topic Determine if Category has Tag assigned to it in Revit API Forum

Determine if Category has Tag assigned to it

mhillis — Wed, 01 Nov 2017 20:47:55 GMT

Hello all,

Very simple question here; I've been experimenting with Annotations in Revit and using the API to automatically put down tags onto objects in the Project space. Which is simple enough, but I'm stuck on finding a way to determine whether or not an object type has a tag assigned to it before we use the create new Indepedent Tag function.

I've become farmiliar with Jeremy Tammik's post here - http://thebuildingcoder.typepad.com/blog/2010/06/set-tag-type.html which goes over the process of changing a Tag type for a category after it has been placed, however; if for some reason a project does not have a tag family assigned to a category, you can't actually put down a tag.

How would I go about checking, and possibly adding, for a tag family on a category before I try placing one?

Thanks.

Re: Determine if Category has Tag assigned to it

eason.kangEDLV4 — Sun, 05 Nov 2017 09:35:49 GMT

Before attaching a IndependentTag to a element, you can do following steps to check if a tag element connected with a specific element:

Use FilteredElementCollector to collect IndependentTag in current document or current view, then extract ElementId which represents associated elements (such as doors, windows) from IndependentTag.TaggedElementIdor IndependentTag.TaggedLocalElementId.
Check ElementIds of picked elements if they are contained in the id list from the step1. If yes, then exclude this element from your tag creation task or abort any tag creation operations. What to do is up to you.
Or, implement ISelectionFilter based on id list from the step1 to exclude elements in this list, and pass it into your element picking operation. Then you will obtain elements without a tag attached.

Hope it helps.

Cheers,

Re: Determine if Category has Tag assigned to it

FAIR59 — Tue, 07 Nov 2017 00:12:24 GMT

If there are tags loaded for a category, then there exists a tag Family. You can make a collector for families, checking for the tagcategory. if the collector doesn't find families, then there is no tag Family loaded.

			StringBuilder sb = new StringBuilder();
			List<string> tempList = new List<string>();
			foreach (Category cat in document.Settings.Categories)
			{
				if (!cat.IsTagCategory) continue;
				Family  categorytagFamily = new FilteredElementCollector(document)
					.OfClass(typeof(Family))
					.Cast<Family>()
					.Where( f => f.FamilyCategory.Id.IntegerValue == cat.Id.IntegerValue)
					.FirstOrDefault();
				if (categorytagFamily!=null)
					tempList.Add(string.Format("<{0}> {1}, there are tags loaded",(BuiltInCategory)cat.Id.IntegerValue,cat.Name));
			}
			tempList.Sort();
			foreach( string s in tempList) sb.AppendLine(s);
			TaskDialog.Show("tagList", sb.ToString());

Re: Determine if Category has Tag assigned to it

mhillis — Sun, 12 Nov 2017 19:26:23 GMT

@FAIR59 wrote:

			StringBuilder sb = new StringBuilder();
			List<string> tempList = new List<string>();
			foreach (Category cat in document.Settings.Categories)
			{
				if (!cat.IsTagCategory) continue;
				Family  categorytagFamily = new FilteredElementCollector(document)
					.OfClass(typeof(Family))
					.Cast<Family>()
					.Where( f => f.FamilyCategory.Id.IntegerValue == cat.Id.IntegerValue)
					.FirstOrDefault();
				if (categorytagFamily!=null)
					tempList.Add(string.Format("<{0}> {1}, there are tags loaded",(BuiltInCategory)cat.Id.IntegerValue,cat.Name));
			}
			tempList.Sort();
			foreach( string s in tempList) sb.AppendLine(s);
			TaskDialog.Show("tagList", sb.ToString());

I apologize to all for how long this took to reply to, but I wanted to update and inform everyone that this method gave me exactly what I was looking for. A quick note, for those who are using 2014, the Category.IsTagCategory property does not exist (it was added in 2015 it seems); however, an extremely simple work around, I've found is simply checking to see if the Category.Name field contains the text "Tags".