wxPython dialogs: How to validate inputs in multiple controls? - validation

Question

I have a wx.Dialog with several input fields. When the OK button is pressed I want to run validations such as:
If one of three fields is filled in, all three must be filled in.
If a radiobutton is set, then it's corresponding field must not be empty.
I know about the normal validators that get attached to a control with wx.Window.SetValidator(). But these just validate the content of their respective control.
I tried attaching a validator to the wx.Dialog, but this is not called unfortunately.
I tried binding the event from the ID_OK button to a handler to do the validation there, but the result is that the dialog doesn't close anymore.
What is the proper way to do this kind of validation?
Below is my code with what I tried:
import wx
class DialogValidator(wx.Validator):
def Clone(self):
return DialogValidator()
def Validate(self, win):
print("this method is never called :-(")
field1 = win.field1.GetValue()
field2 = win.field2.GetValue()
field3 = win.field3.GetValue()
if len(field1) > 0 or len(field2) > 0 or len(field3) > 0:
# if one of these is filled in, all three must
if len(field1) == 0 or len(field2) == 0 or len(field3) == 0:
wx.MessageBox("All three fields must be filled in!", "Error")
return False
return True
def TransferToWindow(self):
return True
def TransferFromWindow(self):
return True
class MyDialog(wx.Dialog):
def __init__(self, *args, **kwds):
wx.Dialog.__init__(self, *args, **kwds)
self.field1 = wx.TextCtrl(self, wx.ID_ANY, "")
self.field2 = wx.TextCtrl(self, wx.ID_ANY, "")
self.field3 = wx.TextCtrl(self, wx.ID_ANY, "")
self.radio1 = wx.RadioButton(self, wx.ID_ANY, "radio1", style=wx.RB_GROUP)
self.radio2 = wx.RadioButton(self, wx.ID_ANY, "radio2")
self.dialog_btn_sizer = wx.StdDialogButtonSizer()
self.dialog_btn_sizer.AddButton(wx.Button(self, wx.ID_OK))
self.dialog_btn_sizer.AddButton(wx.Button(self, wx.ID_CANCEL))
self.dialog_btn_sizer.Realize()
main_sizer = wx.BoxSizer(wx.VERTICAL)
main_sizer.Add(self.radio1)
main_sizer.Add(self.radio2)
main_sizer.Add(self.field1)
main_sizer.Add(self.field2)
main_sizer.Add(self.field3)
main_sizer.Add(self.dialog_btn_sizer, 0, wx.EXPAND, 0)
self.SetSizer(main_sizer)
main_sizer.Fit(self)
self.Layout()
self.SetValidator(DialogValidator()) # doesn't work unfortunately
self.Bind(wx.EVT_BUTTON, self.on_ok, id=wx.ID_OK) # doesn't work either
def on_ok(self, event):
field1 = self.field1.GetValue()
field2 = self.field2.GetValue()
field3 = self.field3.GetValue()
if len(field1) > 0 or len(field2) > 0 or len(field3) > 0:
# if one of these is filled in, all three must
if len(field1) == 0 or len(field2) == 0 or len(field3) == 0:
wx.MessageBox("All three fields must be filled in!", "Error")
event.Skip()
return
# Note that I do NOT call event.Skip() here!
# I was hoping the original handler would pick up the event
# and properly close the dialog -> unfortunately this is not the case
print("inputs fine, now the dialog should get closed")

Answer 1

I now solved it by setting a validator on one field that accesses the other fields by going over the dialog. I found out that win in wx.Validator.Validate(self, win) refers to the underlying wx.Dialog.
(Why handling the ID_OK button didn't work I don't know, but this would be another question.)
I'm posting my solution in the hope it helps others struggling with validators:
import wx
class FieldValidator(wx.Validator):
def Clone(self):
return FieldValidator()
def Validate(self, win):
# 'win' refers to the dialog,
# so I can access the other controls like this:
field1 = win.field1.GetValue()
field2 = win.field2.GetValue()
field3 = win.field3.GetValue()
# btw: with self.GetWindow() I can get the control being validated
if len(field1) > 0 or len(field2) > 0 or len(field3) > 0:
# if one of these is filled in, all three must
if len(field1) == 0 or len(field2) == 0 or len(field3) == 0:
wx.MessageBox("All three fields must be filled in!", "Error")
return False
return True
def TransferToWindow(self):
return True
def TransferFromWindow(self):
return True
class MyDialog(wx.Dialog):
def __init__(self, *args, **kwds):
wx.Dialog.__init__(self, *args, **kwds)
self.field1 = wx.TextCtrl(self, wx.ID_ANY, "")
self.field2 = wx.TextCtrl(self, wx.ID_ANY, "")
self.field3 = wx.TextCtrl(self, wx.ID_ANY, "")
self.radio1 = wx.RadioButton(self, wx.ID_ANY, "radio1", style=wx.RB_GROUP)
self.radio2 = wx.RadioButton(self, wx.ID_ANY, "radio2")
self.dialog_btn_sizer = wx.StdDialogButtonSizer()
self.dialog_btn_sizer.AddButton(wx.Button(self, wx.ID_OK))
self.dialog_btn_sizer.AddButton(wx.Button(self, wx.ID_CANCEL))
self.dialog_btn_sizer.Realize()
main_sizer = wx.BoxSizer(wx.VERTICAL)
main_sizer.Add(self.radio1)
main_sizer.Add(self.radio2)
main_sizer.Add(self.field1)
main_sizer.Add(self.field2)
main_sizer.Add(self.field3)
main_sizer.Add(self.dialog_btn_sizer, 0, wx.EXPAND, 0)
self.SetSizer(main_sizer)
main_sizer.Fit(self)
self.Layout()
self.field1.SetValidator(FieldValidator())