--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/roundup/cgi/TAL/HTMLParser.py	Thu Sep 05 00:37:09 2002 +0000
@@ -0,0 +1,403 @@
+"""A parser for HTML and XHTML."""
+
+# This file is based on sgmllib.py, but the API is slightly different.
+
+# XXX There should be a way to distinguish between PCDATA (parsed
+# character data -- the normal case), RCDATA (replaceable character
+# data -- only char and entity references and end tags are special)
+# and CDATA (character data -- only end tags are special).
+
+
+import markupbase
+import re
+import string
+
+# Regular expressions used for parsing
+
+interesting_normal = re.compile('[&<]')
+interesting_cdata = re.compile(r'<(/|\Z)')
+incomplete = re.compile('&[a-zA-Z#]')
+
+entityref = re.compile('&([a-zA-Z][-.a-zA-Z0-9]*)[^a-zA-Z0-9]')
+charref = re.compile('&#(?:[0-9]+|[xX][0-9a-fA-F]+)[^0-9a-fA-F]')
+
+starttagopen = re.compile('<[a-zA-Z]')
+piclose = re.compile('>')
+endtagopen = re.compile('</')
+commentclose = re.compile(r'--\s*>')
+tagfind = re.compile('[a-zA-Z][-.a-zA-Z0-9:_]*')
+attrfind = re.compile(
+    r'\s*([a-zA-Z_][-.:a-zA-Z_0-9]*)(\s*=\s*'
+    r'(\'[^\']*\'|"[^"]*"|[-a-zA-Z0-9./:;+*%?!&$\(\)_#=~]*))?')
+
+locatestarttagend = re.compile(r"""
+  <[a-zA-Z][-.a-zA-Z0-9:_]*          # tag name
+  (?:\s+                             # whitespace before attribute name
+    (?:[a-zA-Z_][-.:a-zA-Z0-9_]*     # attribute name
+      (?:\s*=\s*                     # value indicator
+        (?:'[^']*'                   # LITA-enclosed value
+          |\"[^\"]*\"                # LIT-enclosed value
+          |[^'\">\s]+                # bare value
+         )
+       )?
+     )
+   )*
+  \s*                                # trailing whitespace
+""", re.VERBOSE)
+endendtag = re.compile('>')
+endtagfind = re.compile('</\s*([a-zA-Z][-.a-zA-Z0-9:_]*)\s*>')
+
+
+class HTMLParseError(Exception):
+    """Exception raised for all parse errors."""
+
+    def __init__(self, msg, position=(None, None)):
+        assert msg
+        self.msg = msg
+        self.lineno = position[0]
+        self.offset = position[1]
+
+    def __str__(self):
+        result = self.msg
+        if self.lineno is not None:
+            result = result + ", at line %d" % self.lineno
+        if self.offset is not None:
+            result = result + ", column %d" % (self.offset + 1)
+        return result
+
+
+def _contains_at(s, sub, pos):
+    return s[pos:pos+len(sub)] == sub
+
+
+class HTMLParser(markupbase.ParserBase):
+    """Find tags and other markup and call handler functions.
+
+    Usage:
+        p = HTMLParser()
+        p.feed(data)
+        ...
+        p.close()
+
+    Start tags are handled by calling self.handle_starttag() or
+    self.handle_startendtag(); end tags by self.handle_endtag().  The
+    data between tags is passed from the parser to the derived class
+    by calling self.handle_data() with the data as argument (the data
+    may be split up in arbitrary chunks).  Entity references are
+    passed by calling self.handle_entityref() with the entity
+    reference as the argument.  Numeric character references are
+    passed to self.handle_charref() with the string containing the
+    reference as the argument.
+    """
+
+    CDATA_CONTENT_ELEMENTS = ("script", "style")
+
+
+    def __init__(self):
+        """Initialize and reset this instance."""
+        self.reset()
+
+    def reset(self):
+        """Reset this instance.  Loses all unprocessed data."""
+        self.rawdata = ''
+        self.stack = []
+        self.lasttag = '???'
+        self.interesting = interesting_normal
+        markupbase.ParserBase.reset(self)
+
+    def feed(self, data):
+        """Feed data to the parser.
+
+        Call this as often as you want, with as little or as much text
+        as you want (may include '\n').
+        """
+        self.rawdata = self.rawdata + data
+        self.goahead(0)
+
+    def close(self):
+        """Handle any buffered data."""
+        self.goahead(1)
+
+    def error(self, message):
+        raise HTMLParseError(message, self.getpos())
+
+    __starttag_text = None
+
+    def get_starttag_text(self):
+        """Return full source of start tag: '<...>'."""
