Add the tal:omit_tag statement.

Make elements obey the XML rule: attributes without explicit namespaces are in the same namespace as the tag. As a corollary, TAL output with markup removed also removes tags that are in the TAL and METAL namespace.

lib/python/TAL/DummyEngine.py

@@ -104,7 +104,7 @@ class DummyEngine:
         if macros is None:
             macros = {}
         self.macros = macros
-        dict = {'nothing': None}
+        dict = {'nothing': None, 'default': Default}
         self.locals = self.globals = dict
         self.stack = [dict]
 
@@ -170,7 +170,7 @@ class DummyEngine:
 
     def evaluateText(self, expr):
         text = self.evaluate(expr)
-        if text is not None:
+        if text is not None and text is not Default:
             text = str(text)
         return text
 

lib/python/TAL/HTMLTALParser.py

@@ -192,9 +192,9 @@ class HTMLTALParser(HTMLParser):
 
     def handle_starttag(self, tag, attrs):
         self.close_para_tags(tag)
-        self.tagstack.append(tag)
         self.scan_xmlns(attrs)
-        attrlist, taldict, metaldict = self.extract_attrs(attrs)
+        tag, attrlist, taldict, metaldict = self.process_ns(tag, attrs)
+        self.tagstack.append(tag)
         self.gen.emitStartElement(tag, attrlist, taldict, metaldict,
                                   self.getpos())
         if tag in EMPTY_HTML_TAGS:
@@ -203,7 +203,7 @@ class HTMLTALParser(HTMLParser):
     def handle_startendtag(self, tag, attrs):
         self.close_para_tags(tag)
         self.scan_xmlns(attrs)
-        attrlist, taldict, metaldict = self.extract_attrs(attrs)
+        tag, attrlist, taldict, metaldict = self.process_ns(tag, attrs)
         if taldict.get("content"):
             self.gen.emitStartElement(tag, attrlist, taldict, metaldict,
                                       self.getpos())
@@ -304,29 +304,43 @@ class HTMLTALParser(HTMLParser):
     def pop_xmlns(self):
         self.nsdict = self.nsstack.pop()
 
-    def extract_attrs(self, attrs):
+    def fixname(self, name):
+        if ':' in name:
+            prefix, suffix = string.split(name, ':', 1)
+            if prefix == 'xmlns':
+                nsuri = self.nsdict.get(suffix)
+                if nsuri in (ZOPE_TAL_NS, ZOPE_METAL_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'
+        return name, name, 0
+
+    def process_ns(self, name, attrs):
         attrlist = []
         taldict = {}
         metaldict = {}
+        name, namebase, namens = self.fixname(name)
         for item in attrs:
             key, value = item
-            if ':' in key:
-                prefix, suffix = string.split(key, ':', 1)
-                nsuri = self.nsdict.get(prefix)
-                if nsuri == ZOPE_METAL_NS:
-                    if metaldict.has_key(suffix):
-                        raise METALError("duplicate METAL attribute " +
-                                         `suffix`, self.getpos())
-                    item = (key, value, "metal")
-                    metaldict[suffix] = value
-                elif nsuri == ZOPE_TAL_NS:
-                    if taldict.has_key(suffix):
-                        raise TALError("duplicate TAL attribute " +
-                                       `suffix`, self.getpos())
-                    item = (key, value, "tal")
-                    taldict[suffix] = value
-                elif (prefix == "xmlns" and
-                      value in (ZOPE_METAL_NS, ZOPE_TAL_NS)):
-                    item = (key, value, "xmlns")
+            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
             attrlist.append(item)
-        return attrlist, taldict, metaldict
+        if namens in ('metal', 'tal'):
+            taldict['tal tag'] = namens
+        return name, attrlist, taldict, metaldict

lib/python/TAL/TALDefs.py

@@ -113,6 +113,8 @@ KNOWN_TAL_ATTRIBUTES = [
     "repeat",
     "attributes",
     "on-error",
+    "omit-tag",
+    "tal tag",
     ]
 
 class TALError(Exception):

lib/python/TAL/TALGenerator.py

@@ -263,6 +263,18 @@ class TALGenerator:
         else:
             self.emit("endTag", name)
 
+    def emitOptTag(self, name, optTag, isend):
+        program = self.popProgram() #block
+        start = self.popProgram() #start tag
+        if (isend or not program) and self.xml:
+            # Minimize empty element
+            start[-1] = ("startEndTag",) + start[-1][1:]
+            isend = 1
+        cexpr = optTag[0]
+        if cexpr:
+            cexpr = self.compileExpression(optTag[0])
+        self.emit("optTag", name, cexpr, optTag[1], isend, start, program)
+        
     def emitRawText(self, text):
         self.emit("rawtext", text)
 
