"rarr", "\xe2\x86\x92", "darr", "\xe2\x86\x93", "harr", "\xe2\x86\x94",
"crarr", "\xe2\x86\xb5", "lArr", "\xe2\x87\x90", "uArr", "\xe2\x87\x91",
"rArr", "\xe2\x87\x92", "dArr", "\xe2\x87\x93", "hArr", "\xe2\x87\x94",
"forall", "\xe2\x88\x80", "part", "\xe2\x88\x82", "exist", "\xe2\x88\x83",
"empty", "\xe2\x88\x85", "nabla", "\xe2\x88\x87", "isin", "\xe2\x88\x88",
"notin", "\xe2\x88\x89", "ni", "\xe2\x88\x8b", "prod", "\xe2\x88\x8f",
"sum", "\xe2\x88\x91", "minus", "\xe2\x88\x92", "lowast", "\xe2\x88\x97",
"radic", "\xe2\x88\x9a", "prop", "\xe2\x88\x9d", "infin", "\xe2\x88\x9e",
"ang", "\xe2\x88\xa0", "and", "\xe2\x88\xa7", "or", "\xe2\x88\xa8",
"cap", "\xe2\x88\xa9", "cup", "\xe2\x88\xaa", "int", "\xe2\x88\xab",
"there4", "\xe2\x88\xb4", "sim", "\xe2\x88\xbc", "cong", "\xe2\x89\x85",
"asymp", "\xe2\x89\x88", "ne", "\xe2\x89\xa0", "equiv", "\xe2\x89\xa1",
"le", "\xe2\x89\xa4", "ge", "\xe2\x89\xa5", "sub", "\xe2\x8a\x82",
"sup", "\xe2\x8a\x83", "nsub", "\xe2\x8a\x84", "sube", "\xe2\x8a\x86",
"supe", "\xe2\x8a\x87", "oplus", "\xe2\x8a\x95", "otimes", "\xe2\x8a\x97",
"perp", "\xe2\x8a\xa5", "sdot", "\xe2\x8b\x85", "lceil", "\xe2\x8c\x88",
"rceil", "\xe2\x8c\x89", "lfloor", "\xe2\x8c\x8a", "rfloor", "\xe2\x8c\x8b",
"lang", "\xe2\x8c\xa9", "rang", "\xe2\x8c\xaa", "loz", "\xe2\x97\x8a",
"spades", "\xe2\x99\xa0", "clubs", "\xe2\x99\xa3", "hearts", "\xe2\x99\xa5",
"diams", "\xe2\x99\xa6", "OElig", "\xc5\x92", "oelig", "\xc5\x93",
"Scaron", "\xc5\xa0", "scaron", "\xc5\xa1", "Yuml", "\xc5\xb8",
"circ", "\xcb\x86", "tilde", "\xcb\x9c", "ensp", "\xe2\x80\x82",
"emsp", "\xe2\x80\x83", "thinsp", "\xe2\x80\x89", "zwnj", "\xe2\x80\x8c",
"zwj", "\xe2\x80\x8d", "lrm", "\xe2\x80\x8e", "rlm", "\xe2\x80\x8f",
"ndash", "\xe2\x80\x93", "mdash", "\xe2\x80\x94", "lsquo", "\xe2\x80\x98",
"rsquo", "\xe2\x80\x99", "sbquo", "\xe2\x80\x9a", "ldquo", "\xe2\x80\x9c",
"rdquo", "\xe2\x80\x9d", "bdquo", "\xe2\x80\x9e", "dagger", "\xe2\x80\xa0",
"Dagger", "\xe2\x80\xa1", "permil", "\xe2\x80\xb0", "lsaquo", "\xe2\x80\xb9",
"rsaquo", "\xe2\x80\xba", "euro", "\xe2\x82\xac",
NULL, NULL
};
HtmlParser::HtmlParser()
{
if (named_ents.empty()) {
for (int i = 0;;) {
const char *ent;
const char *val;
ent = epairs[i++];
if (ent == 0)
break;
val = epairs[i++];
if (val == 0)
break;
named_ents[string(ent)] = val;
}
}
}
void
HtmlParser::decode_entities(string &s)
{
// This has no meaning whatsoever if the character encoding is unknown,
// so don't do it. If charset known, caller has converted text to utf-8,
// and this is also how we translate entities
// if (charset != "utf-8")
// return;
// We need a const_iterator version of s.end() - otherwise the
// find() and find_if() templates don't work...
