##############################################################################
#
# Copyright (c) 2001, 2002 Zope Corporation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""
Parse HTML and compile to TALInterpreter intermediate code.
"""
import sys
from TALGenerator import TALGenerator
from HTMLParser import HTMLParser,HTMLParseError
from TALDefs import \
ZOPE_METAL_NS, ZOPE_TAL_NS, ZOPE_I18N_NS, METALError, TALError, I18NError
BOOLEAN_HTML_ATTRS = [
# List of Boolean attributes in HTML that may be given in
# minimized form (e.g. <img ismap> rather than <img ismap="">)
# From http://www.w3.org/TR/xhtml1/#guidelines (C.10)
"compact", "nowrap", "ismap", "declare", "noshade", "checked",
"disabled", "readonly", "multiple", "selected", "noresize",
"defer"
]
EMPTY_HTML_TAGS = [
# List of HTML tags with an empty content model; these are
# rendered in minimized form, e.g. <img />.
# From http://www.w3.org/TR/xhtml1/#dtds
"base", "meta", "link", "hr", "br", "param", "img", "area",
"input", "col", "basefont", "isindex", "frame",
]
PARA_LEVEL_HTML_TAGS = [
# List of HTML elements that close open paragraph-level elements
# and are themselves paragraph-level.
"h1", "h2", "h3", "h4", "h5", "h6", "p",
]
BLOCK_CLOSING_TAG_MAP = {
"tr": ("tr", "td", "th"),
"td": ("td", "th"),
"th": ("td", "th"),
"li": ("li",),
"dd": ("dd", "dt"),
"dt": ("dd", "dt"),
}
BLOCK_LEVEL_HTML_TAGS = [
# List of HTML tags that denote larger sections than paragraphs.
"blockquote", "table", "tr", "th", "td", "thead", "tfoot", "tbody",
"noframe", "ul", "ol", "li", "dl", "dt", "dd", "div",
]
TIGHTEN_IMPLICIT_CLOSE_TAGS = (PARA_LEVEL_HTML_TAGS
+ BLOCK_CLOSING_TAG_MAP.keys())
class NestingError(HTMLParseError):
"""Exception raised when elements aren't properly nested."""
def __init__(self, tagstack, endtag, position=(None, None)):
self.endtag = endtag
if tagstack:
if len(tagstack) == 1:
msg = ('Open tag <%s> does not match close tag </%s>'
% (tagstack[0], endtag))
else:
msg = ('Open tags <%s> do not match close tag </%s>'
% ('>, <'.join(tagstack), endtag))
else:
msg = 'No tags are open to match </%s>' % endtag
HTMLParseError.__init__(self, msg, position)
class EmptyTagError(NestingError):
"""Exception raised when empty elements have an end tag."""
def __init__(self, tag, position=(None, None)):
self.tag = tag
msg = 'Close tag </%s> should be removed' % tag
HTMLParseError.__init__(self, msg, position)
class OpenTagError(NestingError):
"""Exception raised when a tag is not allowed in another tag."""
def __init__(self, tagstack, tag, position=(None, None)):
self.tag = tag
msg = 'Tag <%s> is not allowed in <%s>' % (tag, tagstack[-1])
HTMLParseError.__init__(self, msg, position)
class HTMLTALParser(HTMLParser):
# External API
def __init__(self, gen=None):
HTMLParser.__init__(self)
if gen is None:
gen = TALGenerator(xml=0)
self.gen = gen
self.tagstack = []
self.nsstack = []
self.nsdict = {'tal': ZOPE_TAL_NS,
'metal': ZOPE_METAL_NS,
'i18n': ZOPE_I18N_NS,
}
def parseFile(self, file):
f = open(file)
data = f.read()
f.close()
try:
self.parseString(data)
except TALError, e:
e.setFile(file)
raise
def parseString(self, data):
self.feed(data)
self.close()
while self.tagstack:
self.implied_endtag(self.tagstack[-1], 2)
assert self.nsstack == [], self.nsstack
def getCode(self):
return self.gen.getCode()
def getWarnings(self):
return ()
# Overriding HTMLParser methods
def handle_starttag(self, tag, attrs):
self.close_para_tags(tag)
self.scan_xmlns(attrs)
tag, attrlist, taldict, metaldict, i18ndict \
= self.process_ns(tag, attrs)
self.tagstack.append(tag)
self.gen.emitStartElement(tag, attrlist, taldict, metaldict, i18ndict,
self.getpos())
if tag in EMPTY_HTML_TAGS:
self.implied_endtag(tag, -1)
def handle_startendtag(self, tag, attrs):
self.close_para_tags(tag)
self.scan_xmlns(attrs)
tag, attrlist, taldict, metaldict, i18ndict \
= self.process_ns(tag, attrs)
if taldict.get("content"):
self.gen.emitStartElement(tag, attrlist, taldict, metaldict,