+        return self.__starttag_text
+
+    cdata_endtag = None
+
+    def set_cdata_mode(self, endtag=None):
+        self.cdata_endtag = endtag
+        self.interesting = interesting_cdata
+
+    def clear_cdata_mode(self):
+        self.cdata_endtag = None
+        self.interesting = interesting_normal
+
+    # Internal -- handle data as far as reasonable.  May leave state
+    # and data to be processed by a subsequent call.  If 'end' is
+    # true, force handling all data as if followed by EOF marker.
+    def goahead(self, end):
+        rawdata = self.rawdata
+        i = 0
+        n = len(rawdata)
+        while i < n:
+            match = self.interesting.search(rawdata, i) # < or &
+            if match:
+                j = match.start()
+            else:
+                j = n
+            if i < j: self.handle_data(rawdata[i:j])
+            i = self.updatepos(i, j)
+            if i == n: break
+            if rawdata[i] == '<':
+                if starttagopen.match(rawdata, i): # < + letter
+                    k = self.parse_starttag(i)
+                elif endtagopen.match(rawdata, i): # </
+                    k = self.parse_endtag(i)
+                elif _contains_at(rawdata, "<!--", i): # <!--
+                    k = self.parse_comment(i)
+                elif _contains_at(rawdata, "<!", i): # <!
+                    k = self.parse_declaration(i)
+                elif _contains_at(rawdata, "<?", i): # <?
+                    k = self.parse_pi(i)
+                elif _contains_at(rawdata, "<?", i): # <!
+                    k = self.parse_declaration(i)
+                elif (i + 1) < n:
+                    self.handle_data("<")
+                    k = i + 1
+                else:
+                    break
+                if k < 0:
+                    if end:
+                        self.error("EOF in middle of construct")
+                    break
+                i = self.updatepos(i, k)
+            elif rawdata[i:i+2] == "&#":
+                match = charref.match(rawdata, i)
+                if match:
+                    name = match.group()[2:-1]
+                    self.handle_charref(name)
+                    k = match.end()
+                    if rawdata[k-1] != ';':
+                        k = k - 1
+                    i = self.updatepos(i, k)
+                    continue
+                else:
+                    break
+            elif rawdata[i] == '&':
+                match = entityref.match(rawdata, i)
+                if match:
+                    name = match.group(1)
+                    self.handle_entityref(name)
+                    k = match.end()
+                    if rawdata[k-1] != ';':
+                        k = k - 1
+                    i = self.updatepos(i, k)
+                    continue
+                match = incomplete.match(rawdata, i)
+                if match:
+                    # match.group() will contain at least 2 chars
+                    rest = rawdata[i:]
+                    if end and match.group() == rest:
+                        self.error("EOF in middle of entity or char ref")
+                    # incomplete
+                    break
+                elif (i + 1) < n:
+                    # not the end of the buffer, and can't be confused
+                    # with some other construct
+                    self.handle_data("&")
+                    i = self.updatepos(i, i + 1)
+                else:
+                    break
+            else:
+                assert 0, "interesting.search() lied"
+        # end while
+        if end and i < n:
+            self.handle_data(rawdata[i:n])
+            i = self.updatepos(i, n)
+        self.rawdata = rawdata[i:]
+
+    # Internal -- parse comment, return end or -1 if not terminated
+    def parse_comment(self, i, report=1):
+        rawdata = self.rawdata
+        assert rawdata[i:i+4] == '<!--', 'unexpected call to parse_comment()'
+        match = commentclose.search(rawdata, i+4)
+        if not match:
+            return -1
+        if report:
+            j = match.start()
+            self.handle_comment(rawdata[i+4: j])
+        j = match.end()
+        return j
+
+    # Internal -- parse processing instr, return end or -1 if not terminated
+    def parse_pi(self, i):
+        rawdata = self.rawdata
+        assert rawdata[i:i+2] == '<?', 'unexpected call to parse_pi()'
+        match = piclose.search(rawdata, i+2) # >
+        if not match:
+            return -1
+        j = match.start()
+        self.handle_pi(rawdata[i+2: j])
+        j = match.end()
+        return j
+
+    # Internal -- handle starttag, return end or -1 if not terminated
+    def parse_starttag(self, i):
+        self.__starttag_text = None
+        endpos = self.check_for_whole_start_tag(i)
+        if endpos < 0:
+            return endpos
+        rawdata = self.rawdata
+        self.__starttag_text = rawdata[i:endpos]
+
+        # Now parse the data between i+1 and j into a tag and attrs
+        attrs = []
+        match = tagfind.match(rawdata, i+1)
+        assert match, 'unexpected call to parse_starttag()'
