Refresh a tkinter frame on button press

Question

I am utilising code from Switch between two frames in tkinter to make my GUI. I have a frame with refresh and restart buttons.

My original idea was for the restart

Answer 1

The first step is to have your button call a proper function rather than using lambda. Unless you understand why and when to use lambda, it usually just makes the code harder to write and understand.

Once you have it call a function, you can use the function to clear the entries.

Example:

class PLG(tk.Frame):
    def __init__(self, parent, controller):
        ...
        tk.Button(self, text="Restart", command=self.restart)
        tk.Button(self, text="Refresh", command=self.refresh)
        ...

    def restart(self):
        self.refresh()
        self.controller.show_frame("StartPage")

    def refresh(self):
        self.weight_entry.delete(0, "end")
        self.text.delete("1.0", "end")

Answer 2

The OP's question was about clearing input fields so prior input isn't still in the page when you expected to see empty fields for fresh input. I'm posting the finished code while omitting features of the OP's original code which were irrelevant to his question so the solution could easily be seen in its full context. I had been looking to solve this problem with this same frame-switching code from Bryan Oakley's famed tutorials on this topic. I also included an alternate version using grid_remove instead of tkraise since this is how I had solved the problem of ever-active but unseen frames trying to participate in the focus traversal as the user tries to tab through the page. It also kept the frames from all trying to be the same size.

import tkinter as tk

class SampleApp(tk.Tk):

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)

        container = tk.Frame(self)
        container.pack(side="top", fill="both", expand=True)
        container.grid_rowconfigure(0, weight=1)
        container.grid_columnconfigure(0, weight=1)

        self.frames = {}

        # alternate ways to create the frames & append to frames dict: comment out one or the other

        for F in (StartPage, PLG):
            page_name = F.__name__
            frame = F(parent=container, controller=self)
            self.frames[page_name] = frame
            frame.grid(row=0, column=0, sticky="nsew")

        # self.frames["StartPage"] = StartPage(parent=container, controller=self) 
        # self.frames["PLG"] = PLG(parent=container, controller=self)
        # self.frames["StartPage"].grid(row=0, column=0, sticky="nsew")
        # self.frames["PLG"].grid(row=0, column=0, sticky="nsew")

        self.show_frame("StartPage")

    # alternate version of show_frame: comment out one or the other

    def show_frame(self, page_name):
        for frame in self.frames.values():
            frame.grid_remove()
        frame = self.frames[page_name]
        frame.grid()

    # def show_frame(self, page_name):
        # frame = self.frames[page_name]
        # frame.tkraise()

class StartPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller

        label = tk.Label(self, text="start page")
        label.pack(side="top", fill="x", pady=10)

        button1 = tk.Button(self, text="Go to Page One", command=lambda: controller.show_frame("PLG"))
        button1.pack()        

        button2 = tk.Button(self, text="focus traversal demo only")
        button2.pack()
        button2.focus_set()

        button3 = tk.Button(self, text="another dummy button")
        button3.pack()

        lbl = tk.Label(self, text="tkraise messes up focus traversal\nwhich you can see by testing the two versions of show_frame.()\nUsing grid_remove instead of tkraise solves that,\nwhile preventing frames from being unable to resize to fit their own contents.")
        lbl.pack()

class PLG(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        label = tk.Label(self, text="Enter something below; the two buttons clear what you type.")
        label.pack(side="top", fill="x", pady=10)
        self.wentry = tk.Entry(self)
        self.wentry.pack(pady = 10)
        self.text = tk.Text(self)
        self.text.pack(pady = 10)
        restart_button = tk.Button(self, text="Restart", command=self.restart)
        restart_button.pack()
        refresh_button = tk.Button(self, text="Refresh", command=self.refresh) 
        refresh_button.pack()  

    def restart(self):
        self.refresh()
        self.controller.show_frame("StartPage")

    def refresh(self):
        self.wentry.delete(0, "end")
        self.text.delete("1.0", "end")
        # set focus to any widget except a Text widget so focus doesn't get stuck in a Text widget when page hides
        self.wentry.focus_set()

if __name__ == "__main__":
    app = SampleApp()
    app.mainloop()

Answer 3

Simple way: Just call that window with button or bind in which frame lies.

works good for windows refresh.