V10 property update issue

[Matt Crawford]

With the recent V10 code base, I was testing the app update functionality and came across an issue that I can't resolve:

// the go-app version I used
github.com/maxence-charriere/go-app/v10 v10.0.0-20240312064243-fd8d583dcdfa

I was trying to develop a version component that allows click to check for new version and then click to reload the application if a new version is available. Here's the component ( it contains some additional logging of the pointer to *Version):

package compo

import (
	"fmt"
	"github.com/maxence-charriere/go-app/v10/pkg/app"
)

var _ app.AppUpdater = (*Version)(nil)
var _ app.Mounter = (*Version)(nil)

type Version struct {
	app.Compo
	UpdateAvailable string
}

func (v *Version) OnMount(ctx app.Context) {
	app.Log("OnMount", fmt.Sprintf("%v %q", &v, v.UpdateAvailable))
}

func (v *Version) OnAppUpdate(ctx app.Context) {
	app.Log("OnAppUpdate 1", fmt.Sprintf("%v %q", &v, v.UpdateAvailable))
	if ctx.AppUpdateAvailable() {
		v.UpdateAvailable = "yes"
		app.Log("OnAppUpdate 2", fmt.Sprintf("%v %q", &v, v.UpdateAvailable))
	}
}

func (v *Version) Render() app.UI {
	app.Log("Render", fmt.Sprintf("%v %q", &v, v.UpdateAvailable))
	if v.UpdateAvailable == "yes" {
		return app.Div().Class("version").Text("Update Available").
			OnClick(func(ctx app.Context, e app.Event) {
				ctx.Reload()
			})
	}
	return app.Div().Class("version").Text(app.Getenv("GOAPP_VERSION")).
		OnClick(func(ctx app.Context, e app.Event) {
			ctx.Dispatch(func(context app.Context) {
				context.TryUpdateApp()
			})
		})
}

The root object and route are as follows:

func (r *Root) Render() app.UI {
	return app.Div().Body(&Version{})
}

app.Route("/", func() app.Composer { return &Root{} })

The log indicates the pointer to *Version changes in between the OnAppUpdate() and Render() calls so the if condition in the Render() does not find the proper value for v.AppUpdateAvailable

The console log:

At 19:49:39 is when the version component is first clicked.

The full code is located here:
https://github.com/mlctrez/mlctrez.github.io/tree/v0.0.7/goapp/compo

[Hans Raaf]

Try "c.updateAvailable" instead of "c.UpdateAvailable"

[Maxence Charriere]

Don’t export the UpdateAvailable field.

[Matt Crawford]

My bad. I could have sworn I knew that rule and already tried making it lowercase to see if that worked. Closing.