combine static method

String? Function(String?) combine(List<InputValidation> validations)

组合多个校验规则 / Combine multiple validation rules

按顺序执行所有校验，返回第一个错误 Execute all validations in order, return the first error

Example:

validator: InputValidation.combine([
  const InputValidation(mustFill: true, emptyTip: "不能为空"),
  InputValidation.minLength(6, errorMsg: "至少6个字符"),
  InputValidation.email(errorMsg: "邮箱格式不正确"),
])

Implementation

static String? Function(String?) combine(List<InputValidation> validations) {
  return (String? value) {
    for (var validation in validations) {
      final error = validation.validate(value);
      if (error != null) {
        return error;
      }
    }
    return null;
  };
}