Using a thread to monitor if file is open

[Mike Wilson]

I am trying to monitor if a Word Document is open so when it is closed, I can change the file attributes to read only. I have been reading about threads but don't really understand them. I figured I could open a thread that continuously monitors the file_is_open() with a if-then loop, and when .f. engage action (file attribute change) and close the thread. I can't see that a thread can be closed from within the thread, or how to monitor that the thread is open, or when it is ended. I have the following that I can't seem to monitor. Any help is appreciated.

dim vfile as C
vfile=vdoc_folder_path+"POL_BB_D991_20100427.doc"

dim thread_name as C
thread_name = "WORD PROBE"
 
dim thread_code as C
thread_code = <<%code%
dim thread_run_flag as L = .t.
while thread_run_flag
RUNAGAIN:
    'the file open
    if file_is_open(vfile)
		GOTO RUNAGAIN
	else
		thread_variables("WORD PROBE").thread_run_flag := .f.
                          msgbox("file closed")
	end if
end while
%code%

thread_create(thread_name, thread_code)

[Stan Mathews]

Re: Using a thread to monitor if file is open

I can't see that a thread can be closed from within the thread

This does that.

thread_variables("WORD PROBE").thread_run_flag := .f.

how to monitor that the thread is open

You have to check with

THREAD_IS_RUNNING()

I don't think you can have the thread notify you that it has ended because "No user interface related commands are allowed in a thread".

Does the user who has the doc open always make a change? You might try using file.watch_create().

[Lenny Forziati]

Re: Using a thread to monitor if file is open

• Get rid of the goto. Having the while loop handles rechecking the file and your goto bypasses the while loop, so that thread_run_flag has no ability to stop the thread.
• Add a sleep in the loop so the thread doesn't consume too much CPU and prevent other threads from executing.
• The thread will exit when the script runs to completion, so an exit while is all that is needed to end the thread.
• If you want to toggle the thread_run_flag variable, refer to it simply as that. There is no need to use thread_variables("WORD PROBE").thread_run_flag since you are in that thread.
• As Stan pointed out, you can't use msgbox or other UI functions in your thread.

dim vfile as C
vfile=vdoc_folder_path+"POL_BB_D991_20100427.doc"

dim thread_name as C
thread_name = "WORD PROBE"
 
dim thread_code as C
thread_code = <<%code%
dim thread_run_flag as L = .t.
while thread_run_flag
    'the file open
    if file_is_open(vfile)
		sleep(.5)
                'after the sleep, the while loop is executed again
	else
		exit while
	end if
end while
%code%

thread_create(thread_name, thread_code)

[csda1]

Re: Using a thread to monitor if file is open

Hi Mike,

Threads are tricky if you haven't got a good handle on it. You can also consider using

File.Watch_create()

[Mike Wilson]

Re: Using a thread to monitor if file is open

Lenny, Stan, Ira,
Thank you. Lenny, your directions were super! I got that to work almost 100%. I have an issue with differences with behavior depending which MS Word version is used (at least I believe this the case). I have Office 97 (OK, it's 12 years old but it still works for me). Client uses Word 2000. The order of the functions firing makes a difference.

thread_script()
sys_open(file)

This doesn't work since the thread_script has the checking for the doc being opened, and if closed fires the code to file.attribute_set(file,"+R"), it always opens the file read only.

sys_open(file)
thread_script()

This opens the Word app and starts the thread but the focus ends on A5 app not the Word doc opened (not in Word 97 but yes with Word 2000). So now I'm hunting a command to set focus back to the open Word window. Haven't found one yet, but I know I have one in this app somewhere (age don't you know).

Ira,
Yes that function I checked out with Stan's mention of it in his above thread. The flag parameter I need is not provided for.. file open. I'll keep plugging away.

Thanks all.

dim thread_name as C
thread_name = "WORD PROBE"
 dim thread_code as C

thread_code = <<%code%
dim thread_run_flag as L = .t.
while thread_run_flag
    'the file open
    if file_is_open(vfile)                 ' vfile comes from calling script
		sleep(3)
         'after the sleep, the while loop is executed again
   	else
   		file.attributes_set(vfile,"+R")
		exit while
	end if
end while
%code%

thread_create(thread_name, thread_code)

[G Gabriel]

Re: Using a thread to monitor if file is open

While you are at it (I was going to suggest file watch, Ira already did) so just to add one more to the mix you could use process_list() although I think it's a little slow, maybe too slow.

Instead of monitoring the file, why not check the file attribute:

psuedo_code:
if attribute = this
change attribute to that
end if

That said, I am not really sure what's the overall objective. Is it that you want to make the file read only?
How about attaching a password to the file instead?

[Mike Wilson]

Re: Using a thread to monitor if file is open

Gabriel,
Just to be honorable... STAN shared the file watch first...;)

12 users (supervisors) have access to documents in the administrative side of this document control app. The documents are divided among 10 section of the department. They are policies. Each user has privileges (responsibility) to read-write to certain sections only, althought they need read rights to all. I wish to store all the documents in a read-only state and if the user has privileges to a document in their section, it will be opened read-write. Otherwise read-only. I have this worked out well. What I'm working on is for the event of the document opening under the user that has read-write privileges, after they are completed with their edits and save the doc and close the Word app, I want the attributes of that doc converted back to read only. So I need to monitor when the file under edit becomes no longer open (closed), and then fire the code to convert the attribute to read-only. The thread startegy seemed like a possibility, and I'm getting it to work. Now I just need a window_get_focus() command to have focus back to the Word window after the thread script is called, which takes focus back to A5.

[G Gabriel]

Re: Using a thread to monitor if file is open

Is it one Word document with 12 sections? or 12 separate documents?

[Mike Wilson]

Re: Using a thread to monitor if file is open

G,
The document pile in this department is about 1100 documents total and growing. It is one document per section (about 110/section) x # of sections (10) = 1100 total. About 10% of total belong to each of 10 sections. Every document requires review and review signature by supervisor and director every year (annual reviews) with revisions as needed, and every 5 year renewals (complete rewrites due to technology advancements). This is just one department. Once the document control is present in one deartment, there are a dozen other departments available to expand this to. Just so it is clear... I am the director having to sign all these documents and I want......a better way than paper and folders all over my office!!

[G Gabriel]

Re: Using a thread to monitor if file is open

Mike:
I go back to password.

Word allows you to assign a password to open and/or to edit the document which seems to be what you need here.

I am not in favor of anything running in the background or any OnTimer event unless absolutely necessary.

[Lenny Forziati]

Re: Using a thread to monitor if file is open

sys_focus_put()

[Mike Wilson]

Re: Using a thread to monitor if file is open

G,
I somewhat share your reluctance of having running background threads but I have to weigh that against having to script interractions with Word. I do not know MS Basic and want to keep coding between A5 and Word to absolute minimum.

Lenny,
Thanks. I appreciate that. When I read that, it immediately dawned on me where I have used it in this very application. But I was struggling. I think I've got it working pretty well now. Thanks for the lift.