apple2js/js/prefs.ts

const havePrefs = typeof window.localStorage !== 'undefined';

export default class Prefs {

    havePrefs() {
        return havePrefs;
    }

    readPref(name: string): string | null
    readPref(name: string, defaultValue: string): string
    readPref(name: string, defaultValue: string | null = null) {
        if (havePrefs) {
            return window.localStorage.getItem(name) ?? defaultValue;
        }
        return defaultValue;
    }

    writePref(name: string, value: string) {
        if (havePrefs) {
            window.localStorage.setItem(name, value);
        }
    }
}