[Tutor] How does this work?

[Kent Johnson]

Kent Johnson wrote:
> You should be able to make the logging module work with you, it is very 
> flexible. You should hook into the logging module. Write a custom 
> handler that pushes log methods into your GUI. Add the handler to the 
> root logger.

Here is a simple, working example of this. It creates a custom log 
handler that logs to a wx.TextCtrl and sets up the logging module to log 
to the custom handler and also to the console.

This is pretty much my first wx program and I whipped it together *very* 
quickly (mostly copy-and-paste from the "wxPython in Action" sample 
code) so no points for style, but it does work. Every time you click the 
button it will generate a log event.

Kent


import logging, wx, sys

class LogToText(logging.Handler):
     def __init__(self, textCtl):
         logging.Handler.__init__(self)
         self.textCtl = textCtl

     def emit(self, record):
         self.textCtl.AppendText(self.format(record))
         self.textCtl.AppendText('\n')


class TextFrame(wx.Frame):

     def __init__(self):
         wx.Frame.__init__(self, None, -1, 'Text Entry Example',
                 size=(300, 250))
         panel = wx.Panel(self, -1)
         multiLabel = wx.StaticText(panel, -1, "Multi-line")
         self.multiText = wx.TextCtrl(panel, -1,
                "",
                size=(200, 100), style=wx.TE_MULTILINE)
         self.multiText.SetInsertionPoint(0)

         self.button = wx.Button(panel, -1, "Click Me")
         self.Bind(wx.EVT_BUTTON, self.OnClick, self.button)
         self.button.SetDefault()

         sizer = wx.FlexGridSizer(cols=2, hgap=6, vgap=6)
         sizer.AddMany([multiLabel, self.multiText, self.button])
         panel.SetSizer(sizer)

     def OnClick(self, event):
         logging.error("Clicked")

if __name__ == '__main__':
     app = wx.PySimpleApp()
     frame = TextFrame()


     handler = LogToText(frame.multiText)
     logger=logging.getLogger()
     logger.addHandler(handler)

     stdout_handler = logging.StreamHandler(sys.stdout)
     formatter = logging.Formatter('%(name)s :%(asctime)s %(filename)s 
%(lineno)s %(levelname)s  %(message)s')
     stdout_handler.setFormatter(formatter)
     logger.addHandler(stdout_handler)

     frame.Show()
     app.MainLoop()