topic Add/Set a System Pipes Custom Parameters in Revit API Forum

Add/Set a System Pipes Custom Parameters

Anonymous — Sun, 08 Sep 2013 23:52:10 GMT

Hello

Is it possible to add a custom parameter to a System Pipe? I have successfully added many shared parameters to the shared parameter file. And I am also able to set a FamilyInstances' shared parameter (called 'Chainage').

But I am unable to set a System Pipes shared parameter 'Chainage'. It throws the exception:

Object reference not set to an instance of an object

This error has occurred before when I tried to set a parameter that doesn't exist. Is it possible to add and set a custom parameter to a System Pipe? If so how do I do it?

My below code successfully registers some shared parameters, successfully sets a FamilyInstance's shared param but fails when I try to set a System Pipes same shared param:

public static FamilyInstance createPit(Document doc, XmlNode pitNode, XmlNamespaceManager nsmgr)
{
	if (!setupSharedParameters(doc))
		return null;

	// Create family instance and set param: Succeeds
	double x            = getXmlNodeDouble(pitNode, "ns:x", nsmgr);
	double y            = getXmlNodeDouble(pitNode, "ns:y", nsmgr);
	double z            = getXmlNodeDouble(pitNode, "ns:z", nsmgr);
	FamilyInstance instance = doc.Create.NewFamilyInstance(new XYZ(x, y, z), pitSymbol, StructuralType.NonStructural);
	instance.get_Parameter("Road Name").Set("IRULE");
	
	// Create System pipe and set param: Fails
	Pipe pipe = doc.Create.NewPipe(new XYZ(x, y, z), new XYZ(x+10, y, z), pipeType);
        // Note pipe exists and is not null
	pipe.get_Parameter("Road Name").Set("IRULE"); // ERROR OCCURS HERE
	return instance;
}

public static bool setupSharedParameters(Document doc)
{
	try
	{
		if (SHARED_PARAMS_SETUP)
			return SHARED_PARAMS_SETUP;

		//prepare shared parameter file
		String path         = Assembly.GetExecutingAssembly().Location;
		int index           = path.LastIndexOf("\\");
		String newPath      = path.Substring(0, index);
		newPath            += "\\RevitParameters.txt";
		
		if (File.Exists(newPath))
			File.Delete(newPath);

		FileStream fs = File.Create(newPath);
		fs.Close();
		doc.Application.SharedParametersFilename = newPath;

		//Open shared parameter file
		DefinitionFile parafile = doc.Application.OpenSharedParameterFile();

		//get walls category
		Category wallCat = doc.Settings.Categories.get_Item(BuiltInCategory.OST_PlumbingFixtures); //  .OST_Walls);
		CategorySet categories = doc.Application.Create.NewCategorySet();
		categories.Insert(wallCat);

		InstanceBinding binding = doc.Application.Create.NewInstanceBinding(categories);

		//Create a group
		DefinitionGroup apiGroup = parafile.Groups.Create("APIGroup");

		//Create a visible "VisibleParam" of text type.
		BindingMap bindingMap = doc.ParameterBindings;
		Definition visibleParamDef = apiGroup.Definitions.Create("Type", ParameterType.Text, true);
		bindingMap.Insert(visibleParamDef, binding);
		visibleParamDef = apiGroup.Definitions.Create("Chainage", ParameterType.Number, true);
		bindingMap.Insert(visibleParamDef, binding);
		visibleParamDef = apiGroup.Definitions.Create("Road Name", ParameterType.Text, true);
		bindingMap.Insert(visibleParamDef, binding);
		
		SHARED_PARAMS_SETUP = true;
		return SHARED_PARAMS_SETUP;
	}
	catch (Exception e)
	{
		return false;
	}
}

Re: Add/Set a System Pipes Custom Parameters

ollikat — Mon, 09 Sep 2013 05:16:33 GMT

Hi

Yes you can have shared parameter for pipes. You just need to use BuiltInCategory.OST_PipeCurves category in the binding.

Re: Add/Set a System Pipes Custom Parameters

Anonymous — Mon, 09 Sep 2013 05:50:15 GMT

Thanks for the reply 🙂

I altered my code so that the plumbing fixture category is used in the binding. And then finally altered/set a pipes params but the parameter is not appearing in the properties tab (when I select the pipe).

Note: the shared parameters are visible and the error I mentioned above still occurs.

Any ideas what I am doing wrong?

My code:

public static bool setupSharedParameters(Document doc)
{
	try
	{
		if (SHARED_PARAMS_SETUP)
			return SHARED_PARAMS_SETUP;

		//prepare shared parameter file
		String path         = Assembly.GetExecutingAssembly().Location;
		int index           = path.LastIndexOf("\\");
		String newPath      = path.Substring(0, index);
		newPath            += "\\RevitParameters.txt";
		
		if (File.Exists(newPath))
			File.Delete(newPath);

		FileStream fs = File.Create(newPath);
		fs.Close();
		doc.Application.SharedParametersFilename = newPath;

		//Open shared parameter file
		DefinitionFile parafile = doc.Application.OpenSharedParameterFile();

		Category plumbCat       = doc.Settings.Categories.get_Item(BuiltInCategory.OST_PlumbingFixtures);
		Category pipeCat        = doc.Settings.Categories.get_Item(BuiltInCategory.OST_PipeCurves);
		CategorySet categories  = doc.Application.Create.NewCategorySet();
		//categories.Insert(plumbCat);
		categories.Insert(pipeCat);

		InstanceBinding binding = doc.Application.Create.NewInstanceBinding(categories);

		//Create a group
		DefinitionGroup apiGroup = parafile.Groups.Create("APIGroup");

		//Create a visible "VisibleParam" of text type.
		BindingMap bindingMap = doc.ParameterBindings;
		Definition visibleParamDef = apiGroup.Definitions.Create("Type", ParameterType.Text, true);
		bindingMap.Insert(visibleParamDef, binding);
		visibleParamDef = apiGroup.Definitions.Create("Name", ParameterType.Text, true);
		bindingMap.Insert(visibleParamDef, binding);
		SHARED_PARAMS_SETUP = true;
		return SHARED_PARAMS_SETUP;
	}
	catch (Exception e)
	{
		return false;
	}
}

Re: Add/Set a System Pipes Custom Parameters

Anonymous — Mon, 09 Sep 2013 06:18:03 GMT

Actually there error I get is different. The error is:

This element does not support assignment of a user specified-name