@@ -434,6 +446,8 @@ class TALGenerator:
         replace = taldict.get("replace")
         attrsubst = taldict.get("attributes")
         onError = taldict.get("on-error")
+        omitTag = taldict.get("omit-tag")
+        TALtag = taldict.get("tal tag")
         if len(metaldict) > 1 and (defineMacro or useMacro):
             raise METALError("define-macro and use-macro cannot be used "
                              "together or with define-slot or fill-slot",
@@ -492,6 +506,10 @@ class TALGenerator:
         if replace:
             todo["replace"] = replace
             self.pushProgram()
+        optTag = omitTag is not None or TALtag
+        if optTag:
+            todo["optional tag"] = omitTag, TALtag
+            self.pushProgram()
         if attrsubst:
             repldict = parseAttributeReplacements(attrsubst)
             for key, value in repldict.items():
@@ -502,6 +520,8 @@ class TALGenerator:
             todo["repldict"] = repldict
             repldict = {}
         self.emitStartTag(name, self.replaceAttrs(attrlist, repldict), isend)
+        if optTag:
+            self.pushProgram()
         if content:
             self.pushProgram()
         if todo and position != (None, None):
@@ -531,6 +551,7 @@ class TALGenerator:
         define = todo.get("define")
         repldict = todo.get("repldict", {})
         scope = todo.get("scope")
+        optTag = todo.get("optional tag")
 
         if implied > 0:
             if defineMacro or useMacro or defineSlot or fillSlot:
@@ -544,7 +565,9 @@ class TALGenerator:
 
         if content:
             self.emitSubstitution(content, {}, position)
-        if not isend:
+        if optTag:
+            self.emitOptTag(name, optTag, isend)
+        elif not isend:
             self.emitEndTag(name)
         if replace:
             self.emitSubstitution(replace, repldict, position)

lib/python/TAL/TALInterpreter.py

@@ -416,6 +416,35 @@ class TALInterpreter:
         return ok, name, value
     bytecode_handlers["<attrAction>"] = attrAction
 
+    def no_tag(self, start, program):
+        state = self.saveState()
+        self.stream = stream = StringIO()
+        self._stream_write = stream.write
+        self.interpret(start)
+        self.restoreOutputState(state)
+        self.interpret(program)
+
+    def do_optTag(self, (name, cexpr, tag_ns, isend, start, program),
+                  omit=0):
+        if tag_ns and not self.showtal:
+            return self.no_tag(start, program)
+            
+        self.interpret(start)
+        if not isend:
+            self.interpret(program)
+            s = '</%s>' % name
+            self._stream_write(s)
+            self.col = self.col + len(s)
+
+    def do_optTag_tal(self, stuff):
+        cexpr = stuff[1]
+        if cexpr is not None and (cexpr == '' or
+                                  self.engine.evaluateBoolean(cexpr)):
+            self.no_tag(stuff[-2], stuff[-1])
+        else:
+            self.do_optTag(stuff)
+    bytecode_handlers["optTag"] = do_optTag
+
     def dumpMacroStack(self, prefix, suffix, value):
         sys.stderr.write("+---- %s%s = %s\n" % (prefix, suffix, value))
         for i in range(len(self.macroStack)):
@@ -649,6 +678,7 @@ class TALInterpreter:
     bytecode_handlers_tal["loop"] = do_loop_tal
     bytecode_handlers_tal["onError"] = do_onError_tal
     bytecode_handlers_tal["<attrAction>"] = attrAction_tal
+    bytecode_handlers_tal["optTag"] = do_optTag_tal
 
 
 def test():

lib/python/TAL/TALParser.py

@@ -116,7 +116,6 @@ class TALParser(XMLParser):
         self.nsDict = self.nsStack.pop()
 
     def StartElementHandler(self, name, attrs):
-        name = self.fixname(name)
         if self.ordered_attributes:
             # attrs is a list of alternating names and values
             attrlist = []
@@ -128,28 +127,29 @@ class TALParser(XMLParser):
             # attrs is a dict of {name: value}
             attrlist = attrs.items()
             attrlist.sort() # For definiteness
-        attrlist, taldict, metaldict = self.extractattrs(attrlist)
+        name, attrlist, taldict, metaldict = self.process_ns(name, attrlist)
         attrlist = self.xmlnsattrs() + attrlist
         self.gen.emitStartElement(name, attrlist, taldict, metaldict)
 
