property |NSURL| : a reference to current application’s |NSURL|
property PDFDocument : a reference to current application’s PDFDocument
property titleList : {}

set my titleList to {}

set aFile to POSIX path of (choose file of type {"com.adobe.pdf"})

set fileURL to |NSURL|’s fileURLWithPath:aFile
set aPDFdoc to PDFDocument’s alloc()’s initWithURL:fileURL

–TOCの読み込み
set parentOL to aPDFdoc’s outlineRoot() –あらかじめTOCが存在していないとmissing valueになる
if parentOL is equal to missing value then
　　display dialog "本PDFにはTOCが添付されていないため、処理を終了します" with title "No TOC Error:"
　　return
end if

getChilds(parentOL) of me
return (my titleList)

–再帰処理してみた
on getChilds(parentOL)
　　set outLineStr to parentOL’s label()
　　set outLineCount to (parentOL’s numberOfChildren()) as number
　　
　　repeat with i from 0 to (outLineCount – 1)
　　　　set anOut to (parentOL’s childAtIndex:i)
　　　　set tmpOut to (anOut’s label()) as string
　　　　set the end of my titleList to tmpOut
　　　　set tmpChild to (anOut’s numberOfChildren()) as integer
　　　　
　　　　if tmpChild is not equal to 0 then
　　　　　　getChilds(anOut) of me
　　　　end if
　　end repeat
end getChilds