topic Built in Family Parameters auto creation issues in Revit API Forum

Built in Family Parameters auto creation issues

rafael_guerra — Mon, 10 Jul 2017 17:40:40 GMT

Hi to Everyone,

I have created a family wich has several nested families within itself. Each family has a parameter which is then linked to a new parameter created in the nesting family in order to control the "base parameter". However, By some reason two of my linked parameters Length and Width have become Built-in Revit Parameters. Apparently, by some reason, my instance parameters have been linked to a built-in parameter of length and width respectively within Revit. I haven't been able to figure out whether this has happened due to a Revit bug or it is actually something Revit intend for users to be able to do.

Any help on this issue will be greatly appreciated.

Re: Built in Family Parameters auto creation issues

Revitalizer — Fri, 28 Jul 2017 15:39:16 GMT

Hi Rafael,

I faced a similar problem when creating lamp families in Revit 2015.

I needed to add a parameter named "Lampe" which was also the German equivalent for a "Lamp" BuiltInParameter.

(As far as I remember, Revit created a parameter named "Lampe2" instead, but I may fail).

I think the problem depends on two circumstances: the UI language and the family template.

When opening your family in my German Revit, there is no parameter "Length" and "Width" since these BuiltInParameters are translated at runtime:

Depending on the language Revit is run, if you try to get a parameter by its name, you may get null or not.

I suppose that if you run Revit in another language than English, you can add "Width" and "Length" without problems.

But when opening the resulting family just in an English Revit, you will either have two "Width" parameters, or one of them will be renamed (temporarily?).

Since the "Width" and "Length" parameters are very generic, I suppose you will hardly find another family template to use instead.

It is possible to use a template of another category and change this category afterwards, resulting in missing BuiltInParameters:

https://forums.autodesk.com/t5/revit-api-forum/wall-closure-parameter-doesn-t-exist/td-p/7250962

So, how to solve the problem ?

Just use parameter names that don't match BuiltInParameter translations.

Revitalizer

Re: Built in Family Parameters auto creation issues

rafael_guerra — Fri, 28 Jul 2017 16:16:33 GMT

Thanks for your explanation, now I can confidently say it is more a bug found in Revit rather than an exploitable capability.