PublishingConfigAttributes.cpp

This example demonstrates how to publish configuration attributes of a skill element.

#include <xentara/config/Context.hpp>
#include <xentara/config/Errors.hpp>
#include <xentara/data/ReadHandle.hpp>
#include <xentara/model/Attribute.hpp>
#include <xentara/model/ElementCategory.hpp>
#include <xentara/model/ForEachAttributeFunction.hpp>
#include <xentara/skill/Element.hpp>
 
#include <xentara/utils/core/Uuid.hpp>
#include <xentara/utils/json/decoder/Errors.hpp>
#include <xentara/utils/json/decoder/Object.hpp>
 
#include <memory>
#include <string_view>
#include <optional>
 
//#############################################
// Declaration of MyElement class
//#############################################
 
using namespace std::literals;
using namespace xentara::literals;
 
// This class represents a MyElement
class MyElement final : public xentara::skill::Element, public xentara::skill::EnableSharedFromThis<MyElement>
{
public:
    // This type contains the meta information for the element type
    using Class = xentara::skill::Element::ConcreteClass<"MyElement", "759ce2f0-6ae9-40ea-8c0b-8f19eac38359"_uuid, "my element">;
 
    auto category() const noexcept -> model::ElementCategory final
    {
        return model::ElementCategory::SpecialPurpose;
    }
 
    // These are the objects that identify the attributes
    static const xentara::model::Attribute kFactorAttribute;
    static const xentara::model::Attribute kOffsetAttribute;
 
protected:
    auto load(xentara::utils::json::decoder::Object &jsonObject, xentara::config::Context &context) -> void override;
 
    auto forEachAttribute(const model::ForEachAttributeFunction &function) const -> bool final;
 
    auto makeReadHandle(const model::Attribute &attribute) const noexcept -> std::optional<data::ReadHandle> final;
 
private:
    // These are some configuration parameters
    double factor { 1.0 };
    double offset { 0.0 };
};
 
//#############################################
// Implementation of MyElement class
//#############################################
 
using namespace std::literals;
 
const xentara::model::Attribute MyElement::kFactorAttribute{ "cb94c929-1e9e-4153-80c8-82b48a2abd73"_uuid, "factor"sv, xentara::model::Attribute::Access::ReadOnly, xentara::data::DataType::kFloatingPoint };
const xentara::model::Attribute MyElement::kOffsetAttribute{ "0a648093-7293-42f4-8f25-b0d315c8622a"_uuid, "offset"sv, xentara::model::Attribute::Access::ReadOnly, xentara::data::DataType::kFloatingPoint };
 
auto MyElement::load(xentara::utils::json::decoder::Object &jsonObject, xentara::config::Context &context) -> void
{
    // Loop through all the members of the JSON object
    for (auto && [name, value] : jsonObject)
    {
        // Check the different keys
        if (name == "factor"sv)
        {
            _factor = value.toNumber<double>();
        }
        else if (name == "offset"sv)
        {
            _offset = value.asNumber<double>();
        }
        else
        {
            // Throw an error for unknown parameters
            xentara::config::throwUnknownParameterError(name);
        }
    }
}
 
auto MyElement::forEachAttribute(const model::ForEachAttributeFunction &function) const -> bool
{
    return
        function(kFactorAttribute) ||
        function(kOffsetAttribute);
}
 
auto MyElement::makeReadHandle(const model::Attribute &attribute) const noexcept -> std::optional<data::ReadHandle>
{
    if (attribute == kFactorAttribute)
    {
        return sharedFromThis(&_factor);
    }
    if (attribute == kOffsetAttribute)
    {
        return sharedFromThis(&_offset);
    }
}