Indicator-as-parameter-in-GenerateParameters-for-custom-library

Here is the correct syntax.

There are a few things to note,

1) Add the assignments to IndicatorAbbreviation, IndicatorParameters, and IndicatorInstance in the constructor.
2) Use the helper method AddIndicatorParameter in the GenerateParameters.
3) In Populate, extract the IndicatorAbbreviation and IndicatorParameters, then call IndicatorFactory.Instance.CreateIndicator to create the indicator's instance.

CODE:

using WealthLab.Core;
using WealthLab.Indicators;
using System;

namespace WealthLabCustom
{
   public class Weighting : IndicatorBase
   {
      public Weighting() : base()
      {
         LibraryName = "RiMarBo";
      }

      //for code based construction
      public Weighting(BarHistory barHistory, IndicatorBase indicatorSource1, double weightSource1,
                   IndicatorBase indicatorSource2, int lookbackPctRank) : base()
      {
         LibraryName = "RiMarBo";
         Parameters[0].Value = barHistory;
         Parameters[1].Value = indicatorSource1;
         Parameters[1].IndicatorInstance = indicatorSource1;
         Parameters[1].IndicatorAbbreviation = indicatorSource1.Abbreviation;
         Parameters[1].IndicatorParameters = indicatorSource1.Parameters;
         Parameters[2].Value = weightSource1;
         Parameters[3].Value = indicatorSource2;
         Parameters[3].IndicatorInstance = indicatorSource2;
         Parameters[3].IndicatorAbbreviation = indicatorSource2.Abbreviation;
         Parameters[3].IndicatorParameters = indicatorSource2.Parameters;
         Parameters[4].Value = lookbackPctRank;
         Populate();
      }

      //abbreviation - Abkürzung im Suchbaum
      public override string Abbreviation => "Weighting";

      //description
      public override string HelpDescription => "Mix 2 indicators with an individual weighting factor. Each indicator is scaled from 0-100% before by 'PctRank'";

      //price pane
      public override string PaneTag => "WGHT";

      //name - Name im Pane wo Indikator beschrieben ist
      public override string Name => "Weighting Indicators";

      //default color
      public override WLColor DefaultColor => WLColor.Brown;

      //default plot style
      public override PlotStyle DefaultPlotStyle => PlotStyle.Line;


      //generate parameters
      protected override void GenerateParameters()
      {
         AddParameter("Source", ParameterType.BarHistory, null);
         AddIndicatorParameter("IndicatorSource1");
         AddParameter("WeightSource1", ParameterType.Double, 0.5);
         AddIndicatorParameter("IndicatorSource2");
         AddParameter("LookbackPctRank", ParameterType.Int32, 90);
      }

      //populate
      public override void Populate()
      {
         BarHistory source = Parameters[0].AsBarHistory;
         
         string indName = Parameters[1].IndicatorAbbreviation;
         ParameterList indParams = Parameters[1].IndicatorParameters;
         IndicatorBase ind1 = IndicatorFactory.Instance.CreateIndicator(indName, indParams, source);
         
         double weightSource1 = Parameters[2].AsDouble;
         
         indName = Parameters[3].IndicatorAbbreviation;
         indParams = Parameters[3].IndicatorParameters;
         IndicatorBase ind2 = IndicatorFactory.Instance.CreateIndicator(indName, indParams, source);
         
         double weightSource2 = 1 - weightSource1;
         Int32 lookbackPctRank = Parameters[4].AsInt;
         DateTimes = source.DateTimes;

         //calculate prct rank
         TimeSeries prctRankIndicator1 = new PctRank(ind1, lookbackPctRank);
         TimeSeries prctRankIndicator2 = new PctRank(ind2, lookbackPctRank);

         //calculate combined weight
         for (int idx = lookbackPctRank; idx < source.Count; idx++)
         {
            Values[idx] = weightSource1 * prctRankIndicator1[idx] + weightSource2 * prctRankIndicator2[idx];
         }
      }
   }
}