view roundup/cgi/TAL/TALParser.py @ 5414:3fa026621f69

Python 3 preparation: comparisons. Python 3 no longer has the cmp function, or cmp= arguments to sorting functions / methods (key= must be used instead), and requires rich comparison methods such as __lt__ to be defined instead of using __cmp__. All of the comparison mechanisms supported in Python 3 are also supported in Python 2. This patch makes the corresponding changes in Roundup to use key functions and rich comparison methods. In the case of the JournalPassword and Permission classes, only __eq__ and __ne__ are defined as I don't see ordered comparisons as useful there (and for Permission, the old __cmp__ function didn't try to provide a valid ordering). In the case of the Date class, I kept the __cmp__ method and implemented the others in terms of it, to avoid excess repetitiveness in duplicating implementation code for all six rich comparison methods. In roundup/admin.py, help_commands_html used operator.attrgetter to produce the second argument of sorted() - which would be reasonable for a key function, but the second argument is the cmp function in Python 2, not a key function (and the key function must be a named argument not a positional argument in Python 3). That function appears to be completely unused, so I expect that code never worked. This patch adds the missing key= to that sorted() call, but it would also be reasonable to remove the unused function completely instead.
author Joseph Myers <jsm@polyomino.org.uk>
date Wed, 25 Jul 2018 00:39:37 +0000
parents 23b8e6067f7c
children
line wrap: on
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##############################################################################
#
# 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 XML and compile to TALInterpreter intermediate code.
"""

from .XMLParser import XMLParser
from .TALDefs import XML_NS, ZOPE_I18N_NS, ZOPE_METAL_NS, ZOPE_TAL_NS
from .TALGenerator import TALGenerator

class TALParser(XMLParser):

    ordered_attributes = 1

    def __init__(self, gen=None): # Override
        XMLParser.__init__(self)
        if gen is None:
            gen = TALGenerator()
        self.gen = gen
        self.nsStack = []
        self.nsDict = {XML_NS: 'xml'}
        self.nsNew = []

    def getCode(self):
        return self.gen.getCode()

    def getWarnings(self):
        return ()

    def StartNamespaceDeclHandler(self, prefix, uri):
        self.nsStack.append(self.nsDict.copy())
        self.nsDict[uri] = prefix
        self.nsNew.append((prefix, uri))

    def EndNamespaceDeclHandler(self, prefix):
        self.nsDict = self.nsStack.pop()

    def StartElementHandler(self, name, attrs):
        if self.ordered_attributes:
            # attrs is a list of alternating names and values
            attrlist = []
            for i in range(0, len(attrs), 2):
                key = attrs[i]
                value = attrs[i+1]
                attrlist.append((key, value))
        else:
            # attrs is a dict of {name: value}
            attrlist = sorted(attrs.items()) # Sorted for definiteness
        name, attrlist, taldict, metaldict, i18ndict \
              = self.process_ns(name, attrlist)
        attrlist = self.xmlnsattrs() + attrlist
        self.gen.emitStartElement(name, attrlist, taldict, metaldict, i18ndict)

    def process_ns(self, name, attrlist):
        taldict = {}
        metaldict = {}
        i18ndict = {}
        fixedattrlist = []
        name, namebase, namens = self.fixname(name)
        for key, value in attrlist:
            key, keybase, keyns = self.fixname(key)
            ns = keyns or namens # default to tag namespace
            item = key, value
            if ns == 'metal':
                metaldict[keybase] = value
                item = item + ("metal",)
            elif ns == 'tal':
                taldict[keybase] = value
                item = item + ("tal",)
            elif ns == 'i18n':
                assert 0, "dealing with i18n: " + repr((keybase, value))
                i18ndict[keybase] = value
                item = item + ('i18n',)
            fixedattrlist.append(item)
        if namens in ('metal', 'tal', 'i18n'):
            taldict['tal tag'] = namens
        return name, fixedattrlist, taldict, metaldict, i18ndict

    def xmlnsattrs(self):
        newlist = []
        for prefix, uri in self.nsNew:
            if prefix:
                key = "xmlns:" + prefix
            else:
                key = "xmlns"
            if uri in (ZOPE_METAL_NS, ZOPE_TAL_NS, ZOPE_I18N_NS):
                item = (key, uri, "xmlns")
            else:
                item = (key, uri)
            newlist.append(item)
        self.nsNew = []
        return newlist

    def fixname(self, name):
        if ' ' in name:
            uri, name = name.split(' ')
            prefix = self.nsDict[uri]
            prefixed = name
            if prefix:
                prefixed = "%s:%s" % (prefix, name)
            ns = 'x'
            if uri == ZOPE_TAL_NS:
                ns = 'tal'
            elif uri == ZOPE_METAL_NS:
                ns = 'metal'
            elif uri == ZOPE_I18N_NS:
                ns = 'i18n'
            return (prefixed, name, ns)
        return (name, name, None)

    def EndElementHandler(self, name):
        name = self.fixname(name)[0]
        self.gen.emitEndElement(name)

    def DefaultHandler(self, text):
        self.gen.emitRawText(text)

def test():
    import sys
    p = TALParser()
    file = "tests/input/test01.xml"
    if sys.argv[1:]:
        file = sys.argv[1]
    p.parseFile(file)
    program, macros = p.getCode()
    from .TALInterpreter import TALInterpreter
    from .DummyEngine import DummyEngine
    engine = DummyEngine(macros)
    TALInterpreter(program, macros, engine, sys.stdout, wrap=0)()

if __name__ == "__main__":
    test()

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