[Checkins] SVN: five.pt/trunk/ Added path and exists functions.

[Malthe Borch]

Log message for revision 93033:
  Added path and exists functions.

Changed:
  U   five.pt/trunk/CHANGES.txt
  U   five.pt/trunk/src/five/pt/cmf.py
  U   five.pt/trunk/src/five/pt/pagetemplate.py

-=-
Modified: five.pt/trunk/CHANGES.txt
===================================================================
--- five.pt/trunk/CHANGES.txt	2008-11-17 03:18:13 UTC (rev 93032)
+++ five.pt/trunk/CHANGES.txt	2008-11-17 03:42:20 UTC (rev 93033)
@@ -4,6 +4,9 @@
 HEAD
 ----
 
+- Added ``path`` and ``exists`` functions to skin template
+  namespace. [malthe]
+
 - Added call-support for old-style classes in path
   expressions. [malthe]
 

Modified: five.pt/trunk/src/five/pt/cmf.py
===================================================================
--- five.pt/trunk/src/five/pt/cmf.py	2008-11-17 03:18:13 UTC (rev 93032)
+++ five.pt/trunk/src/five/pt/cmf.py	2008-11-17 03:42:20 UTC (rev 93033)
@@ -1,4 +1,3 @@
-import sys
 import Globals
 
 from Products.CMFCore.FSObject import FSObject
@@ -15,34 +14,10 @@
 
 from pagetemplate import PageTemplateFile
 from pagetemplate import FiveTemplateFile
+from pagetemplate import EContext
 
 _marker = object()
 
-class EContext(object):
-    """This class emulates the `econtext` variable scope dictionary of
-    ZPT; it uses `sys._getframe` to acquire the variable and adds
-    required methods."""
-    
-    _scope = None
-
-    @property
-    def vars(self):
-        if self._scope is None:
-            frame = sys._getframe()
-            scope = _marker
-            while scope is _marker and frame is not None:
-                scope = frame.f_locals.get('_scope', _marker)
-                frame = frame.f_back
-            if vars is _marker:
-                raise RuntimeError, 'Context not found'
-            self._scope = scope
-        return self._scope
-        
-    def setLocal(self, name, value):
-        self.vars[name] = value
-
-    setGlobal = setLocal
-    
 class CMFTemplateFile(FiveTemplateFile):
     @property
     def utility_builtins(self):

Modified: five.pt/trunk/src/five/pt/pagetemplate.py
===================================================================
--- five.pt/trunk/src/five/pt/pagetemplate.py	2008-11-17 03:18:13 UTC (rev 93032)
+++ five.pt/trunk/src/five/pt/pagetemplate.py	2008-11-17 03:42:20 UTC (rev 93033)
@@ -1,21 +1,103 @@
 import os
 import sys
 
+from zope import component
 from zope.app.pagetemplate.viewpagetemplatefile import ViewMapper
 
 from Acquisition import aq_get
 from Acquisition import aq_inner
 from Acquisition import aq_parent
 
+from AccessControl import getSecurityManager
+
 from Products.PageTemplates.Expressions import SecureModuleImporter
 
 from z3c.pt import pagetemplate
 
+from chameleon.core import types
+from chameleon.core import config
+from chameleon.core import clauses
+from chameleon.core import generation
+from chameleon.zpt.interfaces import IExpressionTranslator
+
+from five.pt.expressions import path_translator
+
+_marker = object()
+_expr_cache = {}
+
 def get_physical_root(context):
     method = aq_get(context, 'getPhysicalRoot', None)
     if method is not None:
         return method()
 
+def evaluate_expression(pragma, expr):
+    key = "%s(%s)" % (pragma, expr)
+    cache = getattr(_expr_cache, key, _marker)
+    if cache is not _marker:
+        symbol_mapping, parts, source = cache
+    else:
+        translator = component.getUtility(IExpressionTranslator, name=pragma)
+        parts = translator.tales(expr)
+        stream = generation.CodeIO(symbols=config.SYMBOLS)
+        assign = clauses.Assign(parts, 'result')
+        assign.begin(stream)
+        assign.end(stream)
+        source = stream.getvalue()
+
+        symbol_mapping = parts.symbol_mapping.copy()
+        if isinstance(parts, types.parts):
+            for value in parts:
+                symbol_mapping.update(value.symbol_mapping)    
+
+        _expr_cache[key] = symbol_mapping, parts, source
+
+    # acquire template locals and update with symbol mapping
+    _locals = EContext().locals
+    _locals.update(symbol_mapping)    
+
+    # execute code and return evaluation
+    exec source in _locals
+    return _locals['result']
+
+def evaluate_path(expr):
+    return evaluate_expression('path', expr)
+
+def evaluate_exists(expr):
+    return evaluate_expression('exists', expr)
+
+class EContext(object):
+    """This class emulates the `econtext` variable scope dictionary of
+    ZPT; it uses `sys._getframe` to acquire the variable and adds
+    required methods."""
+    
+    _scope = None
+    _locals = None
+
+    @property
+    def locals(self):
+        self.vars; return self._locals
+        
+    @property
+    def vars(self):
+        if self._scope is None:
+            frame = sys._getframe()
+            scope = _marker
+            while frame is not None:
+                scope = frame.f_locals.get('_scope', _marker)
+                if scope is not _marker:
+                    self._locals = frame.f_locals
+                    break
+                frame = frame.f_back
+            else:
+                raise RuntimeError, "Can't locate variable scope."
+            self._scope = scope
+        return self._scope
+        
+    def setLocal(self, name, value):
+        self.vars[name] = value
+
+    setGlobal = setLocal
+        
 class FiveTemplateFile(pagetemplate.PageTemplateFile.template_class):
     utility_builtins = {}
 
@@ -48,7 +130,10 @@
                 here=context,
                 container=context,
                 nothing=None,
+                path=evaluate_path,
+                exists=evaluate_exists,
                 root=root,
+                user=getSecurityManager().getUser(),
                 modules=SecureModuleImporter,
                 options=kwargs)