Revised Return Document Reference

I was using this function in a script and noticed when it was passed a collections such as you get with .pages, it didn't return a document reference. This version does this. The version posted back on June 27, 2009 has been removed.

function returnDocumentReference ( anObject ) {

//-------------------------------------------------------------------------

//-- R E T U R N D O C U M E N T R E F E R E N C E

//-------------------------------------------------------------------------

//-- Generic: Yes for most versions of Adobe InCopy or Adobe InDesign.

//-------------------------------------------------------------------------

//-- Purpose: To return a document reference for the passed object.

//-------------------------------------------------------------------------

//-- Returns: A reference to the document holding the passed object

//-- providing the object is within 32 levels of the Document

//-- or returns null if the docucment cannot be found or if an

//-- error occurs.

//-------------------------------------------------------------------------

//-- Sample Use:

//-- var docRef = returnDocumentReference ( app.selection[0] )

//-------------------------------------------------------------------------

//-- Calls: Nothing.

//-------------------------------------------------------------------------

//-- This function is not recursive, but instead loops through the

//-- object's parents, grandparents, etc. until reaching something

//-- whose constructor's name includes 'Document'. What is

//-- interesting about the function is that it is generic enough

//-- that you could easily swap the word 'Document' for another

//-- type of object. However, in Adobe InDesign and Adobe InCopy

//-- not all objects below pages have constructors.

//-------------------------------------------------------------------------

//-- Written: by Jon S. Winters

//-- Unsure of original date, but edited on 2009.09.14 in New Orleans, LA

//-- eps@electronicpublishingsupport.com

//-------------------------------------------------------------------------

// Provide an excape hatch incase something goes astray

var loopLimit = 32 ;

// Create a Regular Expression pattern

// for a case insensitive word 'Document'

var docPattern = new RegExp ( 'Document' , 'i' ) ;

// Start with the object itself incase it is the document.

var possibleDocument = anObject ;

// in case something really odd is sent, wrap in error handler

try {

// Continue looping up and chacking the parents until

// a matching document is found.

while ( ( ! docPattern.test( possibleDocument.constructor.name ) ) && ( loopLimit-- > 0 ) ){

//-- 2009.09.14 Below generates false error when a collection is passed

//-- such as .pages

try {

possibleDocument = possibleDocument.parent ;

}

catch (err ) {

//-- if the error deals with a collection of objects

//-- then try to get the parent of the first item.

if ( possibleDocument.length > 1 ) {

possibleDocument = possibleDocument[0].parent ;

}

else { return null ; } ;

}

}

// Check the loop limit and either return the document or null

if ( loopLimit > 0 ) {

return possibleDocument ; }

else { return null ; }

}

catch (err) { return null ; }

}// end of function

//