Apple Script runs more than once when file is opened - macos

Question

I have a piece of code which is used as a folder action and constantly watches the folder. When a new file is placed in the folder, the script runs and outputs a dialog box. The user can either open or print the file from the dialog box. However, when I select the open button, the code then produces the dialog box again when the a new file hasn't been opened. This only occurs when the file is opened and not when it is printed.
Can anyone help? Code is below
on adding folder items to theAttachedFolder after receiving theNewItems
set filepath to theNewItems as string
if filepath contains "HA" then
set theDialogText to "HA is in file name"
do shell script "afplay '/System/Library/Sounds/Submarine.aiff'"
display dialog theDialogText buttons {"Dismiss", "Print", "Go to "} default button "Go to order" with icon note
if result = {button returned:"Go to"} then
tell application "Finder"
open file filepath
end tell
else if result = {button returned:"Print"} then
tell application "Shelf Label Printer"
activate
print filepath
quit
end tell
display dialog "Printed" with icon note
end if
if filepath contains "OG" then
set theDialogText to "OG is in file name"
do shell script "afplay '/System/Library/Sounds/Submarine.aiff'"
display dialog theDialogText buttons {"Dismiss", "Print", "Go to"} default button "Go to order" with icon note
if result = {button returned:"Go to"} then
tell application "Finder"
open file filepath
end tell
else if result = {button returned:"Print"} then
tell application "Shelf Label Printer"
activate
print filepath
quit
end tell
display dialog "Printed" with icon note
Edit: Mojave is running on the iMac in question.

Answer 1

There were a few problematic points in this code, any of which could produce odd behavior, so I cleaned it up so that it works correctly on my machine. New code first, then bullet points on what I changed...
on adding folder items to theAttachedFolder after receiving theNewItems
repeat with thisItem in theNewItems
set filepath to POSIX path of thisItem as string
if filepath contains "HA" or filepath contains "OG" then
set theDialogText to "HA or OG is in file name"
do shell script "afplay '/System/Library/Sounds/Submarine.aiff'"
tell application "System Events"
display dialog theDialogText buttons {"Dismiss", "Print", "Go to"} default button 3 with icon note
end tell
if result = {button returned:"Go to"} then
tell application "System Events"
open file filepath
end tell
else if result = {button returned:"Print"} then
tell application "Shelf Label Printer"
activate
print filepath
quit
end tell
display dialog "Printed" with icon note
end if
end if
end repeat
end adding folder items to
"after receiving" always gives a list of aliases, even if it's a single item, so we should loop through the list rather than trying to convert it directly to string.
You duplicated the same code for 'HA' and 'OG' files, so I merged them
Your Display Dialog cited the default button as "Go to order" when your buttons were "Dismiss", "Print", "Go to". That was throwing an error (Display Dialog wants an exact match to one of the buttons). I replaced that with the index 3.
Folder Actions and the Finder do not always play well together, so I switched to the System Events app for the dialogs and the file open procedure.
This should work properly now...