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Introduction

The runtime is a library that provides utility methods for your application. There is both a Go and JavaScript runtime and the aim is to try and keep them at parity where possible.

It has utility methods for:

The Go Runtime is available through importing github.com/wailsapp/wails/v2/pkg/runtime. All methods in this package take a context as the first parameter. This context should be obtained from the OnStartup or OnDomReady hooks.

Note

Whilst the context will be provided to the OnStartup method, there's no guarantee the runtime will work in this method as the window is initialising in a different thread. If you wish to call runtime methods at startup, use OnDomReady.

The JavaScript library is available to the frontend via the window.runtime map. There is a runtime package generated when using dev mode that provides TypeScript declarations for the runtime. This should be located in the wailsjs directory in your frontend directory.

Hide​

Go: Hide(ctx context.Context)
JS: Hide()

Hides the application.

Note

On Mac, this will hide the application in the same way as the Hide menu item in standard Mac applications. This is different to hiding the window, but the application still being in the foreground. For Windows and Linux, this is currently the same as WindowHide.

Show​

Shows the application.

Note

On Mac, this will bring the application back into the foreground. For Windows and Linux, this is currently the same as WindowShow.

Go: Show(ctx context.Context)
JS: Show()

Quit​

Quits the application.

Go: Quit(ctx context.Context)
JS: Quit()

Environment​

Returns details of the current environment.

Go: Environment(ctx context.Context) EnvironmentInfo
JS: Environment(): Promise<EnvironmentInfo>

EnvironmentInfo​

Go:

type EnvironmentInfo struct {
	BuildType string
	Platform  string
	Arch      string
}

JS:

interface EnvironmentInfo {
  buildType: string;
  platform: string;
  arch: string;
}

ResetSignalHandlers​

Resets signal handlers to allow panic recovery from nil pointer dereferences and other memory access violations.

Go: ResetSignalHandlers()

Linux Only

This function only has an effect on Linux. On macOS and Windows, it is a no-op.

On Linux, WebKit (used for the webview) may install signal handlers without the SA_ONSTACK flag, which prevents Go from properly recovering from panics caused by nil pointer dereferences (SIGSEGV) or other memory access violations.

Call this function immediately before code that might panic to ensure the signal handlers are properly configured for Go's panic recovery mechanism.

Example​

go func() {
    defer func() {
        if err := recover(); err != nil {
            log.Printf("Recovered from panic: %v", err)
        }
    }()
    // Reset signal handlers right before potentially dangerous code
    runtime.ResetSignalHandlers()

    // Code that might cause a nil pointer dereference...
    var t *time.Time
    fmt.Println(t.Unix()) // This would normally crash on Linux
}()
warning

This function must be called in each goroutine where you want panic recovery to work, and should be called immediately before the code that might panic, as WebKit may reset the signal handlers at any time.