gistfile1.txt

void SparkVariable::callFinished(QJsonDocument json) {
    if (json.isNull()) goto cleanup;
    if (! json.isObject()) { qDebug() << "expected a json object"; goto cleanup; }
    QJsonObject jo = json.object();
    if (jo.isEmpty()) { qDebug() << "json object is empty"; goto cleanup; }

    QJsonValue return_value = jo["return_value "];
    QVariant value = return_value.toVariant();

    qDebug() << "a function from " << m_variable << " returned " << return_value;

    emit result(value);
cleanup:
    emit busyChanged(m_busy=false);
    return;
}

// Using lambdas : 

void SparkVariable::callFinished(QJsonDocument json) {
    auto cleanup = [this] () {
        emit busyChanged(m_busy = false);
    };

    if (json.isNull()) { cleanup(); return; }
    if (! json.isObject()) { qDebug() << "expected a json object"; cleanup(); return; }
    QJsonObject jo = json.object();
    if (jo.isEmpty()) { qDebug() << "json object is empty"; cleanup(); return; }

    QJsonValue return_value = jo["return_value "];
    QVariant value = return_value.toVariant();

    qDebug() << "a function from " << m_variable << " returned " << return_value;

    emit result(value);
    cleanup();
}