Merge 49037e8 into b541ca9

CHANGES.rst

@@ -5,6 +5,10 @@
 5.2.0 (unreleased)
 ==================
 
+- ``tales.Context.getValue`` now returns the innermost (not outermost)
+  value for the given variable. Fixes
+  `#19 <https://github.com/zopefoundation/zope.tales/issues/19>`_.
+
 - Add support for Python 3.9, 3.10.
 
 - Fix error message raised if the first element of a path expression is not

src/zope/tales/tales.py

@@ -744,12 +744,16 @@ def setGlobal(self, name, value):
             vars[name] = value
 
     def getValue(self, name, default=None):
-        value = default
-        for vars in self._vars_stack:
-            value = vars.get(name, default)
-            if value is not default:
-                break
-        return value
+        """return the current value of variable *name* or *default*."""
+        # ``beginScope`` puts a copy of all variables into ``vars``
+        #  and pushes it onto ``_vars_stack``,
+        # ``endScope`` pops the last element of ``vars_stack`` into ``vars``,
+        # ``setGlobal`` updates all variable bindings in ``_vars_stack``
+        # (and thereby, implicitly, ``vars``).
+        # Consequently, the current value of a variable can
+        # always be found in ``vars``
+        # (no need to iterate over ``_vars_stack``).
+        return self.vars.get(name, default)
 
     def setRepeat(self, name, expr):
         expr = self.evaluate(expr)

src/zope/tales/tests/test_tales.py

@@ -134,21 +134,27 @@ def testVariables(self):
 
         c = ctxt.vars
         self.assertEqual(c['v1'], 1, 'Variable "v1"')
+        self.assertEqual(ctxt.getValue('v1'), 1, 'Variable "v1"')
 
         ctxt.beginScope()
         ctxt.setLocal('v1', 3)
         ctxt.setGlobal('g', 1)
 
         c = ctxt.vars
         self.assertEqual(c['v1'], 3, 'Inner scope')
+        self.assertEqual(ctxt.getValue('v1'), 3, 'Inner scope')
         self.assertEqual(c['v2'], 2, 'Outer scope')
+        self.assertEqual(ctxt.getValue('v2'), 2, 'Outer scope')
         self.assertEqual(c['g'], 1, 'Global')
+        self.assertEqual(ctxt.getValue('g'), 1, 'Global')
 
         ctxt.endScope()
 
         c = ctxt.vars
         self.assertEqual(c['v1'], 1, "Uncovered local")
+        self.assertEqual(ctxt.getValue('v1'), 1, "Uncovered local")
         self.assertEqual(c['g'], 1, "Global from inner scope")
+        self.assertEqual(ctxt.getValue('g'), 1, "Global from inner scope")
 
         ctxt.endScope()
 
@@ -220,7 +226,7 @@ def test_getValue_nested(self):
         self.context.vars['it'] = 1
         self.context.beginScope()
         self.context.vars['it'] = 2
-        self.assertEqual(self.context.getValue('it'), 1)
+        self.assertEqual(self.context.getValue('it'), 2)
 
     def test_evaluate_boolean(self):
         # Make sure it always returns a regular bool, no matter