Mercurial > p > roundup > code
view roundup/cgi/TAL/TALParser.py @ 5630:07abc8d36940
Add etag support to rest interface to prevent multiple users from
overwriting other users changes.
All GET requests for an object (issue, user, keyword etc.) or a
property of an object (e.g the title of an issue) return the etag for
the object in the ETag header as well as the @etag field in the
returned object.
All requests that change existing objects (DELETE, PUT or PATCH)
require:
1 A request include an ETag header with the etag value retrieved
for the object.
2 A submits a form that includes the field @etag that must have
the value retrieved for the object.
If an etag is not supplied by one of these methods, or any supplied
etag does not match the etag calculated at the time the DELETE, PUT or
PATCH request is made, HTTP error 412 (Precondition Failed) is
returned and no change is made. At that time the client code should
retrieve the object again, reconcile the changes and can try to send a
new update.
The etag is the md5 hash of the representation (repr()) of the object
retrieved from the database.
| author | John Rouillard <rouilj@ieee.org> |
|---|---|
| date | Fri, 01 Mar 2019 22:57:07 -0500 |
| parents | 23b8e6067f7c |
| children |
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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()
