Wxpython Webview: How To Reload On Error?

I'm using wx.html2.WebView to load a Website in a Dialog, which is working fine. Problem: If the Website can't be reached for any reason, the output will be Could not connect: Conn

Solution 1:

There is something strange going on there! The only way that I could force it to work was to redefine the WebView each time. I may be being over zealous with the Destroy each time as well. This works but may not necessarily be exactly what you are after.

import wx
import wx.html2
import time

URL = "http://mydomain.tld"classMyBrowser(wx.Frame):
    def__init__(self, *args, **kwds):
        wx.Frame.__init__(self, *args, **kwds)
        self.url = URL
        self.browser = wx.html2.WebView.New(self, -1, size=(900,600))
        self.browser.Bind(wx.html2.EVT_WEBVIEW_ERROR, self.on_webview_error)
        self.browser.Bind(wx.html2.EVT_WEBVIEW_LOADED, self.on_webview_load)
        self.retries = 0
        self.max_retries = 10defon_webview_error(self, evt):
        self.URL = evt.GetURL()
        print(self.URL)
        self.retries += 1if self.retries > self.max_retries: # Give up
            self.Destroy()
        print("Error {} of {} attempts to load {}, trying again in 3 seconds.".format(self.retries,self.max_retries,self.URL))
        if self.retries > 5: # Try alternate
            self.URL = "http://wxPython.org"print("Swapping to alternate Url "+self.URL)
        self.browser.Destroy()

        time.sleep(3)

        self.browser = wx.html2.WebView.New(self, -1, size=(900,600))
        self.browser.Bind(wx.html2.EVT_WEBVIEW_ERROR, self.on_webview_error)
        self.browser.Bind(wx.html2.EVT_WEBVIEW_LOADED, self.on_webview_load)
        self.browser.LoadURL(self.URL)

    defon_webview_load(self, evt):
        print(self.URL, "Load complete")

if __name__ == '__main__':
  app = wx.App()
  dialog = MyBrowser(None, -1)
  dialog.browser.LoadURL(URL)
  dialog.Show()
  app.MainLoop()

Solution 2:

In wxPython you always have a main thread that is the one responsible for drawing and updating the GUI. In your MWE the line time.sleep(3) allows you to wait for 3 seconds before trying to reload the page again. However, this has the side effect of sending the main thread of the programm to sleep before being able to update the GUI and show the error message. If you move the time.sleep(3) line to a different thread the GUI may be updated without any problem. Here is a solution:

import wx 
import wx.html2 
import time
import _thread
from pubsub import pub

URL = "https://mydomain.tld"classMyBrowser(wx.Frame): 
    def__init__(self, *args, **kwds): 
        wx.Frame.__init__(self, *args, **kwds) 
        self.browser = wx.html2.WebView.New(self) 
        self.browser.Bind(wx.html2.EVT_WEBVIEW_ERROR, self.on_webview_error)
        self.counter = 0
        pub.subscribe(self.loadwww, 'Try Again')
        pub.subscribe(self.loadalt, 'Give UP')

    defloadwww(self):
        self.browser.LoadURL("https://mydomain.tld")

    defloadalt(self):
        self.browser.LoadURL("https://www.google.com")

    defon_webview_error(self, evt):
        self.counter += 1
        _thread.start_new_thread(self.wait, (3,))   

    defwait(self, sec):
        if self.counter <= 5:
            print(self.counter)
            print("Error: can't load page, try again in 3 seconds.")
            time.sleep(sec)
            wx.CallAfter(pub.sendMessage, 'Try Again')
        else:
            wx.CallAfter(pub.sendMessage, 'Give UP')    

if __name__ == '__main__': 
    app = wx.App() 
    dialog = MyBrowser(None, -1) 
    dialog.browser.LoadURL(URL) 
    dialog.Show() 
    app.MainLoop()