property |NSURL| : a reference to current application’s |NSURL|
property NSArray : a reference to current application’s NSArray
property NSString : a reference to current application’s NSString
property NSPredicate : a reference to current application’s NSPredicate
property PDFDocument : a reference to current application’s PDFDocument
property NSSortDescriptor : a reference to current application’s NSSortDescriptor
property NSURLTypeIdentifierKey : a reference to current application’s NSURLTypeIdentifierKey
property NSRegularExpressionSearch : a reference to current application’s NSRegularExpressionSearch

–set inFiles to (choose file of type {"pdf"} with prompt "Choose your PDF files:" with multiple selections allowed)
tell application "Finder"
　　set inFiles to selection as alias list
end tell

if inFiles = {} then
　　display dialog "No PDF Selection on Finder…" with icon 1
　　return
end if

–指定のAlias listのうちPDFのみ抽出
set filRes1 to filterAliasListByUTI(inFiles, "com.adobe.pdf") of me

set totalP to 0

repeat with i in filRes1
　　set tmpCount to pdfPageCount(contents of i) of me
　　if tmpCount > 0 then
　　　　set totalP to totalP + tmpCount
　　end if
end repeat

display dialog "Total Pages:" default answer (totalP as string) with icon 1

–指定PDFのページ数をかぞえる（10.9対応。普通にPDFpageから取得）
–返り値：PDFファイルのページ数（整数値）
on pdfPageCount(aFile)
　　set theURL to |NSURL|’s fileURLWithPath:aFile
　　set aPDFdoc to PDFDocument’s alloc()’s initWithURL:theURL
　　set aRes to aPDFdoc’s pageCount()
　　return aRes as integer
end pdfPageCount

–Alias listから指定UTIに含まれるものをPOSIX pathのリストで返す
on filterAliasListByUTI(aList, targUTI)
　　set newList to {}
　　repeat with i in aList
　　　　set j to POSIX path of i
　　　　set tmpUTI to my retUTIfromPath(j)
　　　　set utiRes to my filterUTIList({tmpUTI}, targUTI)
　　　　if utiRes is not equal to {} then
　　　　　　set the end of newList to j
　　　　end if
　　end repeat
　　return newList
end filterAliasListByUTI

–指定のPOSIX pathのファイルのUTIを求める
on retUTIfromPath(aPOSIXPath)
　　set aURL to |NSURL|’s fileURLWithPath:aPOSIXPath
　　set {theResult, theValue} to aURL’s getResourceValue:(reference) forKey:NSURLTypeIdentifierKey |error|:(missing value)
　　
　　if theResult = true then
　　　　return theValue as string
　　else
　　　　return theResult
　　end if
end retUTIfromPath

–UTIリストが指定UTIに含まれているかどうか演算を行う
on filterUTIList(aUTIList, aUTIstr)
　　set anArray to NSArray’s arrayWithArray:aUTIList
　　set aPred to NSPredicate’s predicateWithFormat_("SELF UTI-CONFORMS-TO %@", aUTIstr)
　　set bRes to (anArray’s filteredArrayUsingPredicate:aPred) as list
　　return bRes
end filterUTIList

–リストに入れたレコードを、指定の属性ラベルの値でソート
on sortRecListByLabel(aRecList as list, aLabelStr as string, ascendF as boolean)
　　set aArray to NSArray’s arrayWithArray:aRecList
　　set sortDesc to NSSortDescriptor’s alloc()’s initWithKey:aLabelStr ascending:ascendF
　　–set sortDescArray to current application’s NSArray’s arrayWithObjects:sortDesc–macOS 11でクラッシュ
　　set sortedArray to aArray’s sortedArrayUsingDescriptors:{sortDesc}
　　return sortedArray
end sortRecListByLabel