diff -r 058bb3dc685f -r 0b59724cb3f2 cubicweb/ext/tal.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cubicweb/ext/tal.py	Sat Jan 16 13:48:51 2016 +0100
@@ -0,0 +1,273 @@
+# copyright 2003-2012 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This file is part of CubicWeb.
+#
+# CubicWeb is free software: you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
+"""provides simpleTAL extensions for CubicWeb
+
+"""
+
+__docformat__ = "restructuredtext en"
+
+import sys
+import re
+from os.path import exists, isdir, join
+from logging import getLogger
+from StringIO import StringIO
+
+from simpletal import simpleTAL, simpleTALES
+
+from logilab.common.decorators import cached
+
+LOGGER = getLogger('cubicweb.tal')
+
+
+class LoggerAdapter(object):
+    def __init__(self, tal_logger):
+        self.tal_logger = tal_logger
+
+    def debug(self, msg):
+        LOGGER.debug(msg)
+
+    def warn(self, msg):
+        LOGGER.warning(msg)
+
+    def __getattr__(self, attrname):
+        return getattr(self.tal_logger, attrname)
+
+
+class CubicWebContext(simpleTALES.Context):
+    """add facilities to access entity / resultset"""
+
+    def __init__(self, options=None, allowPythonPath=1):
+        simpleTALES.Context.__init__(self, options, allowPythonPath)
+        self.log = LoggerAdapter(self.log)
+
+    def update(self, context):
+        for varname, value in context.items():
+            self.addGlobal(varname, value)
+
+    def addRepeat(self, name, var, initialValue):
+        simpleTALES.Context.addRepeat(self, name, var, initialValue)
+
+# XXX FIXME need to find a clean to define OPCODE values for extensions
+I18N_CONTENT = 18
+I18N_REPLACE = 19
+RQL_EXECUTE  = 20
+# simpleTAL uses the OPCODE values to define priority over commands.
+# TAL_ITER should have the same priority than TAL_REPEAT (i.e. 3), but
+# we can't use the same OPCODE for two different commands without changing
+# the simpleTAL implementation. Another solution would be to totally override
+# the REPEAT implementation with the ITER one, but some specific operations
+# (involving len() for instance) are not implemented for ITER, so we prefer
+# to keep both implementations for now, and to fool simpleTAL by using a float
+# number between 3 and 4
+TAL_ITER     = 3.1
+
+
+# FIX simpleTAL HTML 4.01 stupidity
+# (simpleTAL never closes tags like INPUT, IMG, HR ...)
+simpleTAL.HTML_FORBIDDEN_ENDTAG.clear()
+
+class CubicWebTemplateCompiler(simpleTAL.HTMLTemplateCompiler):
+    """extends default compiler by adding i18n:content commands"""
+
+    def __init__(self):
+        simpleTAL.HTMLTemplateCompiler.__init__(self)
+        self.commandHandler[I18N_CONTENT] = self.compile_cmd_i18n_content
+        self.commandHandler[I18N_REPLACE] = self.compile_cmd_i18n_replace
+        self.commandHandler[RQL_EXECUTE] = self.compile_cmd_rql
+        self.commandHandler[TAL_ITER] = self.compile_cmd_tal_iter
+
+    def setTALPrefix(self, prefix):
+        simpleTAL.TemplateCompiler.setTALPrefix(self, prefix)
+        self.tal_attribute_map['i18n:content'] = I18N_CONTENT
+        self.tal_attribute_map['i18n:replace'] = I18N_REPLACE
+        self.tal_attribute_map['rql:execute'] = RQL_EXECUTE
+        self.tal_attribute_map['tal:iter'] = TAL_ITER
+
+    def compile_cmd_i18n_content(self, argument):
+        # XXX tal:content structure=, text= should we support this ?
+        structure_flag = 0
+        return (I18N_CONTENT, (argument, False, structure_flag, self.endTagSymbol))
+
+    def compile_cmd_i18n_replace(self, argument):
+        # XXX tal:content structure=, text= should we support this ?
