Information_only properties don't work for custom representation

Development
1

Dear Paraview developers,
I have a custom representation, which is a subclass of vtkXYChartRepresentation. It has a property and I want to manipulate its visibility depending on the input. I have created an information_only property to manage that. The xml configuration looks something like that:

<ChartRepresentationProxy base_proxygroup="representations"
						  base_proxyname="XYChartRepresentation"
						  class="vtkXYMyChartRepresentation"
                          name="XYMyChartRepresentation"
                          processes="client|dataserver|renderserver"
                          post_creation="SetChartTypeToLine">		

	<IntVectorProperty name="VisualizationType"
                       command="GetVisualizationType"
                       information_only="1"/>

	<DoubleVectorProperty command="SetMyProperty"
							default_values="0"
							name="MyProperty"
							number_of_elements="1">
		<DoubleRangeDomain max="1"
						   min="0"
						   name="range" />
	</DoubleVectorProperty>
	
</ChartRepresentationProxy>

Then I manipulate the VisualizationType in RequestData

int vtkXYMyChartRepresentation::RequestData(
  vtkInformation* request, vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  if (!this->Superclass::RequestData(request, inputVector, outputVector))
    return 0;
 
  VisualizationType = 1;
  this->PlotDataHasChanged = true;
  return 1;
}

However, the visibility of MyProperty doesn’t change depending on what value I set in RequestData, it is visible if I contruct it like VisualizationType{1} and invisible if VisualizationType{0}. The function GetVisualizationType() doesn’t seem to get called at all. What am I doing wrong and what are the ways to implement that kind of behaviour?

2
  1. You are changing the value of the VisualizationType ivar without marking the filter as modified; thus the ParaView client/server framework does not know it has changed on the server.
  2. You should not always mark a filter as modified in RequestData() since that will require the filter to re-execute immediately (i.e., it will never terminate).

There may be other issues, but those jumped out at me.