parseBool static method

bool? parseBool(Object? value, [ bool? def ])

Tries to parse a bool.

• Returns def if value is invalid.

Implementation

static bool? parseBool(Object? value, [bool? def]) {
  if (value == null) return def;

  if (value is bool) {
    return value;
  } else if (value is num) {
    return value > 0;
  } else {
    var s = _valueAsString(value).toLowerCase();

    if (s.isEmpty ||
        s == 'null' ||
        s == 'empty' ||
        s == '[]' ||
        s == 'undef' ||
        s == 'undefined') {
      return def;
    }

    if (s == 'true' ||
        s == 't' ||
        s == 'yes' ||
        s == 'y' ||
        s == 's' ||
        s == '1' ||
        s == '+' ||
        s == 'ok' ||
        s == 'on' ||
        s == 'enabled' ||
        s == 'selected' ||
        s == 'checked' ||
        s == 'positive') {
      return true;
    }

    if (s == 'false' ||
        s == 'f' ||
        s == 'no' ||
        s == 'n' ||
        s == '0' ||
        s == '-1' ||
        s == '-' ||
        s == 'fail' ||
        s == 'error' ||
        s == 'err' ||
        s == 'off' ||
        s == 'disabled' ||
        s == 'unselected' ||
        s == 'unchecked' ||
        s == 'negative') {
      return false;
    }

    var n = _parseNumString(value);
    if (n != null) {
      return n > 0;
    }

    return def;
  }
}