assertParam method

void assertParam(
  1. String param, {
  2. bool? isOptional,
})

Throws ApiError if param does not exist as route parameter in this pattern.

If isOptional is non-null, it is also asserted, that the route parameter is optional or not.

Implementation

void assertParam(String param, {bool? isOptional}) {
  if (!containsParam(param) || (isOptional != isOptionalParam(param))) {
    final buffer = StringBuffer('RoutePattern requires ');
    if (isOptional != null) {
      if (!isOptional) {
        buffer.write('non-');
      }
      buffer.write('optional');
    }
    buffer.write(' parameter "$param".');
    throw ApiError(buffer.toString());
  }
}