Wails: Quit app from within backend

[Pixdigit]

It could very well be that I missed it somewhere but is there a way to programmatically exit the application I mean besides OS.exit() which is unclean?

[leaanthony]

Hey @Pixdigit. Thanks for opening this. It's true, there isn't a specific runtime call to do this and I think it's a glaring omission. I consider this a bug and will add it this week :+1:

[leaanthony]

Technically, runtime.Window.Close() will exit from the app but there is no callback to allow you to shut down your resources, which is what I'm assuming you are wanting.

[leaanthony]

Hey there, I did a new release with a bunch of stuff around application shutdown. You can now hook into application shutdown using WailsShutdown. This will get called whenever you call runtime.Window.Close(), Kill the window or use ctrl-c (Windows is tricky on this front).

Example that I used for testing:

package main

import (
    "github.com/wailsapp/wails"
)

type Test struct {
    runtime *wails.Runtime
    log     *wails.CustomLogger
}

func NewTest() *Test {
    return &Test{}
}

func (t *Test) Kill() {
    t.runtime.Window.Close()
}

func (t *Test) WailsInit(runtime *wails.Runtime) error {
    t.runtime = runtime
    t.log = runtime.Log.New("Test Struct")
    return nil
}

func (t *Test) WailsShutdown() {
    t.log.Info("WailsShutdown() Called!")
}

Calling window.backend.Test.Kill() does exactly what you think it should.

Update using wails update and let me know how you get on.

[Pixdigit]

Yes, that is what I mean. However in my setup (with v0.18.5) WailsShutdown isn't called. Besides in the api reference you return an error but do not declare a return type. So must WailsShutdown return an error? This is the code code I used for the testing. I also tried without returning an error.

[leaanthony]

Hi. Where in the reference does it state you need to return an error? I searched codebase plus docs. Also, what OS are you using?

[leaanthony]

Running your test app I get:

$ ./shutdown 
Bound Runtime
Shutting Down!

Running in debug mode and shutting down via js command window.backend.Runtime.Quit:

$ ./shutdown
Fermion - Debug Build
---------------------
INFO[0000] [App] Starting                               
INFO[0000] [WebView] Initialised                        
INFO[0000] [Events] Starting                            
INFO[0000] [IPC] Starting                               
INFO[0000] [Bind] Starting                              
INFO[0000] [Bind] Binding Go Functions/Methods          
INFO[0000] [Bind] Bound Method: main.Runtime.Quit()     
Bound Runtime
INFO[0000] [Events] Listening                           
INFO[0000] [WebView] Running...                         
Goodbye!
Shutting Down!

[Pixdigit]

In line 19 you return nil even tough no return value is declared.

I use Ubuntu. Very weird that it does not invoke it on my system.

And for me the output (without returning an error in WailsShutdown) is:

Fermion - Debug Build
---------------------
INFO[0000] [App] Starting                               
INFO[0000] [WebView] Initialised                        
INFO[0000] [Events] Starting                            
INFO[0000] [Events] Listening                           
INFO[0000] [IPC] Starting                               
INFO[0000] [Bind] Starting                              
INFO[0000] [Bind] Binding Go Functions/Methods          
INFO[0000] [Bind] Bound Method: main.Runtime.Quit()     
INFO[0000] [Bind] Bound Method: main.Runtime.WailsShutdown() 
Bound Runtime
INFO[0000] [WebView] Running...                         
Goodbye!

[bh90210]

@Pixdigit I think the return nil it's probably a typo.

[leaanthony]

Thanks @Pixdigit. Will fix the docs!

[leaanthony]

Also, Please test against the latest pre release wails update -pre for the Shutdown issue.

[Pixdigit]

I made an empty test project with the code shared in pastebin. In that case everything works as intended.
Turns out I forgot to wails migrate. To mitigate this issue maybe execute wails migrate automatically after wails update since it modifies the project only with consent.

[leaanthony]

Ah that's great news. wails migrate is really new and I think I'd rather that be a manual process as it's a one-off operation. Really pleased it's working for you and thanks for opening this issue. It's something we really needed to address and the project as a whole is much better for it :+1: