ORD 2021 R1 (10.10.01.03) - Item Types - Element Length Expression

Question

Hi All, 
 I am currently using ORD 2021 R1 (10.10.01.03). 
 Does anyone know if there is an Item Types expression that can be used to determine the "length" of an element in a corridor model? 
 I thought I might be able to get the value using a System.Math expression and the Start Station and End Station values but that didn't seem to work. 
 Any ideas/suggestions would be appreciated. 
 Regards, 
 Ryan

Sanjivani Ichake · Answer

Hi Ryan, 
 As discussed over email, below GetRelatedInstance symbol expression will help you to fetch Length of continuous or non continuous mesh element. 
 
this.GetRelatedInstance("OnSameElement:0:MeshSurfaceEntity").GetRelatedInstance("Component__Entity_Embedding:1:Corridor").GetRelatedInstance("Component__Entity_Embedding:0:LinearEntity3d").GetElement().LinearElement_Length3d

 
 I am adding these details here, just to inform other guys about this use case solution and about new blog of GetRelatedInstance expression. This will help them to refer it for future use cases. 
 Above expression looks pretty complex as there are various relationships involved. To form such expressions, you will need some understanding of internal relationships between elements. To get insight into relationships, we have key-in &ldquo;ecx items dump&rdquo; which dumps all instance data of dgn file in one xml file. I have published one blog recently to give an overview of how to use GetRelatedInstance and how to use the ecx item dump tool. Here is the blog link: 
 Creating-item-type-expression-with-GetrRlatedInstance 
 Regards, Sanjivani