tokensToFunction function

PathFunction tokensToFunction(List tokens, { bool sensitive = false, String encode(String)?, bool validate = true, })

Implementation

PathFunction tokensToFunction(
  List<Token> tokens, {
  bool sensitive = false,
  String Function(String)? encode,
  bool validate = true,
}) {
  final encoder = encode ?? _defaultEncode;

  // Compile all the tokens into regexps.
  final matches = tokens.map((token) {
    if (token is RegExp) {
      return RegExp('^(?:${token.pattern})\$', caseSensitive: false);
    }
  });

  return (dynamic data) {
    String path = '';

    for (int i = 0; i < tokens.length; i++) {
      final token = tokens[i];

      if (token is String) {
        path += token;
        continue;
      }

      final value = data != null ? data[token.name] : null;
      final optional = token.modifier == '?' || token.modifier == '*';
      final repeat = token.modifier == '*' || token.modifier == '+';

      if (value is List) {
        if (!repeat) {
          // 'Expected "${token.name}" to not repeat, but got an array'
          throw TypeError();
        }

        if (value.isEmpty) {
          if (optional) {
            continue;
          }

          // 'Expected "${token.name}" to not be empty'
          throw TypeError();
        }

        for (var j = 0; j < value.length; j++) {
          final segment = encoder.call(value[j] as String);

          if (validate && !(matches.elementAt(i) as RegExp).hasMatch(segment)) {
            // 'Expected all "${token.name}" to match "${token.pattern}", but got "${segment}"'
            throw TypeError();
          }

          path += '${token.prefix}$segment${token.suffix}';
        }

        continue;
      }

      if (value is String || value is num) {
        final segment = encoder.call(value.toString());

        if (validate && !(matches.elementAt(i) as RegExp).hasMatch(segment)) {
          // 'Expected "${token.name}" to match "${token.pattern}", but got "${segment}"'
          throw TypeError();
        }

        path += '${token.prefix}$segment${token.suffix}';
        continue;
      }

      if (optional) {
        continue;
      }

      // final typeOfMessage = repeat ? "an array" : "a string";
      // 'Expected "${token.name}" to be ${typeOfMessage}'
      throw TypeError();
    }

    return path;
  };
}