json_schema.h

Go to the documentation of this file.

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the Apache 2.0 License.
#pragma once
 
#include <nlohmann/json.hpp>
#include <optional>
#include <string>
#include <valijson/adapters/nlohmann_json_adapter.hpp>
#include <valijson/schema.hpp>
#include <valijson/schema_parser.hpp>
#include <valijson/utils/nlohmann_json_utils.hpp>
#include <valijson/validator.hpp>
 
namespace json
{
  static std::optional<std::string> validate_json(
    const nlohmann::json& input_json, const nlohmann::json& schema_json)
  {
    valijson::Schema schema;
    valijson::SchemaParser parser;
    valijson::Validator validator;
 
    valijson::adapters::NlohmannJsonAdapter schema_adapter(schema_json);
    valijson::adapters::NlohmannJsonAdapter target_adapter(input_json);
 
    parser.populateSchema(schema_adapter, schema);
 
    valijson::ValidationResults results;
    if (!validator.validate(schema, target_adapter, &results))
    {
      std::string validation_error_msg;
      valijson::ValidationResults::Error error;
      size_t error_num = 0;
      while (results.popError(error))
      {
        std::string error_ctx;
        for (auto const& c : error.context)
        {
          error_ctx += c;
        }
        validation_error_msg += fmt::format(
          "\nError #{}:\n  context: {}\n  message: {}",
          error_num,
          error_ctx,
          error.description);
        ++error_num;
      }
      return validation_error_msg;
    }
 
    return std::nullopt;
  }
}