Transfer json from js to wasm

Here is a simple example about how to pass information by json from js to wasm (C++ generated).

We will pass enum value with json in the following project.

C++

enum class CType{
    T_A,
    T_B,
    None
};

void UModule::SetSlotType(std::string slotTypeJson)
{
    CType type = CType::None;
    nlohmann::json jsonObj = nlohmann::json::parse( slotTypeJson );
    if( jsonObj.contains("slotType") )
    {
        std::string str = jsonObj["slotType"];
        if( str == "T_A" )
        {
            type = CType::T_A;
        }
        else 
        {
            // ...
        }
    }

    LOG( INFO, "slotTypeJson: ", slotTypeJson, "\n, type: ", int( type ) );
}

JS:

const data = { slotType: "T_A" };  // T_A, T_B, None
const jsonStr = JSON.stringify(data);
moduleObj.SetSlotType( jsonStr )

If you want to write a whole CPlusPlus + js web app, you can refer to our old project: https://www.weiy.city/2021/12/export-cplusplus-algorithm-to-javascript-code/

nlohmann::json can be import from json.hpp, the project: https://github.com/nlohmann/json