+        structure_flag = 0
+        return (I18N_CONTENT, (argument, True, structure_flag, self.endTagSymbol))
+
+    def compile_cmd_rql(self, argument):
+        return (RQL_EXECUTE, (argument, self.endTagSymbol))
+
+    def compile_cmd_tal_iter(self, argument):
+        original_id, (var_name, expression, end_tag_symbol) = \
+                     simpleTAL.HTMLTemplateCompiler.compileCmdRepeat(self, argument)
+        return (TAL_ITER, (var_name, expression, self.endTagSymbol))
+
+    def getTemplate(self):
+        return CubicWebTemplate(self.commandList, self.macroMap, self.symbolLocationTable)
+
+    def compileCmdAttributes (self, argument):
+        """XXX modified to support single attribute
+        definition ending by a ';'
+
+        backport this to simpleTAL
+        """
+        # Compile tal:attributes into attribute command
+        # Argument: [(attributeName, expression)]
+
+        # Break up the list of attribute settings first
+        commandArgs = []
+        # We only want to match semi-colons that are not escaped
+        argumentSplitter =  re.compile(r'(?<!;);(?!;)')
+        for attributeStmt in argumentSplitter.split(argument):
+            if not attributeStmt.strip():
+                continue
+            #  remove any leading space and un-escape any semi-colons
+            attributeStmt = attributeStmt.lstrip().replace(';;', ';')
+            # Break each attributeStmt into name and expression
+            stmtBits = attributeStmt.split(' ')
+            if (len (stmtBits) < 2):
+                # Error, badly formed attributes command
+                msg = "Badly formed attributes command '%s'.  Attributes commands must be of the form: 'name expression[;name expression]'" % argument
+                self.log.error(msg)
+                raise simpleTAL.TemplateParseException(self.tagAsText(self.currentStartTag), msg)
+            attName = stmtBits[0]
+            attExpr = " ".join(stmtBits[1:])
+            commandArgs.append((attName, attExpr))
+        return (simpleTAL.TAL_ATTRIBUTES, commandArgs)
+
+
+class CubicWebTemplateInterpreter(simpleTAL.TemplateInterpreter):
+    """provides implementation for interpreting cubicweb extensions"""
+    def __init__(self):
+        simpleTAL.TemplateInterpreter.__init__(self)
+        self.commandHandler[I18N_CONTENT] = self.cmd_i18n
+        self.commandHandler[TAL_ITER] = self.cmdRepeat
+        # self.commandHandler[RQL_EXECUTE] = self.cmd_rql
+
+    def cmd_i18n(self, command, args):
+        """i18n:content and i18n:replace implementation"""
+        string, replace_flag, structure_flag, end_symbol = args
+        if replace_flag:
+            self.outputTag = 0
+        result = self.context.globals['_'](string)
+        self.tagContent = (0, result)
+        self.movePCForward = self.symbolTable[end_symbol]
+        self.programCounter += 1
+
+
+class CubicWebTemplate(simpleTAL.HTMLTemplate):
+    """overrides HTMLTemplate.expand() to systematically use CubicWebInterpreter
+    """
+    def expand(self, context, outputFile):
+        interpreter = CubicWebTemplateInterpreter()
+        interpreter.initialise(context, outputFile)
+        simpleTAL.HTMLTemplate.expand(self, context, outputFile,# outputEncoding='unicode',
+                                      interpreter=interpreter)
+
+    def expandInline(self, context, outputFile, interpreter):
+        """ Internally used when expanding a template that is part of a context."""
+        try:
+            interpreter.execute(self)
+        except UnicodeError as unierror:
+            LOGGER.exception(str(unierror))
+            exc = simpleTALES.ContextContentException(
+                "found non-unicode %r string in Context!" % unierror.args[1])
+            exc.__traceback__ = sys.exc_info()[-1]
+            raise exc
+
+
+def compile_template(template):
+    """compiles a TAL template string
+    :type template: unicode
+    :param template: a TAL-compliant template string
+    """
+    string_buffer = StringIO(template)
+    compiler = CubicWebTemplateCompiler()
+    compiler.parseTemplate(string_buffer) # , inputEncoding='unicode')
+    return compiler.getTemplate()
+
+
+def compile_template_file(filepath):
+    """compiles a TAL template file
+    :type filepath: str
+    :param template: path of the file to compile
+    """
+    fp = open(filepath)
+    file_content = unicode(fp.read()) # template file should be pure ASCII
+    fp.close()
+    return compile_template(file_content)
+
+
+def evaluatePython (self, expr):
+    if not self.allowPythonPath:
+        return self.false
+    globals = {}
+    for name, value in self.globals.items():
+        if isinstance (value, simpleTALES.ContextVariable):
+            value = value.rawValue()
+        globals[name] = value
+    globals['path'] = self.pythonPathFuncs.path
+    globals['string'] = self.pythonPathFuncs.string
+    globals['exists'] = self.pythonPathFuncs.exists
+    globals['nocall'] = self.pythonPathFuncs.nocall
+    globals['test'] = self.pythonPathFuncs.test
+    locals = {}
+    for name, value in self.locals.items():
+        if (isinstance (value, simpleTALES.ContextVariable)):
+            value = value.rawValue()
+        locals[name] = value
+    # XXX precompile expr will avoid late syntax error
+    try:
+        result = eval(expr, globals, locals)
+    except Exception as ex:
+        ex = ex.__class__('in %r: %s' % (expr, ex))
+        ex.__traceback__ = sys.exc_info()[-1]
+        raise ex
+    if (isinstance (result, simpleTALES.ContextVariable)):
+        return result.value()
+    return result
+
+simpleTALES.Context.evaluatePython = evaluatePython
+
+
+class talbased(object):
+    def __init__(self, filename, write=True):
+##         if not osp.isfile(filepath):
+##             # print "[tal.py] just for tests..."
+##             # get parent frame
+##             directory = osp.abspath(osp.dirname(sys._getframe(1).f_globals['__file__']))
+##             filepath = osp.join(directory, filepath)
+        self.filename = filename
+        self.write = write
+
+    def __call__(self, viewfunc):
+        def wrapped(instance, *args, **kwargs):
+            variables = viewfunc(instance, *args, **kwargs)
+            html = instance.tal_render(self._compiled_template(instance), variables)
+            if self.write:
+                instance.w(html)
+            else:
+                return html
+        return wrapped
+
+    def _compiled_template(self, instance):
+        for fileordirectory in instance.config.appobjects_path():
+            filepath = join(fileordirectory, self.filename)
+            if isdir(fileordirectory) and exists(filepath):
+                return compile_template_file(filepath)
+        raise Exception('no such template %s' % self.filename)
+    _compiled_template = cached(_compiled_template, 0)