Applescript is not always setting my variable to the clipboard - applescript

Question

I'm trying to set up an Indesign script that copies the link information of a selected image and appends it to a text file to the desktop, if the text file does not exist it creates one. The link information is copied to the clipboard using a custom key command in inDesign. The problem is if I copy some text or an image beforehand, that text remains on the clipboard. Even though I copy new link info and set that clipboard to a variable.
I know this is an ugly script, I'm just good enough to get by, but barely.
Any suggestions on how to clear out the clipboard?
Thanks,
~David
--dialog box
display dialog "What do you need done" default answer "Remove Background"
set theAnswer to (text returned of result)
set this_story to "
------------------- " & theAnswer & " -------------------
"
set this_file to (((path to desktop folder) as string) & "Corrections.txt")
my write_to_file(this_story, this_file, false)
on write_to_file(this_data, target_file, append_data)
try
set the target_file to the target_file as string
set the open_target_file to open for access file target_file with write permission
if append_data is true then set eof of the open_target_file to 0
write this_data to the open_target_file starting at eof
close access the open_target_file
return true
on error
try
close access file target_file
end try
return false
end try
end write_to_file
--copy link information using keyboard short
activate application "Adobe InDesign CC 2015"
tell application "System Events" to keystroke "l" using {shift down, control down}
end
---
set myVar to the clipboard
my write_clip_file(myVar, this_file, false)
on write_clip_file(myVar, target_file, append_data)
try
set the target_file to the target_file as string
set the open_target_file to open for access file target_file with write permission
if append_data is true then set eof of the open_target_file to 0
write myVar to the open_target_file starting at eof
close access the open_target_file
return true
on error
try
close access file target_file
end try
return false
end try
end write_clip_file

Answer 1

Here is a cleaned up version of your script. You don't need to code the same handler twice... both times you right to the file, you can use the same handler. Also, I reversed the logic on the append_data variable, because you had the logic backwards. (if you DO append, then you DON'T set eof to 0 cause that erases the current content).
I don't know what function you're calling in InDesign, but sounds like it's placing the file path/link of a selected image onto the clipboard. When using the clipboard to get data and to place the data into a variable, it's a good practice to put some delays in the script, to avoid the script moving on to the next commands before the app you're working with finishes it's work. I'm betting that the problem you're having is that the script is proceeding before InDesign has finished copying to the clipboard. So, in this script, you can see I placed three delays surrounding the work with the clipboard. You can play with reducing the delay times to see what will still work reliably.
--dialog box
display dialog "What do you need done" default answer "Remove Background"
set theAnswer to (text returned of result)
set this_story to "
------------------- " & theAnswer & " -------------------
"
set this_file to (((path to desktop folder) as string) & "Corrections.txt")
my write_to_file(this_story, this_file, true)
--copy link information using keyboard short
tell application "Adobe InDesign CC 2015"
-- tell application "TextEdit" -- for testing purposes
activate
delay 0.9 -- give app time to come to the front before copying to clipboard
tell application "System Events" to keystroke "l" using {shift down, control down}
-- tell application "System Events" to keystroke "c" using {command down} -- for testing purposes
delay 0.9 -- wait til clipboard is copied before continuing with the script
end tell
set myVar to the clipboard
delay 0.1 -- wait til variable is pulled from clipboard before moving on
my write_to_file(myVar, this_file, true)
--
on write_to_file(this_data, target_file, append_data)
try
set the target_file to the target_file as string
set the open_target_file to open for access file target_file with write permission
if append_data is false then set eof of the open_target_file to 0
write this_data to the open_target_file starting at eof
close access the open_target_file
return true
on error
try
close access file target_file
end try
return false
end try
end write_to_file
Try this out and tweak it as you need to, and then let me know if anything is still not working.