empty default input parameters on custom component

Hello,
I would like one of my input parameters to be optional, with nothing as a default but a brep list if connected. I see that I can specify a default value for string parameters like "test" below. Is their something similiar for geometry. When the component is compiled I get a runtime warning "failed to collect data" unless I attach a Brep.

Protected Overrides Sub RegisterInputParams(ByVal pManager As Grasshopper.Kernel.GH_Component.GH_InputParamManager)

pManager.Register_StringParam("Variant Name", "Variant", "Variant name, "test", GH_ParamAccess.item)
pManager.Register_BRepParam("Geometry 2", "Geo2", "List of Breps", GH_ParamAccess.list)

Replies to This Discussion

Permalink Reply by Damien Alomar on September 21, 2010 at 11:38am

After you've registered the parameter you can then change things about it by accessing it directly through the pManager. Something like this will work....



pManager.Register_StringParam("Variant Name", "Variant", "Variant name, "test", GH_ParamAccess.item)

pManager.Register_BRepParam("Geometry 2", "Geo2", "List of Breps", GH_ParamAccess.list)



'the Brep param is index 1

pManager(1).Optional = True

Permalink Reply by Jeff Niemasz on September 21, 2010 at 1:56pm

Thanks Damien, works perfectly.

Permalink Reply by David Rutten on May 7, 2013 at 7:12am

Register_XXXXParam methods have been replaced by AddXXXXParameter in some recent version.

Making parameters optional is done with:

pManager(2).Optional = True

in case the third input has to be optional.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by David Rutten on May 7, 2013 at 9:12am

You do this in RegisterInputParams() right?

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by David Rutten on May 7, 2013 at 10:04am

That is very strange. Which exact error do you get:

Parameter failed to collect data
Input parameter <nickname> failed to collect data
Floating parameter <nickname> failed to collect data
Parameter <nickname> of unknown type failed to collect data

Can you post a screenshot of the component with the error and your RegisterInputParams code?

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by David Rutten on May 8, 2013 at 5:22am

Sorry Hans but I simply cannot repeat that.

I pasted your code into a blank component and it works as expected:

Public Class testcomponent
Inherits GH_Component
Public Sub New()
MyBase.New("Bla", "Blah", "yada yada", "cat", "sub")
End Sub
Public Overrides ReadOnly Property ComponentGuid As System.Guid
Get
Return Guid.NewGuid
End Get
End Property
Protected Overrides Sub RegisterInputParams(pManager As Kernel.GH_Component.GH_InputParamManager)
pManager.AddBooleanParameter("Boolean", "B", "Turn the component on or off", GH_ParamAccess.item)
pManager.AddTextParameter("String", "N", "New Parameters", GH_ParamAccess.item)
pManager.AddTextParameter("String", "I", "Input file path", GH_ParamAccess.item)
pManager.AddTextParameter("String", "L", "Local copy path", GH_ParamAccess.item)
pManager.AddTextParameter("String", "U", "User Name", GH_ParamAccess.item)
pManager(2).Optional = True 'this doesn't work
pManager(3).Optional = True
End Sub
Protected Overrides Sub RegisterOutputParams(pManager As Kernel.GH_Component.GH_OutputParamManager)

End Sub
Protected Overrides Sub SolveInstance(DA As Kernel.IGH_DataAccess)

End Sub
End Class