Formatters that only run when the triggering value changes

Today, we have these great formatters to display values/string in a different way. However, these formatters seems to constantly (re)run even if the base value/string has not changed.

For example, if you create a custom formatter that simply console logs and returns you can see if just keeps running.

dmx.Formatter('string', 'tester', function (str) {
    console.log('formatter run');
    return str;
});

No big deal until there are dozens/hundreds of more complicated formatters running on a page.

Is it possible for the formatter to only run once when it is initialized and not run again until the dynamic data using the formatter changes, or is updated?