How to find out whether a given ID is a Folder or a Document

Question

I have an ID. It's currently an integer. 
 I want to know if there's a Document with that ID, or if there's a Folder with that ID. Why? Because if I guess and try to put it in the document() function, it will crash if it's a folder. If I guess and try to put it in the folder() function, it will crash if it's a document. 
 I've tried plugins, but the plugins have a super fun tendency to throw lots of Java errors destroying our logs whenever we try to find out if this stupid thing is a Document or a Folder. 
 Is there a way to do this out of the box? I want a rule that receives an integer and outputs the word "Document" or the word "Folder" or the word "Neither" and DOES NOT PINK BOX no matter what integer is.

Mike Schmitt · Answer

AFAIK you want Content Tools , and probably its function getContentObjectDetailsById() , which will return a string containing various properties (including type) of the ID you passed in. 
 I've whipped up a sample expression rule using this functionality that will return "Document" (plaintext) when the ID type is Document, "Folder" for a folder, and if no type is found, it will return the text "Invalid". I forget off the top of my head whether any other object types will return (maybe KCs too?). In any case it should work and hopefully won't clutter log files with too much junk, though that's usually something I worry about a lot later than getting functionality to actually work... 
 a!localVariables(
 local!details: getcontentobjectdetailsbyid(ri!objectId),
 local!extractedType: extract(local!details, "Type: ", ", Created"),
 
 index(local!extractedType, 1, "Invalid")
)