Demo: JSON Utilities

Demonstrates JSON booleans, object merging, array appending, serialization, and field extraction.

1. Example Scope

The page mirrors the repository source, CMake target, and current API, with English comments for the relevant calls.

2. Build and Run

cmake --build build --target sttnet_json_tools --parallel
./build/examples/sttnet_json_tools

3. Validation

./build/examples/sttnet_json_tools

Expected: Prints a serialized object, the name field, a small object with a real boolean, a merged object, an appended array, and the roles field.

4. Complete Source

#include <sttnet.h>

#include <iostream>

int main()
{
    using stt::data::JsonHelper;

    // Json::Value is the clearest option for nested data.
    Json::Value user(Json::objectValue);
    user["id"]=1001;
    user["name"]="Stephen";
    user["online"]=true;
    user["roles"].append("developer");
    user["roles"].append("operator");

    const std::string jsonText=JsonHelper::toString(user);
    std::cout << "serialized: " << jsonText << '\n';

    const Json::Value parsed=JsonHelper::toJsonArray(jsonText);
    if(!parsed.isObject())
        return 1;
    std::cout << "name: " << parsed["name"].asString() << '\n';

    // createJson() preserves booleans as JSON true/false rather than integers.
    const std::string small=JsonHelper::createJson("status","ok","online",true,"count",3);
    std::cout << "small object: " << small << '\n';

    // jsonAdd() merges object members or appends array elements. Mixing an object
    // and an array is invalid and returns an empty string.
    std::cout << "merged object: "
              << JsonHelper::jsonAdd("{\"a\":1}","{\"b\":2}") << '\n';
    std::cout << "appended array: "
              << JsonHelper::jsonAdd("[1]","[2,3]") << '\n';

    std::string extracted;
    const int type=JsonHelper::getValue(jsonText,extracted,"value","roles");
    std::cout << "roles type=" << type << ", value=" << extracted << '\n';
    return 0;
}