toNullableBoolean static method
Converts value into boolean or returns null when conversion is not possible.
value
the value to convert. Returns boolean value or null when convertion is not supported.
Implementation
static bool? toNullableBoolean(value) {
if (value == null) return null;
if (value is bool) return value;
if (value is num) return value != 0;
value = value.toString().toLowerCase();
if (value == '1' ||
value == 'true' ||
value == 't' ||
value == 'yes' ||
value == 'y') return true;
if (value == '0' ||
value == 'false' ||
value == 'f' ||
value == 'no' ||
value == 'n') return false;
return null;
}