File/Folder Read Permissions

eYe · 2008-11-27

Is there a way to determine whether or not a user has read permission to a folder without causing an error message to be displayed?

  lRecCurrentDir.SETRANGE(Path, pRecSubFolder.Path + '\' + pRecSubFolder.Name);
  IF lRecCurrentDir.FINDFIRST THEN
   BEGIN
    ...

lRecCurrentDir is a record variable, subtype File.
If the path filtered on is not accessable, the system gives a message: "Operating System cannot gain access to...".
But it proceeds with the rest of the code.

Fred_CIT · 2008-11-27

The only solution I can come up with is placing code for checking the permissions of a folder in a codeunit and call it like this:

IF CODEUNIT.RUN(...) THEN
BEGIN
// Permissions OK
..
END
ELSE
BEGIN
// Error on permissions
..
END;

But for sending the necessary parameters to the codeunit you will be limited using just 1 record (Although there is a workaround for this using a single instance codeunit).
If you want you can get the precise error using the GETLASTERRORTEXT function.

garak · 2008-11-27

Sorry, thats not so easy.

The only way i know is with (C#)

System.IO.Directory.GetAccessControl and there the error handling

so you can also open a CMD with using WSH and WSHExec, check what, for example, "net use" return (or other net commands), and do the rest ....

Or place your codesnippes in a Codeunit and rund the Codeunit with:

If Not Codeunit.run then
message('Sorry, Folder not exist or permission denied');

Regards.

eYe · 2008-11-27

System.IO.Directory.GetAccessControl is only a .NET framework2 dll, and you can't register it in NAV

The Microsoft Scripting and Windows Scripting automations don't help either... ](*,)

The problem isn't the error handling. It is getting the system (NAV) to throw an error that I will be able to handle, rather than displaying a Windows message and proceeding with the NAV code without breaking.

eYe · 2008-12-01

Okay, I kinda found a workaround to this.

Using the 'Microsoft Shell Controls And Automation', you can do the following:

[b]Name	                DataType	Subtype[/b]
lAutFolder	        Automation	'Microsoft Shell Controls And Automation'.Folder2	
lAutFolderItems	Automation	'Microsoft Shell Controls And Automation'.FolderItems3	
lAutFolderItem	Automation	'Microsoft Shell Controls And Automation'.FolderItem	

[b]GetFolderItems(VAR pAutFolderItem : Automation "'Microsoft Shell Controls And Automation'.FolderItem")[/b]

IF ISCLEAR(pAutFolderItem) THEN
 lAutFolder := gAutMSShell.NameSpace(gDriveLetter)
ELSE
 lAutFolder := gAutMSShell.NameSpace(pAutFolderItem.Path);

lAutFolderItems := lAutFolder.Items;
FOR i := 0 TO lAutFolderItems.Count - 1  DO
 BEGIN
  lAutFolderItem := lAutFolderItems.Item(i);

  IF lAutFolderItem.IsFolder AND
     (STRPOS(UPPERCASE(lAutFolderItem.Name), '.ZIP') = 0) AND
     (lAutFolderItem.Name = DELCHR(lAutFolderItem.Name, '=', '&:|?*')) 
  THEN
     GetFolderItems(lAutFolderItem)
  ELSE
     DoFileAction(lAutFolderItem);
 END;

The automation automatically skips the folders it does not have access to.
NOTE: The automation treats ZIP files as a folder, and has trouble with certain tipes of folders e.g. in your WINDOWS folder there is a folder called "assembly", it is of type Folder and not File Folder, the automation has trouble with those, also it does not like certain CHARs in the folder name.

You can also use:

lAutFolder_FolderItems.Filter(63, '*.*'); //Applies a filter to get only FolderItems that are folders
lAutFile_FolderItems.Filter(64, '*.flf'); //Applies a filter to get only FolderItems that are files of type .flf

eYe · 2008-12-01

This is something very strange:
In the solution I gave above (just add a window.update in the FOR loop), the code does not work when in a table, but works 100% in a codeunit:

I have function A, that sets certain global variables (amongst which VAR Window of type Dialog) and then calls function GetFolderItems, that calls itself recursively.

After an unknown amount of recursive loops (this appears to happen randomly), all my global variables seem to get cleared. I promise you, I don't clear it in function GetFolderItems.

e.g. after a couple of loops it gives an error on the Window.update that the form/dialog box is not open.

After moving this code from the table to a codunit, it seems to be working :shock: ... Why is this?

kine · 2008-12-01

Can you post more complex part of the code?

eYe · 2008-12-01

There is nothing more complex to this. the "DoFile" function checks whether the FolderItem.Name contains .flf, if so, create a log entry.

kine · 2008-12-01

Sorry, I forgot to scroll the code subwindow... :oops:

Sog · 2008-12-01

You can follow in the debugger how many times the function calls itself.
I think (I don't have any grounds for it, it's actually a hunch) that it can call itself so many times as there are records in the table, even though you don't loop trough them. After that it might clear all variables. But when you put the code in a codeunit it works. (as you've stated)
The only difference between a codeunit and a table is that the one doesn't have records while the other one has and that is what started my train of thought.

eYe · 2008-12-01

I created a new table with the following functions, and called start from a CU. With or without records, it runs through. :-k

Start()
Window.OPEN('TEST #1#############');
gTotal := 20;
i := 1;
RecursiveFunction(i);


RecursiveFunction(VAR pCounter : Integer)
IF pCounter > gTotal THEN
 EXIT;

pCounter += 1;
Window.UPDATE(1, pCounter);
RecursiveFunction(pCounter);

LOL, change the 20 to 2000....
NAV closes without an error....?

kriki · 2008-12-02

eYe wrote:

LOL, change the 20 to 2000....
NAV closes without an error....?

That is probably because you have a stack-overflow. But I thought NAV gave a message about that. Which version did you use?

eYe · 2008-12-03

NAV 4 SP1 native.

4SP1 does have the stack overflow message (add currform.update(false) to .OnAfterGetRecord...)

Anyway, I suspect I found the problem with the code on the table, the "DoFileAction" function inserts a record into the same db as it is running the code from and has a commit at the end. Could the insert and/or the commit clear the variables - moving to a seperate instance of the table itself somehow? (haven't tested this though, already moved the code to a CU)

kriki · 2009-06-17

[Topic moved from 'NAV/Navision' forum to 'NAV Tips & Tricks' forum]

File/Folder Read Permissions

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