Named Expressions - Want to Show and Hide Menus Based upon Starting Characters of Active File Name

Question

We use a DOT provided workspace which uses VBA to load various Barmenu files. The Macro reads the file name and grabs the initial three characters and loads the MDF files based upon what it finds. 
 I would like to migrate that to named expressions with menu customizations that use a show and hide toggle based upon the named expression. This seems like a natural progression since we can import the Barmenu files using one of the Bentley utilities. 
 This will be my first venture into Named Expressions, so I am looking for any suggestions or caveats that may burst my bubble. 
 TIA.

Jan Šlegr · Accepted Answer

Hi caddcop, 
 welcome in Named Expression adventure! ;-) 
 The Named Expression with the required functionality is System.String.CompareI(System.String.Substring(System.Path.GetFileName(ActiveFile.FileName),0,3),"AAA") , where "AAA" is 3 chars long tested string. 
 Because as you told you have just begun with the expression, here is the functionality explanation, going from inside to outside: 
 
 ActiveFile.FileName - Returns a full name of the active file including path. 
 System.Path.GetFileName(path) - Extracts only file name including extension from the full file name. In this case, from e.g. c:\myfiles\mydrawing.dgn you will receive mydrawing.dgn. 
 System.String.Substring (value,startIndex,length) - Extracts only specified substring (from startIndex) from input string (defined in value). In this case, it takes short file name (mydrawing.dgn) and extracts 3 chars long string from the beginning (the index is zero-based, so 0 means the first char). 
 System.String.CompareI (string1,string2) - It does case insensitive comparison of two strings. If they match, true is returned, otherwise false. I use case insensitive comparison, because it's usually not important if the file name is mydrawing.dgn or MyDrawing.dgn. If you want to use case sensitive comparison, use System.String.Compare (without I at the end). 
 
 Attached is captured Named Expressions dialog, don't forget to check User interface keyword, so the expression will be displayed as available test in Customize dialog. 
 With regards, 
 Jan

Marc Thomas · Answer

To hide the ABD specific tools I needed a named expression that would test for the presence of ABD. ABD has it's own set of Named Expressions that do not exist in MicroStation They included: 
 
 BD_IsAppLoadedArch 
 BD_IsAppLoadedElec 
 BD_IsAppLoadedMech 
 BD_IsAppLoadedStr 
 
 that check which of the four disciplines is loaded. 
 I wanted one that would show my menu items when any of the disciplines were loaded so created a new named expression that included the expressions from all four of the above. 
 The new expression is stored in the dgnlib that contains the menu so it travels with the menu.