gjs/gnome-shell-extension: Updating button text every 60 seconds - gnome

Question

I want to write a simple gnome extension that prints some text on my top bar from a text file. I managed to print the text but i'm having trouble with updating it every 60 seconds. Is it even possible with gjs?
this is what i came up with:
const {St, Clutter} = imports.gi;
const Main = imports.ui.main;
const GLib = imports.gi.GLib;
let panelButton;
function init () {
// Create a Button with "Hello World" text
panelButton = new St.Bin({
style_class : "panel-button",
});
let fileContents = String(GLib.file_get_contents("path/to/myfile.txt")[1]);
let panelButtonText = new St.Label({
text : fileContents,
y_align: Clutter.ActorAlign.CENTER,
});
panelButton.set_child(panelButtonText);
}
function enable () {
// Add the button to the panel
Main.panel._centerBox.insert_child_at_index(panelButton, 2);
}
function disable () {
// Remove the added button from panel
Main.panel._centerBox.remove_child(panelButton);
}

Answer 1

You'll need to use GLib.timeout_add_seconds():
GLib.timeout_add_seconds(GLib.PRIORITY_DEFAULT, 60, () => {
updateLabel(newText);
return GLib.SOURCE_CONTINUE;
});
By the way, you should probably use ByteArray.toString() to convert the Uint8Array that you get from the file into a string.

Answer 2

If you want to have your extension approved by ego you'd possibly want to do it more like this (destroy in disable what you create in enable):
in extension.js:
let timeout = null;
in function enable():
timeout = GLib.timeout_add(GLib.PRIORITY_DEFAULT, (60 * 1000), () => {
// ...do the right thing...
return GLib.SOURCE_CONTINUE;
});
in function disable():
if (timeout) {
GLib.Source.remove(timeout);
timeout = null;
}