CODEWITHSUNDEEP
pythontkinter
daiyue
daiyue

Reputation: 7448

Tkinter event binding of entry widget for password verification

I am trying to use a entry widget for password input, a handler function for password verification and a label widget for displaying the result of the verification. The code is as following so far,

class LoginFrame(Frame):
    def __init__(self, parent):
        #Frame.__init__(self, parent)
        super(LoginFrame, self).__init__()

        self.parent = parent        
        self.initUI()

    # initialize the login screen UI  
    def initUI(self):
        # Set up login frame properties 
        self.parent.title("Login Screen")

        # creating instruction label
        inst_lbl = self.make_label(self.parent, "Please login to continue")

        # creating labels and entries for user name and password
        user_name = self.make_entry(self.parent, caption="User Name:")
        pwd = self.make_entry(self.parent, caption="User Password:", show="*")

        # create a login button
        login_btn = self.make_button(self.parent, self.verify_user, "Login")        


    # create a button 
    #----------------------------------------------------------------------
    def make_button(self, parent, command, caption=NONE, side=TOP, width=0, **options):
    """make a button"""
        btn = Button(parent, text=caption, command=command)

        if side is not TOP:
           btn.pack(side=side)
        else:
           btn.pack()    

        return btn


   def make_label(self, parent, caption=NONE, side=TOP, **options):
       label = Label(parent, text=caption, **options)

       if side is not TOP:
           label.pack(side=side)
       else:
           label.pack()

       return label


   def make_entry(self, parent, caption=NONE, side=TOP, width=0, **options):
       #Label(parent, text=caption).pack(side=LEFT)
       self.make_label(self.parent, caption, side)
       entry = Entry(parent, **options)
       if width:
          entry.config(width=width)
       if side is not TOP:
          entry.pack(side=side)
       else:
          entry.pack()

       return entry        


   # verify user name and password
   #----------------------------------------------------------------------
   def verify_user(event):
       """verify users"""
       if user_name.get() == "admin" and pwd.get() == "123":
           #inst_lbl.configure(text="User verified")
           event.widget.config(text="User verified")
       else:
           #inst_lbl.configure(text="Access denied. Invalid username or password")
           event.widget.config(text="Access denied. Invalid username or password")


def main():
    top = Tk()    
    app = LoginFrame(top)
    top.mainloop()


if __name__ == '__main__':
    main()

now, I need user_name and pwd to be verified by the method verify_user, the result is shown in inst_lbl whenever the button login_btn is clicked (to trigger the verification). So how to bind inst_lbl to verify_user, in response to the login_btn click event? and how to get the contents of user_name and pwd to get verified in verify_user?

Upvotes: 0

Views: 197

Answers (1)

Lafexlos
Lafexlos

Reputation: 7735

Make them class variable by adding self. prefixes. This way you can access them outside of the method they are created. 

self.inst_lbl = self.make_label(...)
self.user_name = self.make_entry(...)
self.pwd = self.make_entry(...)

When trying to call them, you also will need self. prefixes.

self.inst_lbl.configure(...)

Other than that, you'll be needing self parameter in verify_user method since it's a member of a class.

Also, for Python-2.x, you'll get TypeError: must be type, not classobj on your super(LoginFrame, self).__init__(). The line you commented out is the right one to use.

Frame.__init__(self, parent)

If you want to use super(), you should add object as parameter to your class definiton because of old style classes etc.

class LoginFrame(Frame, object):

Upvotes: 1

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