WIP: more complete checking of names in code; re psychopy#1132

Unresolved:
- warning msg not printed on first param page (basic params), but does show for advanced params (e.g., text - flip)
  and does properly disable OK button for for error on basic params pages
  ?? somewhere `parent.nameOKlabel.SetLabel(message)` is getting lost / obscured / pre-empted??
- only attempted for a few specific fields:        elif fieldName in ('text', 'color', 'image', 'flip', 'opacity')
- need to think through more whether names from compiled code is always appropriate
  (and whether to always flag all namespace collisions)

psychopy/app/builder/dialogs/__init__.py

@@ -235,9 +235,12 @@ def __init__(self, dlg, label, param, parent, fieldName,
         if len(param.allowedVals) == 1 or param.readOnly:
             self.valueCtrl.Disable()  # visible but can't be changed
 
-        # add a NameValidator to name valueCtrl
+        # add a Validator to the valueCtrl
         if fieldName == "name":
             self.valueCtrl.SetValidator(validators.NameValidator())
+        elif fieldName in ('text', 'color', 'image', 'flip', 'opacity'):
+            # ... and anything that is valType code, or can be with $ ...
+            self.valueCtrl.SetValidator(validators.CodeValidator())
 
         # create the type control
         if len(param.allowedTypes):
@@ -682,8 +685,11 @@ def addParam(self, fieldName, parent, sizer, currRow, advanced=False,
                            advanced=advanced, appPrefs=self.app.prefs)
         self.paramCtrls[fieldName] = ctrls
         if fieldName == 'name':
-            ctrls.valueCtrl.Bind(wx.EVT_TEXT, self.checkName)
+            ctrls.valueCtrl.Bind(wx.EVT_TEXT, self.doValidate)
             ctrls.valueCtrl.SetFocus()
+        elif fieldName in ('text', 'color', 'image', 'flip', 'opacity'):
+            ctrls.valueCtrl.Bind(wx.EVT_TEXT, self.doValidate)
+
         # self.valueCtrl = self.typeCtrl = self.updateCtrl
         _flag = wx.ALIGN_RIGHT | wx.ALIGN_CENTRE_VERTICAL | wx.LEFT | wx.RIGHT
         sizer.Add(ctrls.nameCtrl, (currRow, 0), border=5, flag=_flag)
@@ -775,7 +781,7 @@ def show(self):
             self.OKbtn.Bind(wx.EVT_BUTTON, self.onOK)
         self.OKbtn.SetDefault()
 
-        self.checkName()  # disables OKbtn if bad name
+        self.doValidate()  # disables OKbtn if bad name
         buttons.Add(self.OKbtn, 0, wx.ALL, border=3)
         CANCEL = wx.Button(self, wx.ID_CANCEL, _translate(" Cancel "))
         buttons.Add(CANCEL, 0, wx.ALL, border=3)
@@ -1019,8 +1025,8 @@ def _checkName(self, event=None, name=None):
             else:
                 return "", True
 
-    def checkName(self, event=None):
-        """Issue a form validation on name change.
+    def doValidate(self, event=None):
+        """Issue a form validation on event, e.g., name or text change.
         """
         self.Validate()
 
@@ -1168,7 +1174,7 @@ def makeGlobalCtrls(self):
                            flag=wx.EXPAND | wx.ALIGN_CENTRE_VERTICAL | wx.ALL)
             row += 1
 
-        self.globalCtrls['name'].valueCtrl.Bind(wx.EVT_TEXT, self.checkName)
+        self.globalCtrls['name'].valueCtrl.Bind(wx.EVT_TEXT, self.doValidate)
         self.Bind(wx.EVT_CHOICE, self.onTypeChanged,
                   self.globalCtrls['loopType'].valueCtrl)
         return panel

psychopy/app/builder/validators.py

@@ -3,23 +3,24 @@
 '''
 import wx
 from ..localization import _translate
+from . import experiment
 
 
-class NameValidator(wx.PyValidator):
+class BaseValidator(wx.PyValidator):
     """
-    Component name validator for _BaseParamsDlg class. It depends on accesss
+    Component name validator for _BaseParamsDlg class. It depends on access
     to an experiment namespace. Validation checks if it is a valid Python
     identifier and if it does not clash with existing names.
 
     @see: _BaseParamsDlg
     """
 
     def __init__(self):
-        super(NameValidator, self).__init__()
+        super(BaseValidator, self).__init__()
         self.message = ""
 
     def Clone(self):
-        return NameValidator()
+        return self.__class__()
 
     def Validate(self, parent):
         """
@@ -31,7 +32,7 @@ def Validate(self, parent):
                 parent = parent.GetParent()
             except Exception:
                 print("Couldn't find the root dialog for this event")
-        message, valid = self.checkName(parent)
+        message, valid = self.check(parent)
         parent.nameOKlabel.SetLabel(message)
         return valid
 
@@ -41,7 +42,15 @@ def TransferFromWindow(self):
     def TransferToWindow(self):
         return True
 
-    def checkName(self, parent):
+    def check(self, parent):
+        raise NotImplementedError
+
+
+class NameValidator(BaseValidator):
+    def __init__(self):
+        super(NameValidator, self).__init__()
+
+    def check(self, parent):
         """checks namespace, return error-msg (str), enable (bool)
         """
         control = self.GetWindow()
@@ -65,3 +74,42 @@ def checkName(self, parent):
                 return msg, True
             else:
                 return "", True
+
+
+class CodeValidator(BaseValidator):
+    """
+    Component code validator for _BaseParamsDlg class. It depends on access
+    to an experiment namespace. Validation checks if it is a valid Python
+    code, and if so, whether it contains identifiers that clash with
+    existing names (in the to-be-generated python script).
+
+    @see: _BaseParamsDlg
+    """
+
+    def __init__(self):
+        super(CodeValidator, self).__init__()
+
+    def check(self, parent):
+        """checks intersection of names in code and namespace
+        """
+        control = self.GetWindow()
+        if not hasattr(control, 'GetValue'):
+            return '', True
+        val = control.GetValue()  # same as parent.params[self.fieldName].val
+        codeWanted = experiment._unescapedDollarSign_re.search(val)
+        if codeWanted:  # ... or valType == 'code' -- require fieldName?
+            # get var names from val, check against namespace:
+            code = experiment.getCodeFromParamStr(val)
+            try:
+                names = compile(code, '', 'eval').co_names
+            except SyntaxError:
+                pass
+            else:
+                namespace = parent.frame.exp.namespace
+                for name in names:
+                    # params['name'] not in namespace yet if its a new param
+                    if (name == parent.params['name'].val or
+                            namespace.exists(name)):
+                        msg = _translate('Name `{}` is already used')
+                        return msg.format(name), False
+        return '', True