+        k = match.end()
+        self.lasttag = tag = string.lower(rawdata[i+1:k])
+
+        while k < endpos:
+            m = attrfind.match(rawdata, k)
+            if not m:
+                break
+            attrname, rest, attrvalue = m.group(1, 2, 3)
+            if not rest:
+                attrvalue = None
+            elif attrvalue[:1] == '\'' == attrvalue[-1:] or \
+                 attrvalue[:1] == '"' == attrvalue[-1:]:
+                attrvalue = attrvalue[1:-1]
+                attrvalue = self.unescape(attrvalue)
+            attrs.append((string.lower(attrname), attrvalue))
+            k = m.end()
+
+        end = string.strip(rawdata[k:endpos])
+        if end not in (">", "/>"):
+            lineno, offset = self.getpos()
+            if "\n" in self.__starttag_text:
+                lineno = lineno + string.count(self.__starttag_text, "\n")
+                offset = len(self.__starttag_text) \
+                         - string.rfind(self.__starttag_text, "\n")
+            else:
+                offset = offset + len(self.__starttag_text)
+            self.error("junk characters in start tag: %s"
+                       % `rawdata[k:endpos][:20]`)
+        if end[-2:] == '/>':
+            # XHTML-style empty tag: <span attr="value" />
+            self.handle_startendtag(tag, attrs)
+        else:
+            self.handle_starttag(tag, attrs)
+            if tag in self.CDATA_CONTENT_ELEMENTS:
+                self.set_cdata_mode(tag)
+        return endpos
+
+    # Internal -- check to see if we have a complete starttag; return end
+    # or -1 if incomplete.
+    def check_for_whole_start_tag(self, i):
+        rawdata = self.rawdata
+        m = locatestarttagend.match(rawdata, i)
+        if m:
+            j = m.end()
+            next = rawdata[j:j+1]
+            if next == ">":
+                return j + 1
+            if next == "/":
+                s = rawdata[j:j+2]
+                if s == "/>":
+                    return j + 2
+                if s == "/":
+                    # buffer boundary
+                    return -1
+                # else bogus input
+                self.updatepos(i, j + 1)
+                self.error("malformed empty start tag")
+            if next == "":
+                # end of input
+                return -1
+            if next in ("abcdefghijklmnopqrstuvwxyz=/"
+                        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"):
+                # end of input in or before attribute value, or we have the
+                # '/' from a '/>' ending
+                return -1
+            self.updatepos(i, j)
+            self.error("malformed start tag")
+        raise AssertionError("we should not get here!")
+
+    # Internal -- parse endtag, return end or -1 if incomplete
+    def parse_endtag(self, i):
+        rawdata = self.rawdata
+        assert rawdata[i:i+2] == "</", "unexpected call to parse_endtag"
+        match = endendtag.search(rawdata, i+1) # >
+        if not match:
+            return -1
+        j = match.end()
+        match = endtagfind.match(rawdata, i) # </ + tag + >
+        if not match:
+            self.error("bad end tag: %s" % `rawdata[i:j]`)
+        tag = string.lower(match.group(1))
+        if (  self.cdata_endtag is not None
+              and tag != self.cdata_endtag):
+            # Should be a mismatched end tag, but we'll treat it
+            # as text anyway, since most HTML authors aren't
+            # interested in the finer points of syntax.
+            self.handle_data(match.group(0))
+        else:
+            self.handle_endtag(tag)
+            self.clear_cdata_mode()
+        return j
+
+    # Overridable -- finish processing of start+end tag: <tag.../>
+    def handle_startendtag(self, tag, attrs):
+        self.handle_starttag(tag, attrs)
+        self.handle_endtag(tag)
+
+    # Overridable -- handle start tag
+    def handle_starttag(self, tag, attrs):
+        pass
+
+    # Overridable -- handle end tag
+    def handle_endtag(self, tag):
+        pass
+
+    # Overridable -- handle character reference
+    def handle_charref(self, name):
+        pass
+
+    # Overridable -- handle entity reference
+    def handle_entityref(self, name):
+        pass
+
+    # Overridable -- handle data
+    def handle_data(self, data):
+        pass
+
+    # Overridable -- handle comment
+    def handle_comment(self, data):
+        pass
+
+    # Overridable -- handle declaration
+    def handle_decl(self, decl):
+        pass
+
+    # Overridable -- handle processing instruction
+    def handle_pi(self, data):
+        pass
+
+    def unknown_decl(self, data):
+        self.error("unknown declaration: " + `data`)
+
+    # Internal -- helper to remove special character quoting
+    def unescape(self, s):
+        if '&' not in s:
+            return s
+        s = string.replace(s, "&lt;", "<")
+        s = string.replace(s, "&gt;", ">")
+        s = string.replace(s, "&apos;", "'")
+        s = string.replace(s, "&quot;", '"')
+        s = string.replace(s, "&amp;", "&") # Must be last
+        return s