-    def extractattrs(self, attrlist):
-        talprefix = ZOPE_TAL_NS + " "
-        ntal = len(talprefix)
-        metalprefix = ZOPE_METAL_NS + " "
-        nmetal = len(metalprefix)
+    def process_ns(self, name, attrlist):
         taldict = {}
         metaldict = {}
         fixedattrlist = []
+        name, namebase, namens = self.fixname(name)
         for key, value in attrlist:
-            item = self.fixname(key), value
-            if key[:nmetal] == metalprefix:
-                metaldict[key[nmetal:]] = value
+            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 key[:ntal] == talprefix:
-                taldict[key[ntal:]] = value
+            elif ns == 'tal':
+                taldict[keybase] = value
                 item = item + ("tal",)
             fixedattrlist.append(item)
-        return fixedattrlist, taldict, metaldict
+        if namens in ('metal', 'tal'):
+            taldict['tal tag'] = namens
+        return name, fixedattrlist, taldict, metaldict
 
     def xmlnsattrs(self):
         newlist = []
@@ -170,12 +170,19 @@ class TALParser(XMLParser):
         if ' ' in name:
             uri, name = string.split(name, ' ')
             prefix = self.nsDict[uri]
+            prefixed = name
             if prefix:
-                name = "%s:%s" % (prefix, name)
-        return name
+                prefixed = "%s:%s" % (prefix, name)
+            ns = 'x'
+            if uri == ZOPE_TAL_NS:
+                ns = 'tal'
+            elif uri == ZOPE_METAL_NS:
+                ns = 'metal'
+            return (prefixed, name, ns)
+        return (name, name, None)
 
     def EndElementHandler(self, name):
-        name = self.fixname(name)
+        name = self.fixname(name)[0]
         self.gen.emitEndElement(name)
 
     def DefaultHandler(self, text):

lib/python/TAL/tests/input/test17.html

+<tal:block tal:content="string:Yes">No</tal:block>
+<tal:block content="string:Yes">No</tal:block>
+<tal:block>Yes</tal:block>
+
+<metal:block tal:content="string:Yes">No</metal:block>
+<metal:block>Yes</metal:block>

lib/python/TAL/tests/input/test17.xml

+<?xml version="1.0"?>
+<body xmlns:z="http://xml.zope.org/namespaces/tal"
+      xmlns:z2="http://xml.zope.org/namespaces/metal">
+<z:block z:content="string:Yes">No</z:block>
+<z:block content="string:Yes">No</z:block>
+<z:block>Yes</z:block>
+
+<z2:block z:content="string:Yes">No</z2:block>
+<z2:block>Yes</z2:block>
+</body>

lib/python/TAL/tests/input/test18.html

+<p tal:omit-tag="">Content</p>
+<p tal:omit-tag=""></p>
+<img tal:omit-tag="">
+
+<p tal:omit-tag="string:Yes">Content</p>
+<p tal:omit-tag="string:Yes"></p>
+<img tal:omit-tag="string:Yes">
+
+<p tal:omit-tag="nothing">Content</p>
+<p tal:omit-tag="nothing"></p>
+<img tal:omit-tag="nothing">
+
+<p tal:define="txt string:Yes" tal:omit-tag="" tal:content="txt">No</p>
+<p tal:define="txt string:Yes" tal:omit-tag="" tal:replace="txt">No</p>
+<p tal:omit-tag="" tal:content="default">Yes</p>
+<p tal:omit-tag="" tal:replace="default">Yes</p>

lib/python/TAL/tests/input/test18.xml

+<?xml version="1.0"?>
+<body xmlns:tal="http://xml.zope.org/namespaces/tal"
+      xmlns:metal="http://xml.zope.org/namespaces/metal">
+<p tal:omit-tag="">Content</p>
+<p tal:omit-tag=""></p>
+<img tal:omit-tag=""/>
+
+<p tal:omit-tag="string:Yes">Content</p>
+<p tal:omit-tag="string:Yes"></p>
+<img tal:omit-tag="string:Yes"/>
+
+<p tal:omit-tag="nothing">Content</p>
+<p tal:omit-tag="nothing"></p>
+<img tal:omit-tag="nothing" />
+
+<p tal:define="txt string:Yes" tal:omit-tag="" tal:content="txt">No</p>
+<p tal:define="txt string:Yes" tal:omit-tag="" tal:replace="txt">No</p>
+<p tal:omit-tag="" tal:content="default">Yes</p>
+<p tal:omit-tag="" tal:replace="default">Yes</p>
+</body>

lib/python/TAL/tests/output/test17.html

+Yes
+Yes
+Yes
+
+Yes
+Yes

lib/python/TAL/tests/output/test17.xml

+<?xml version="1.0"?>
+<body>
+Yes
+Yes
+Yes
+
+Yes
+Yes
+</body>

lib/python/TAL/tests/output/test18.html

+Content
+
+
+
+Content
+
+
+
+<p>Content</p>
+<p></p>
+<img>
+
+Yes
+Yes
+Yes
+Yes

lib/python/TAL/tests/output/test18.xml

+<?xml version="1.0"?>
+<body>
+Content
+
+
+
+Content
+
+
+
+<p>Content</p>
+<p/>
+<img/>
+
+Yes
+Yes
+Yes
+Yes
+</body>