parseBool function
Parse simple boolean ("on"/"off", "1"/"0", "yes"/"no"). Roadmap #153.
Implementation
bool? parseBool(String input) {
final String s = input.trim().toLowerCase();
const Set<String> trueValues = <String>{'true', '1', 'yes', 'on'};
const Set<String> falseValues = <String>{'false', '0', 'no', 'off'};
if (trueValues.contains(s)) return true;
if (falseValues.contains(s)) return false;
return null;
}