Named Expression Syntax

Question

Using AECOSIM CONNECT UPDATE 1 | Windows 8.1 
 Trying to customize some ribbon buttons using Named expressions. What I want to do is recognize a portion of a file name and if it matches show a button and if not don't show a specific button. 
 I have spent a significant amount of time and tried many different possibilities (substring, length -, getfilenamewithoutextension and others) and all have given me grief. 
 I feel the approaches below have been the most promising, because the individual pieces seem to work. However when I combine and click the Test button to evaluate, I get a "can not evaluate expression" error instead of a true or false. 
 System.String.IndexOf(ConfigVar.GetExpandedConfigVar("_DGNFILE"), &rdquo;_GUI.DGNLIB&rdquo;) > 0 
 System.String.IndexOf(System.String.ToString(ConfigVar.GetExpandedConfigVar("_DGNFILE"), &rdquo;_GUI.DGNLIB&rdquo;)) > 0 
 What am I doing wrong? 
 Thanks in advance 
 Keith

Keith Ouellet · Answer

Figured out my own solution add to incorporate a system.string.substring and do a compare to the string returned. as shown below. 
 System.String.SubString(ConfigVar.GetExpandedConfigVar("_DGNFILE"), System.String.IndexOf (ConfigVar.GetExpandedConfigVar("_DGNFILE") , "_GUI.DGNLIB"), -1)="_GUI.DGNLIB" 
 Thanks to anyone who was looking into. 
 Keith

Jan Šlegr · Answer

Hi Keith, 
 I was not able to answer earlier because of different time zone. It's good to know you found the solution, but in my opinion it can implemented in better way. 
 I see two situation when the used approach will not work properly: 
 
 The comparison is not case insensitive, so "_GUI.DGNLIB" will work but "_gui.dgnlib" not. My experience is that it's hard to fulfill a policy whether the letter are always capitals, so it's better to use case insensitive comparisons. 
 It will not work with "crazy file names" like myfile_gui.dgnlib_test_gui.dgnlib, because you tested the first occurence of "_gui.dgnlib" string and not the last one. It can be solve using .LastIndexOf method instead of .IndexOf. 
 
 There is another solution using different approach: 
 System.String.CompareI(System.String.Substring (ConfigVar.GetExpandedConfigVar("_DGNFILE"),System.String.Length(ConfigVar.GetExpandedConfigVar("_DGNFILE"))-11, -1),"_GUI.DGNLIB") 
 To decode this train wrack (which is usually treated as dirty code, but there is no other solution how to keep everything in one line ;-) 
 
 ConfigVar.GetExpandedConfigVar("_DGNFILE") ... _DGNFILE is expanded to the full path 
 System.String.Length(ConfigVar.GetExpandedConfigVar("_DGNFILE")) ... the full path length (number of characters) 
 Length - 11 is an index where "_gui.dgnlib" substring starts. 
 System.String.Substring(...) ... takes the whole path and produces substring from (length - 11) position to the end of the string, which is expected to be "_gui.dgnlib" or "_GUI.DGNLIB". 
 System.String.CompareI(...) ... provides case insensitive string comparison, so a result is indifferent whether the substring is in capital letters or no. 
 
 With regards, 
 Jan