Trouble with NSWorkspace's recycleURLs:completionHandler: method

[leonsimard]

Hello,

I’m trying to explore ASOC a little bit more everyday and was now trying to replace the old applescript way:

tell application "Finder" to move finderPathOfCurrentItemToTrash to the trash

with a more ASOC way of doing it. I have this code:

set theWorkspace to current application's NSWorkspace's sharedWorkspace()
set theNewURLsDictionary to current application's NSDictionary's dictionary()
set theErrorObject to current application's NSError's errorWithDomain_code_userInfo_((current application's NSPOSIXErrorDomain), 1, missing value)
set theMoveToTrashResults to theWorkspace's recycleURLs_completionHandler_({currentEntryPathURL}, theNewURLsDictionary, theErrorObject)

but i get a crash with no errors. Anyone has an idea as to what I may be doing wrong? Right now I am passing a one item array composed of an NSURL object initialized like this:

set currentEntryPathURL to current application's |NSURL|'s fileURLWithPath_isDirectory_(currentEntryPath, true)

I tried passing an NSString before but didn’t seem to work.

Am i pushing beyond the limits of ASOC??

Thanks for any help.

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[leonsimard]

Yeah, after a bit more of reading I found this in the docs:

Moving Files to the Trash
You use recycleURLs:completionHandler: to move files at the specified URLs to the trash in the same manner as the Finder. The completion handler argument is a block object that is invoked when the operation has finished.

If I am not mistaken, blocks are a no-no in ASOC, right?

But maybe this would work:

Mac OS X v10.5 and earlier: To move items to the trash in Mac OS X v10.5 and earlier, you can use the NSWorkspace method performFileOperation:source:destination:files:tag: method specifying NSWorkspaceRecycleOperation as the operation.

arguments-wise it’s all good except for the last one, tag. In the docs it says:

On input, a integer variable; on return, this variable contains a negative integer if the operation fails, 0 if the operation was performed synchronously and succeeded, or a positive integer if the operation was performed asynchronously. If the value is a positive integer, the value is a tag that identifies the requested file operation.

how would I specify a variable to pass as an argument? Initialize an NSInteger object perhaps? And how would I read this variable back? Maybe like this?

set theMoveToTrashResults to theWorkspace's performFileOperation_source_destination_files_tag_(current application's NSWorkspaceRecycleOperation, {currentEntryPathURLParentFolder}, missing value, {currentEntryPathURL}, NSIntegerObject)

and this destination argument gets me puzzled. What is the URL for the trash? I passed missing value here but maybe it’ll fail…

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Operating System: Mac OS X (10.6)

[leonsimard]

Got it to work with this change:

set theMoveToTrashResults to theWorkspace's recycleURLs_completionHandler_({currentEntryPathURL}, missing value)

but now I do not get any feedback as to the success or failure of the move. Would a try on error help in this case?

One huge advantage: you don’t hear that annoying sound when files are moved to trash by the finder with this…

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[rdelmar]

but now I do not get any feedback as to the success or failure of the move. Would a try on error help in this case?

I don’t think that will help. You were right about blocks and ASOC – you can’t do blocks, and if the method you are using is working, it’s only because you are allowed to pass a nil for the block if you don’t care about the results. You’ll have to use ObjC if you want to see the results of the operation, and if there were any errors.

Ric

[Shane_Stanley]

As you said, blocks are out, so recycleURLs_completionHandler_ will only work with missing value as the second argument. There’s no way you can get feedback without blocks here, although I suppose you could check the old path and be pretty safe in assuming that if it’s not there, it’s worked. The problem, though, is that the command is asynchronous, so you won’t know quite when to check.

performFileOperation:source:destination:files:tag: should be OK. The problem with the tag argument is that it’s a pointer to a C type, not to an object. There is a workaround for this, but it’s not intuitive. Have a look at the Reference chapter ‘What Methods Can Return’. So something like this (untested):

set {theMoveToTrashResults,theTag} to theWorkspace's performFileOperation_source_destination_files_tag_(current application's NSWorkspaceRecycleOperation, currentEntryPathURLParentFolder, "", {"File 1","File 2"}, reference)

[Shane_Stanley]

BTW, you might find it a bit easier to use NSFileManger and moveItemAtURL:toURL:error: or moveItemAtPath:toPath:error:.

[leonsimard]

Interesting… i’ll look that up for sure. But one final question: is there a constant or something that could give me the correct URL to the trash? Looked in the docs, saw nothing that could help… Then, where is it located really? I assume it is a hidden folder that starts with a dot somewhere in the user’s folder… has anyone seen the trash?

Thanks everyone! This has been very instructive post for me.

Good night

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[Shane_Stanley]

path to trash

[leonsimard]

Obvious to the point where it pokes your eyes… I was thinking more in the Obj-C world, but that’ll do. Seems to simply be “~/.Trash”, which makes it universal. Excellent. Thanks!

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