schema_validation_example.cpp

Demonstrates container schema validation with constraints.

Demonstrates container schema validation with constraints.Shows defining required/optional fields with types, range/length validators, and validating containers against schemas.

See also

kcenon::container::container_schema

// BSD 3-Clause License
// Copyright (c) 2021-2025, 🍀☀🌕🌥 🌊
// See the LICENSE file in the project root for full license information.
 
 
#include "container.h"
 
#include <kcenon/container/container/schema.h>
 
#include <iostream>
#include <string>
 
using namespace kcenon::container;
 
int main()
{
    std::cout << "=== Schema Validation Example ===" << std::endl;
 
    // 1. Define a schema with typed fields
    std::cout << "\n1. Defining schema:" << std::endl;
    auto schema = container_schema()
        .require("username", value_types::string_value)
        .require("age", value_types::int_value)
        .range("age", 0, 150)
        .length("username", 3, 20)
        .optional("nickname", value_types::string_value);
 
    std::cout << "   Fields: " << schema.field_count() << std::endl;
    std::cout << "   'username' required: " << (schema.is_required("username") ? "yes" : "no")
              << std::endl;
    std::cout << "   'nickname' required: " << (schema.is_required("nickname") ? "yes" : "no")
              << std::endl;
 
    // 2. Validate a valid container
    std::cout << "\n2. Validating valid container:" << std::endl;
    value_container valid;
    valid.set("username", std::string("alice"));
    valid.set("age", static_cast<int64_t>(25));
 
    auto result = schema.validate(valid);
    std::cout << "   Valid: " << (result ? "yes" : "no") << std::endl;
 
    // 3. Validate an invalid container (missing required field)
    std::cout << "\n3. Validating invalid container (missing age):" << std::endl;
    value_container invalid;
    invalid.set("username", std::string("bob"));
 
    auto errors = schema.validate_all(invalid);
    std::cout << "   Errors: " << errors.size() << std::endl;
    for (const auto& err : errors)
    {
        std::cout << "   - " << err.field << ": " << err.message << std::endl;
    }
 
    // 4. Schema inspection
    std::cout << "\n4. Schema inspection:" << std::endl;
    std::cout << "   Has 'username': " << (schema.has_field("username") ? "yes" : "no")
              << std::endl;
    std::cout << "   Has 'address': " << (schema.has_field("address") ? "yes" : "no")
              << std::endl;
 
    std::cout << "\nDone." << std::endl;
    return 0;
}