string::const_iterator amp = s.begin(), s_end = s.end();
while ((amp = find(amp, s_end, '&')) != s_end) {
unsigned int val = 0;
string::const_iterator end, p = amp + 1;
string subs;
if (p != s_end && *p == '#') {
p++;
if (p != s_end && tolower(*p) == 'x') {
// hex
p++;
end = find_if(p, s_end, p_notxdigit);
sscanf(s.substr(p - s.begin(), end - p).c_str(), "%x", &val);
} else {
// number
end = find_if(p, s_end, p_notdigit);
val = atoi(s.substr(p - s.begin(), end - p).c_str());
}
} else {
end = find_if(p, s_end, p_notalnum);
string code = s.substr(p - s.begin(), end - p);
map<string, string>::const_iterator i;
i = named_ents.find(code);
if (i != named_ents.end())
subs = i->second;
}
if (end < s_end && *end == ';')
end++;
if (val) {
// The code is the code position for a unicode char. We need
// to translate it to an utf-8 string.
string utf16be;
utf16be += char(val / 256);
utf16be += char(val % 256);
transcode(utf16be, subs, "UTF-16BE", "UTF-8");
}
if (subs.length() > 0) {
string::size_type amp_pos = amp - s.begin();
s.replace(amp_pos, end - amp, subs);
s_end = s.end();
// We've modified the string, so the iterators are no longer
// valid...
amp = s.begin() + amp_pos + subs.length();
} else {
amp = end;
}
}
}
void
HtmlParser::parse_html(const string &body)
{
map<string,string> Param;
string::const_iterator start = body.begin();
while (1) {
// Skip through until we find an HTML tag, a comment, or the end of
// document. Ignore isolated occurences of `<' which don't start
// a tag or comment
string::const_iterator p = start;
while (1) {
p = find(p, body.end(), '<');
if (p == body.end()) break;
char ch = *(p + 1);
// tag, closing tag, comment (or SGML declaration), or PHP
if (isalpha(ch) || ch == '/' || ch == '!' || ch == '?') break;
p++;
}
// process text up to start of tag
if (p > start) {
string text = body.substr(start - body.begin(), p - start);
decode_entities(text);
process_text(text);
}
if (p == body.end()) break;
start = p + 1;
if (start == body.end()) break;
if (*start == '!') {
if (++start == body.end()) break;
if (++start == body.end()) break;
// comment or SGML declaration
if (*(start - 1) == '-' && *start == '-') {
start = find(start + 1, body.end(), '>');
// unterminated comment swallows rest of document
// (like NS, but unlike MSIE iirc)
if (start == body.end()) break;
p = start;
// look for -->
while (p != body.end() && (*(p - 1) != '-' || *(p - 2) != '-'))
p = find(p + 1, body.end(), '>');
// If we found --> skip to there, otherwise
// skip to the first > we found (as Netscape does)
if (p != body.end()) start = p;
} else {
// just an SGML declaration, perhaps giving the DTD - ignore it
start = find(start - 1, body.end(), '>');
if (start == body.end()) break;
}
++start;
} else if (*start == '?') {
if (++start == body.end()) break;
// PHP - swallow until ?> or EOF
start = find(start + 1, body.end(), '>');
// look for ?>
while (start != body.end() && *(start - 1) != '?')
start = find(start + 1, body.end(), '>');
// unterminated PHP swallows rest of document (rather arbitrarily
// but it avoids polluting the database when things go wrong)
if (start != body.end()) ++start;
} else {
// opening or closing tag
int closing = 0;
if (*start == '/') {
closing = 1;
start = find_if(start + 1, body.end(), p_notwhitespace);
}
p = start;
start = find_if(start, body.end(), p_nottag);
string tag = body.substr(p - body.begin(), start - p);
// convert tagname to lowercase
for (string::iterator i = tag.begin(); i != tag.end(); i++)
*i = tolower(*i);
if (closing) {
closing_tag(tag);
/* ignore any bogus parameters on closing tags */
p = find(start, body.end(), '>');
if (p == body.end()) break;
start = p + 1;
} else {
while (start < body.end() && *start != '>') {
string name, value;
p = find_if(start, body.end(), p_whitespaceeqgt);
name = body.substr(start - body.begin(), p - start);
p = find_if(p, body.end(), p_notwhitespace);
start = p;
if (start != body.end() && *start == '=') {
int quote;
start = find_if(start + 1, body.end(), p_notwhitespace);
p = body.end();
quote = *start;
if (quote == '"' || quote == '\'') {
start++;
p = find(start, body.end(), quote);
}
if (p == body.end()) {
// unquoted or no closing quote
p = find_if(start, body.end(), p_whitespacegt);
value = body.substr(start - body.begin(), p - start);
start = find_if(p, body.end(), p_notwhitespace);
} else {
value = body.substr(start - body.begin(), p - start);
}
if (name.size()) {
// convert parameter name to lowercase
string::iterator i;
for (i = name.begin(); i != name.end(); i++)
*i = tolower(*i);
// in case of multiple entries, use the first
// (as Netscape does)
if (Param.find(name) == Param.end())
Param[name] = value;
}
}
}
opening_tag(tag, Param);
Param.clear();
if (start != body.end() && *start == '>') ++start;
}
}
}
}