From script to Folder Action?

Question

Sample script:
tell application "Finder"
set List1 to {"VNG", "COW", "SIN", "CVR", "CRM"}
set List2 to {"VNG", "SIN"}
set MissingList to {}
repeat with i from 1 to count of List1
if item i of List1 is not in List2 then
set end of MissingList to item i of List1
end if
end repeat
display dialog MissingList as text
end tell
Works, gives me what I want - answer as "COW, CVR, CRM"
I make a Folder Action from it, like this:
on adding folder items to this_folder after receiving added_items
tell application "Finder"
set List1 to {"VNG", "COW", "SIN", "CVR", "CRM"}
set List2 to {"VNG", "SIN"}
set MissingList to {}
repeat with i from 1 to count of List1
if item i of List1 is not in List2 then
set end of MissingList to item i of List1
end if
end repeat
display dialog MissingList as text
end tell
end adding folder items to
Attach it to the folder, try - the answer comes as ""COWCVRCRM", without separating items in a list.
Why?
And, BTW, when I work with script I can see an Event Log in a Script Editor, but when Folder Action works - is there any way to see a Log?
Thank you in advance for any help!
Vera

Answer 1

It may be that displaying the dialog via Script Editor instead of whatever app is frontmost when your folder action is triggered causes the difference. It's been known to happen. Try this in place of your code to display the dialog (untested code).
<pre style="
font-family: Monaco, 'Courier New', Courier, monospace;
font-size: 10px;
margin: 0px;
padding: 5px;
border: 1px solid #FF0000;
width: 720px;
color: #000000;
background-color: #ffff99;
overflow: auto;">
set {oldDelims, my text item delimiters} to {my text item delimiters, {", "}}
display dialog (items of MissingList) as text
set my text item delimiters to oldDelims</pre>
As for seeing your events, you can write code that can send some of it to a file on the desktop but you won't get all of it, mostly just error info. The best way I know of is to use [Script Debugger|http://www.latenightsw.com/sd4/index.html|http://www.latenightsw.com/s d4/index.html] from Late Night Software Ltd. It may seem expensive initially but it's worth every penny you'll spend on it. Note: the SD download is completely functional for 20 days after installation so you can give it a good workout. Its debugging environment will allow you to step through every line of code, see your variable results for each line and also concurrently view the event log.