[LayoutRenderer("connectionstrings")]
    public class ConnectionStringsLayoutRenderer : LayoutRenderer
    {
        private static IConfigurationRoot _configurationRoot;

        internal IConfigurationRoot DefaultAppSettings
        {
            get => _configurationRoot;
            set => _configurationRoot = value;
        }

        /// <summary>
        /// Global configuration. Used if it has set
        /// </summary>
        public static IConfiguration AppSettings { private get; set; }

        ///<summary>
		/// The AppSetting name.
		///</summary>
		[RequiredParameter]
        [DefaultParameter]
        public string Name { get; set; }

        ///<summary>
        /// The default value to render if the AppSetting value is null.
        ///</summary>
        public string Default { get; set; }

        public ConnectionStringsLayoutRenderer()
        {

            if (AppSettings == null && DefaultAppSettings == null)
            {
                DefaultAppSettings = new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory())
                    .AddJsonFile("appsettings.json")
                    .AddJsonFile($"appsettings.{Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT")}.json", optional: true).Build();
            }
        }

        /// <summary>
        /// Renders the specified application setting or default value and appends it to the specified <see cref="StringBuilder" />.
        /// </summary>
        /// <param name="builder">The <see cref="StringBuilder"/> to append the rendered data to.</param>
        /// <param name="logEvent">Logging event.</param>
        protected override void Append(StringBuilder builder, LogEventInfo logEvent)
        {
            if (Name == null) return;

            string value = AppSettingValue;
            if (value == null && Default != null)
                value = Default;

            if (string.IsNullOrEmpty(value) == false)
                builder.Append(value);
        }

        private bool _cachedAppSettingValue = false;
        private string _appSettingValue = null;
        private string AppSettingValue
        {
            get
            {
                Name = Name.Replace('.', ':');
                if (_cachedAppSettingValue == false)
                {
                    _appSettingValue = AppSettings == null ? DefaultAppSettings.GetConnectionString(Name) : AppSettings[Name];
                    _cachedAppSettingValue = true;
                }
                return _appSettingValue;
            }
        }
    }