interface.html: Controlling the current Bangle.js app

[ticalc-travis]

I've got together a working interface.html that provides an alternate way of editing the timer definitions in the app I'm working on. But I just discovered by accident that it's possible to click the Save Timers button in this interface while the timer app is currently running on the Bangle.js. The app doesn't know about the updated timers file just pushed to the device, so it retains the old data in memory and ends up overwriting the new data just pushed. Is there a way to ensure the app is not running when this happens, e.g. by forcing it to exit before sending the timers file, so that when it's loaded again it picks up the new data properly? The most obvious idea would be to send a load() call, but it seems I had trouble with that from interface.html before. But maybe it would okay if I did that, wait a moment, and then do the Util.writeStorage in a setTimeout call?

[gfwilliams]

You could use something like Puck.write("if (global.__FILE__=='myapp.app.js')load()\n", callback) and then delay a bit as you suggest to load out of your app if you were in it.

... or what about writing your updated timer file and then doing something like:

Puck.write("if (global.__FILE__=='myapp.app.js')reloadMyTimers()\n")`

Where reloadMyTimers() is a function in your app that'll cause it to reload the data that you just wrote?

[ticalc-travis]

Thanks! I think loading entirely out of the app is the simplest and safest way for now. But I'm sporadically getting a weird error in the console. This is the code I tried:

                // Ensure timer app is not running while we replace the timer file
                Puck.write("if (global.__FILE__=='" + APP_FILE + "')load();", () => {
                    setTimeout(() => {
                        Util.writeStorage(TIMERS_FILE, JSON.stringify(userTimers), () => {
                            alert('Timers saved successfully.');
                        });
                    }, 2000);
                });

The Bangle console looks like this:

>if (global.__FILE__=='tevtimer.app.js')load();g.drawRect(10,g.getHeight()-16,g.getWidth()-10,g.getHeight()-8).flip();p=x=>g.fillRect(10,g.getHeight()-16,10+(g.getWidth()-20)*x/100,g.getHeight()-8).flip();
=function (x) { ... }
saving timers
saving settings
>Uncaught ReferenceError: "p" is not defined
 at line 1 col 601
...YaKYiM7AALEQro")),0,1011);;p(100);Bluetooth.println("OK")

It appears the app exits, and the file appears to get sent successfully, but then this p(100) thing causes an error and the “Timers saved successfully” alert that I call from the writeStorage callback doesn't run. I tried moving the setTimeout out of the Puck.write callback and get the same result. The value of the timeout doesn't seem to help either; I tried a value of up to 5000. That only seemed to delay the app exit by 5 seconds, rather than the write to storage afterward…?

[gfwilliams]

I think it's because you're not writing a newline in the Puck.write call (see the code I posted above) so the code isn't executing immediately. I imagine it executes only when the next command is sent (for the file upload?) some time later - so you're getting all kinds of crazy errors when the Bangle reloads halfway through uploading the file?

[ticalc-travis]

Ah thanks, that seems really obvious now. Yeah, adding the newline seems to work properly.