i18ndict, self.getpos())
self.gen.emitEndElement(tag, implied=-1)
else:
self.gen.emitStartElement(tag, attrlist, taldict, metaldict,
i18ndict, self.getpos(), isend=1)
self.pop_xmlns()
def handle_endtag(self, tag):
if tag in EMPTY_HTML_TAGS:
# </img> etc. in the source is an error
raise EmptyTagError(tag, self.getpos())
self.close_enclosed_tags(tag)
self.gen.emitEndElement(tag)
self.pop_xmlns()
self.tagstack.pop()
def close_para_tags(self, tag):
if tag in EMPTY_HTML_TAGS:
return
close_to = -1
if BLOCK_CLOSING_TAG_MAP.has_key(tag):
blocks_to_close = BLOCK_CLOSING_TAG_MAP[tag]
for i in range(len(self.tagstack)):
t = self.tagstack[i]
if t in blocks_to_close:
if close_to == -1:
close_to = i
elif t in BLOCK_LEVEL_HTML_TAGS:
close_to = -1
elif tag in PARA_LEVEL_HTML_TAGS + BLOCK_LEVEL_HTML_TAGS:
i = len(self.tagstack) - 1
while i >= 0:
closetag = self.tagstack[i]
if closetag in BLOCK_LEVEL_HTML_TAGS:
break
if closetag in PARA_LEVEL_HTML_TAGS:
if closetag != "p":
raise OpenTagError(self.tagstack, tag, self.getpos())
close_to = i
i = i - 1
if close_to >= 0:
while len(self.tagstack) > close_to:
self.implied_endtag(self.tagstack[-1], 1)
def close_enclosed_tags(self, tag):
if tag not in self.tagstack:
raise NestingError(self.tagstack, tag, self.getpos())
while tag != self.tagstack[-1]:
self.implied_endtag(self.tagstack[-1], 1)
assert self.tagstack[-1] == tag
def implied_endtag(self, tag, implied):
assert tag == self.tagstack[-1]
assert implied in (-1, 1, 2)
isend = (implied < 0)
if tag in TIGHTEN_IMPLICIT_CLOSE_TAGS:
# Pick out trailing whitespace from the program, and
# insert the close tag before the whitespace.
white = self.gen.unEmitWhitespace()
else:
white = None
self.gen.emitEndElement(tag, isend=isend, implied=implied)
if white:
self.gen.emitRawText(white)
self.tagstack.pop()
self.pop_xmlns()
def handle_charref(self, name):
self.gen.emitRawText("&#%s;" % name)
def handle_entityref(self, name):
self.gen.emitRawText("&%s;" % name)
def handle_data(self, data):
self.gen.emitRawText(data)
def handle_comment(self, data):
self.gen.emitRawText("<!--%s-->" % data)
def handle_decl(self, data):
self.gen.emitRawText("<!%s>" % data)
def handle_pi(self, data):
self.gen.emitRawText("<?%s>" % data)
# Internal thingies
def scan_xmlns(self, attrs):
nsnew = {}
for key, value in attrs:
if key.startswith("xmlns:"):
nsnew[key[6:]] = value
if nsnew:
self.nsstack.append(self.nsdict)
self.nsdict = self.nsdict.copy()
self.nsdict.update(nsnew)
else:
self.nsstack.append(self.nsdict)
def pop_xmlns(self):
self.nsdict = self.nsstack.pop()
def fixname(self, name):
if ':' in name:
prefix, suffix = name.split(':', 1)
if prefix == 'xmlns':
nsuri = self.nsdict.get(suffix)
if nsuri in (ZOPE_TAL_NS, ZOPE_METAL_NS, ZOPE_I18N_NS):
return name, name, prefix
else:
nsuri = self.nsdict.get(prefix)
if nsuri == ZOPE_TAL_NS:
return name, suffix, 'tal'
elif nsuri == ZOPE_METAL_NS:
return name, suffix, 'metal'
elif nsuri == ZOPE_I18N_NS:
return name, suffix, 'i18n'
return name, name, 0
def process_ns(self, name, attrs):
attrlist = []
taldict = {}
metaldict = {}
i18ndict = {}
name, namebase, namens = self.fixname(name)
for item in attrs:
key, value = item
key, keybase, keyns = self.fixname(key)
ns = keyns or namens # default to tag namespace
if ns and ns != 'unknown':
item = (key, value, ns)
if ns == 'tal':
if taldict.has_key(keybase):
raise TALError("duplicate TAL attribute " +
`keybase`, self.getpos())
taldict[keybase] = value
elif ns == 'metal':
if metaldict.has_key(keybase):
raise METALError("duplicate METAL attribute " +
`keybase`, self.getpos())
metaldict[keybase] = value
elif ns == 'i18n':
if i18ndict.has_key(keybase):
raise I18NError("duplicate i18n attribute " +
`keybase`, self.getpos())
i18ndict[keybase] = value
attrlist.append(item)
if namens in ('metal', 'tal'):
taldict['tal tag'] = namens
return name, attrlist, taldict, metaldict, i18ndict
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